diff mbox

[v6,8/8] mfd: Add support for Intel Sunrisepoint LPSS devices

Message ID 1438009443-55317-9-git-send-email-andriy.shevchenko@linux.intel.com (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Andy Shevchenko July 27, 2015, 3:04 p.m. UTC
The new coming Intel platforms such as Skylake will contain Sunrisepoint PCH.
The main difference to the previous platforms is that the LPSS devices are
compound devices where usually main (SPI, HSUART, or I2C) and DMA IPs are
present.

This patch brings the driver for such devices found on Sunrisepoint PCH.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
 drivers/mfd/Kconfig           |  23 ++
 drivers/mfd/Makefile          |   3 +
 drivers/mfd/intel-lpss-acpi.c |  84 +++++++
 drivers/mfd/intel-lpss-pci.c  | 113 +++++++++
 drivers/mfd/intel-lpss.c      | 524 ++++++++++++++++++++++++++++++++++++++++++
 drivers/mfd/intel-lpss.h      |  62 +++++
 6 files changed, 809 insertions(+)
 create mode 100644 drivers/mfd/intel-lpss-acpi.c
 create mode 100644 drivers/mfd/intel-lpss-pci.c
 create mode 100644 drivers/mfd/intel-lpss.c
 create mode 100644 drivers/mfd/intel-lpss.h

Comments

Lee Jones July 28, 2015, 7:48 a.m. UTC | #1
On Mon, 27 Jul 2015, Andy Shevchenko wrote:

> The new coming Intel platforms such as Skylake will contain Sunrisepoint PCH.
> The main difference to the previous platforms is that the LPSS devices are
> compound devices where usually main (SPI, HSUART, or I2C) and DMA IPs are
> present.
> 
> This patch brings the driver for such devices found on Sunrisepoint PCH.
> 
> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> ---
>  drivers/mfd/Kconfig           |  23 ++
>  drivers/mfd/Makefile          |   3 +
>  drivers/mfd/intel-lpss-acpi.c |  84 +++++++
>  drivers/mfd/intel-lpss-pci.c  | 113 +++++++++
>  drivers/mfd/intel-lpss.c      | 524 ++++++++++++++++++++++++++++++++++++++++++
>  drivers/mfd/intel-lpss.h      |  62 +++++
>  6 files changed, 809 insertions(+)
>  create mode 100644 drivers/mfd/intel-lpss-acpi.c
>  create mode 100644 drivers/mfd/intel-lpss-pci.c
>  create mode 100644 drivers/mfd/intel-lpss.c
>  create mode 100644 drivers/mfd/intel-lpss.h

Applied, thanks.  Pull request to follow.

> diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
> index 6538159..268b6dd 100644
> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -328,6 +328,29 @@ config INTEL_SOC_PMIC
>  	  thermal, charger and related power management functions
>  	  on these systems.
>  
> +config MFD_INTEL_LPSS
> +	tristate
> +	select COMMON_CLK
> +	select MFD_CORE
> +
> +config MFD_INTEL_LPSS_ACPI
> +	tristate "Intel Low Power Subsystem support in ACPI mode"
> +	select MFD_INTEL_LPSS
> +	depends on X86 && ACPI
> +	help
> +	  This driver supports Intel Low Power Subsystem (LPSS) devices such as
> +	  I2C, SPI and HS-UART starting from Intel Sunrisepoint (Intel Skylake
> +	  PCH) in ACPI mode.
> +
> +config MFD_INTEL_LPSS_PCI
> +	tristate "Intel Low Power Subsystem support in PCI mode"
> +	select MFD_INTEL_LPSS
> +	depends on X86 && PCI
> +	help
> +	  This driver supports Intel Low Power Subsystem (LPSS) devices such as
> +	  I2C, SPI and HS-UART starting from Intel Sunrisepoint (Intel Skylake
> +	  PCH) in PCI mode.
> +
>  config MFD_INTEL_MSIC
>  	bool "Intel MSIC"
>  	depends on INTEL_SCU_IPC
> diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
> index ea40e07..9d730a2 100644
> --- a/drivers/mfd/Makefile
> +++ b/drivers/mfd/Makefile
> @@ -161,6 +161,9 @@ obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
>  obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
>  obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
>  obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
> +obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
> +obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
> +obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)	+= intel-lpss-acpi.o
>  obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
>  obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
>  obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
> diff --git a/drivers/mfd/intel-lpss-acpi.c b/drivers/mfd/intel-lpss-acpi.c
> new file mode 100644
> index 0000000..0d92d73
> --- /dev/null
> +++ b/drivers/mfd/intel-lpss-acpi.c
> @@ -0,0 +1,84 @@
> +/*
> + * Intel LPSS ACPI support.
> + *
> + * Copyright (C) 2015, Intel Corporation
> + *
> + * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> + *          Mika Westerberg <mika.westerberg@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pm.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/platform_device.h>
> +
> +#include "intel-lpss.h"
> +
> +static const struct intel_lpss_platform_info spt_info = {
> +	.clk_rate = 120000000,
> +};
> +
> +static const struct acpi_device_id intel_lpss_acpi_ids[] = {
> +	/* SPT */
> +	{ "INT3446", (kernel_ulong_t)&spt_info },
> +	{ "INT3447", (kernel_ulong_t)&spt_info },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(acpi, intel_lpss_acpi_ids);
> +
> +static int intel_lpss_acpi_probe(struct platform_device *pdev)
> +{
> +	struct intel_lpss_platform_info *info;
> +	const struct acpi_device_id *id;
> +
> +	id = acpi_match_device(intel_lpss_acpi_ids, &pdev->dev);
> +	if (!id)
> +		return -ENODEV;
> +
> +	info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
> +			    GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	info->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	info->irq = platform_get_irq(pdev, 0);
> +
> +	pm_runtime_set_active(&pdev->dev);
> +	pm_runtime_enable(&pdev->dev);
> +
> +	return intel_lpss_probe(&pdev->dev, info);
> +}
> +
> +static int intel_lpss_acpi_remove(struct platform_device *pdev)
> +{
> +	intel_lpss_remove(&pdev->dev);
> +	pm_runtime_disable(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +static INTEL_LPSS_PM_OPS(intel_lpss_acpi_pm_ops);
> +
> +static struct platform_driver intel_lpss_acpi_driver = {
> +	.probe = intel_lpss_acpi_probe,
> +	.remove = intel_lpss_acpi_remove,
> +	.driver = {
> +		.name = "intel-lpss",
> +		.acpi_match_table = intel_lpss_acpi_ids,
> +		.pm = &intel_lpss_acpi_pm_ops,
> +	},
> +};
> +
> +module_platform_driver(intel_lpss_acpi_driver);
> +
> +MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
> +MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
> +MODULE_DESCRIPTION("Intel LPSS ACPI driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/mfd/intel-lpss-pci.c b/drivers/mfd/intel-lpss-pci.c
> new file mode 100644
> index 0000000..9236dff
> --- /dev/null
> +++ b/drivers/mfd/intel-lpss-pci.c
> @@ -0,0 +1,113 @@
> +/*
> + * Intel LPSS PCI support.
> + *
> + * Copyright (C) 2015, Intel Corporation
> + *
> + * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> + *          Mika Westerberg <mika.westerberg@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +#include <linux/pm.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "intel-lpss.h"
> +
> +static int intel_lpss_pci_probe(struct pci_dev *pdev,
> +				const struct pci_device_id *id)
> +{
> +	struct intel_lpss_platform_info *info;
> +	int ret;
> +
> +	ret = pcim_enable_device(pdev);
> +	if (ret)
> +		return ret;
> +
> +	info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
> +			    GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	info->mem = &pdev->resource[0];
> +	info->irq = pdev->irq;
> +
> +	/* Probably it is enough to set this for iDMA capable devices only */
> +	pci_set_master(pdev);
> +
> +	ret = intel_lpss_probe(&pdev->dev, info);
> +	if (ret)
> +		return ret;
> +
> +	pm_runtime_put(&pdev->dev);
> +	pm_runtime_allow(&pdev->dev);
> +
> +	return 0;
> +}
> +
> +static void intel_lpss_pci_remove(struct pci_dev *pdev)
> +{
> +	pm_runtime_forbid(&pdev->dev);
> +	pm_runtime_get_sync(&pdev->dev);
> +
> +	intel_lpss_remove(&pdev->dev);
> +}
> +
> +static INTEL_LPSS_PM_OPS(intel_lpss_pci_pm_ops);
> +
> +static const struct intel_lpss_platform_info spt_info = {
> +	.clk_rate = 120000000,
> +};
> +
> +static const struct intel_lpss_platform_info spt_uart_info = {
> +	.clk_rate = 120000000,
> +	.clk_con_id = "baudclk",
> +};
> +
> +static const struct pci_device_id intel_lpss_pci_ids[] = {
> +	/* SPT-LP */
> +	{ PCI_VDEVICE(INTEL, 0x9d27), (kernel_ulong_t)&spt_uart_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d28), (kernel_ulong_t)&spt_uart_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d29), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d2a), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d60), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d61), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d62), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d63), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d64), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d65), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0x9d66), (kernel_ulong_t)&spt_uart_info },
> +	/* SPT-H */
> +	{ PCI_VDEVICE(INTEL, 0xa127), (kernel_ulong_t)&spt_uart_info },
> +	{ PCI_VDEVICE(INTEL, 0xa128), (kernel_ulong_t)&spt_uart_info },
> +	{ PCI_VDEVICE(INTEL, 0xa129), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0xa12a), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0xa160), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0xa161), (kernel_ulong_t)&spt_info },
> +	{ PCI_VDEVICE(INTEL, 0xa166), (kernel_ulong_t)&spt_uart_info },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(pci, intel_lpss_pci_ids);
> +
> +static struct pci_driver intel_lpss_pci_driver = {
> +	.name = "intel-lpss",
> +	.id_table = intel_lpss_pci_ids,
> +	.probe = intel_lpss_pci_probe,
> +	.remove = intel_lpss_pci_remove,
> +	.driver = {
> +		.pm = &intel_lpss_pci_pm_ops,
> +	},
> +};
> +
> +module_pci_driver(intel_lpss_pci_driver);
> +
> +MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
> +MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
> +MODULE_DESCRIPTION("Intel LPSS PCI driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
> new file mode 100644
> index 0000000..fdf4d5c
> --- /dev/null
> +++ b/drivers/mfd/intel-lpss.c
> @@ -0,0 +1,524 @@
> +/*
> + * Intel Sunrisepoint LPSS core support.
> + *
> + * Copyright (C) 2015, Intel Corporation
> + *
> + * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> + *          Mika Westerberg <mika.westerberg@linux.intel.com>
> + *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
> + *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clkdev.h>
> +#include <linux/clk-provider.h>
> +#include <linux/debugfs.h>
> +#include <linux/idr.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mfd/core.h>
> +#include <linux/pm_qos.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/seq_file.h>
> +
> +#include "intel-lpss.h"
> +
> +#define LPSS_DEV_OFFSET		0x000
> +#define LPSS_DEV_SIZE		0x200
> +#define LPSS_PRIV_OFFSET	0x200
> +#define LPSS_PRIV_SIZE		0x100
> +#define LPSS_IDMA64_OFFSET	0x800
> +#define LPSS_IDMA64_SIZE	0x800
> +
> +/* Offsets from lpss->priv */
> +#define LPSS_PRIV_RESETS		0x04
> +#define LPSS_PRIV_RESETS_FUNC		BIT(2)
> +#define LPSS_PRIV_RESETS_IDMA		0x3
> +
> +#define LPSS_PRIV_ACTIVELTR		0x10
> +#define LPSS_PRIV_IDLELTR		0x14
> +
> +#define LPSS_PRIV_LTR_REQ		BIT(15)
> +#define LPSS_PRIV_LTR_SCALE_MASK	0xc00
> +#define LPSS_PRIV_LTR_SCALE_1US		0x800
> +#define LPSS_PRIV_LTR_SCALE_32US	0xc00
> +#define LPSS_PRIV_LTR_VALUE_MASK	0x3ff
> +
> +#define LPSS_PRIV_SSP_REG		0x20
> +#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN	BIT(0)
> +
> +#define LPSS_PRIV_REMAP_ADDR_LO		0x40
> +#define LPSS_PRIV_REMAP_ADDR_HI		0x44
> +
> +#define LPSS_PRIV_CAPS			0xfc
> +#define LPSS_PRIV_CAPS_NO_IDMA		BIT(8)
> +#define LPSS_PRIV_CAPS_TYPE_SHIFT	4
> +#define LPSS_PRIV_CAPS_TYPE_MASK	(0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)
> +
> +/* This matches the type field in CAPS register */
> +enum intel_lpss_dev_type {
> +	LPSS_DEV_I2C = 0,
> +	LPSS_DEV_UART,
> +	LPSS_DEV_SPI,
> +};
> +
> +struct intel_lpss {
> +	const struct intel_lpss_platform_info *info;
> +	enum intel_lpss_dev_type type;
> +	struct clk *clk;
> +	struct clk_lookup *clock;
> +	const struct mfd_cell *cell;
> +	struct device *dev;
> +	void __iomem *priv;
> +	int devid;
> +	u32 caps;
> +	u32 active_ltr;
> +	u32 idle_ltr;
> +	struct dentry *debugfs;
> +};
> +
> +static const struct resource intel_lpss_dev_resources[] = {
> +	DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
> +	DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
> +	DEFINE_RES_IRQ(0),
> +};
> +
> +static const struct resource intel_lpss_idma64_resources[] = {
> +	DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
> +	DEFINE_RES_IRQ(0),
> +};
> +
> +#define LPSS_IDMA64_DRIVER_NAME		"idma64"
> +
> +/*
> + * Cells needs to be ordered so that the iDMA is created first. This is
> + * because we need to be sure the DMA is available when the host controller
> + * driver is probed.
> + */
> +static const struct mfd_cell intel_lpss_idma64_cell = {
> +	.name = LPSS_IDMA64_DRIVER_NAME,
> +	.num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
> +	.resources = intel_lpss_idma64_resources,
> +};
> +
> +static const struct mfd_cell intel_lpss_i2c_cell = {
> +	.name = "i2c_designware",
> +	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
> +	.resources = intel_lpss_dev_resources,
> +};
> +
> +static const struct mfd_cell intel_lpss_uart_cell = {
> +	.name = "dw-apb-uart",
> +	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
> +	.resources = intel_lpss_dev_resources,
> +};
> +
> +static const struct mfd_cell intel_lpss_spi_cell = {
> +	.name = "pxa2xx-spi",
> +	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
> +	.resources = intel_lpss_dev_resources,
> +};
> +
> +static DEFINE_IDA(intel_lpss_devid_ida);
> +static struct dentry *intel_lpss_debugfs;
> +
> +static int intel_lpss_request_dma_module(const char *name)
> +{
> +	static bool intel_lpss_dma_requested;
> +
> +	if (intel_lpss_dma_requested)
> +		return 0;
> +
> +	intel_lpss_dma_requested = true;
> +	return request_module("%s", name);
> +}
> +
> +static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
> +{
> +	lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
> +	lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
> +}
> +
> +static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
> +{
> +	struct dentry *dir;
> +
> +	dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
> +	if (IS_ERR(dir))
> +		return PTR_ERR(dir);
> +
> +	/* Cache the values into lpss structure */
> +	intel_lpss_cache_ltr(lpss);
> +
> +	debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
> +	debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
> +	debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
> +
> +	lpss->debugfs = dir;
> +	return 0;
> +}
> +
> +static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
> +{
> +	debugfs_remove_recursive(lpss->debugfs);
> +}
> +
> +static void intel_lpss_ltr_set(struct device *dev, s32 val)
> +{
> +	struct intel_lpss *lpss = dev_get_drvdata(dev);
> +	u32 ltr;
> +
> +	/*
> +	 * Program latency tolerance (LTR) accordingly what has been asked
> +	 * by the PM QoS layer or disable it in case we were passed
> +	 * negative value or PM_QOS_LATENCY_ANY.
> +	 */
> +	ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
> +
> +	if (val == PM_QOS_LATENCY_ANY || val < 0) {
> +		ltr &= ~LPSS_PRIV_LTR_REQ;
> +	} else {
> +		ltr |= LPSS_PRIV_LTR_REQ;
> +		ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
> +		ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
> +
> +		if (val > LPSS_PRIV_LTR_VALUE_MASK)
> +			ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
> +		else
> +			ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
> +	}
> +
> +	if (ltr == lpss->active_ltr)
> +		return;
> +
> +	writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
> +	writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
> +
> +	/* Cache the values into lpss structure */
> +	intel_lpss_cache_ltr(lpss);
> +}
> +
> +static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
> +{
> +	lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
> +	dev_pm_qos_expose_latency_tolerance(lpss->dev);
> +}
> +
> +static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
> +{
> +	dev_pm_qos_hide_latency_tolerance(lpss->dev);
> +	lpss->dev->power.set_latency_tolerance = NULL;
> +}
> +
> +static int intel_lpss_assign_devs(struct intel_lpss *lpss)
> +{
> +	unsigned int type;
> +
> +	type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
> +	type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
> +
> +	switch (type) {
> +	case LPSS_DEV_I2C:
> +		lpss->cell = &intel_lpss_i2c_cell;
> +		break;
> +	case LPSS_DEV_UART:
> +		lpss->cell = &intel_lpss_uart_cell;
> +		break;
> +	case LPSS_DEV_SPI:
> +		lpss->cell = &intel_lpss_spi_cell;
> +		break;
> +	default:
> +		return -ENODEV;
> +	}
> +
> +	lpss->type = type;
> +
> +	return 0;
> +}
> +
> +static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
> +{
> +	return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
> +}
> +
> +static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
> +{
> +	resource_size_t addr = lpss->info->mem->start;
> +
> +	writel(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR_LO);
> +#if BITS_PER_LONG > 32
> +	writel(addr >> 32, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
> +#else
> +	writel(0, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
> +#endif
> +}
> +
> +static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
> +{
> +	u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
> +
> +	/* Bring out the device from reset */
> +	writel(value, lpss->priv + LPSS_PRIV_RESETS);
> +}
> +
> +static void intel_lpss_init_dev(const struct intel_lpss *lpss)
> +{
> +	u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
> +
> +	intel_lpss_deassert_reset(lpss);
> +
> +	if (!intel_lpss_has_idma(lpss))
> +		return;
> +
> +	intel_lpss_set_remap_addr(lpss);
> +
> +	/* Make sure that SPI multiblock DMA transfers are re-enabled */
> +	if (lpss->type == LPSS_DEV_SPI)
> +		writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
> +}
> +
> +static void intel_lpss_unregister_clock_tree(struct clk *clk)
> +{
> +	struct clk *parent;
> +
> +	while (clk) {
> +		parent = clk_get_parent(clk);
> +		clk_unregister(clk);
> +		clk = parent;
> +	}
> +}
> +
> +static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
> +					     const char *devname,
> +					     struct clk **clk)
> +{
> +	char name[32];
> +	struct clk *tmp = *clk;
> +
> +	snprintf(name, sizeof(name), "%s-enable", devname);
> +	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
> +				lpss->priv, 0, 0, NULL);
> +	if (IS_ERR(tmp))
> +		return PTR_ERR(tmp);
> +
> +	snprintf(name, sizeof(name), "%s-div", devname);
> +	tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
> +					      0, lpss->priv, 1, 15, 16, 15, 0,
> +					      NULL);
> +	if (IS_ERR(tmp))
> +		return PTR_ERR(tmp);
> +	*clk = tmp;
> +
> +	snprintf(name, sizeof(name), "%s-update", devname);
> +	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
> +				CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
> +	if (IS_ERR(tmp))
> +		return PTR_ERR(tmp);
> +	*clk = tmp;
> +
> +	return 0;
> +}
> +
> +static int intel_lpss_register_clock(struct intel_lpss *lpss)
> +{
> +	const struct mfd_cell *cell = lpss->cell;
> +	struct clk *clk;
> +	char devname[24];
> +	int ret;
> +
> +	if (!lpss->info->clk_rate)
> +		return 0;
> +
> +	/* Root clock */
> +	clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL,
> +				      CLK_IS_ROOT, lpss->info->clk_rate);
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +
> +	snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
> +
> +	/*
> +	 * Support for clock divider only if it has some preset value.
> +	 * Otherwise we assume that the divider is not used.
> +	 */
> +	if (lpss->type != LPSS_DEV_I2C) {
> +		ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
> +		if (ret)
> +			goto err_clk_register;
> +	}
> +
> +	ret = -ENOMEM;
> +
> +	/* Clock for the host controller */
> +	lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
> +	if (!lpss->clock)
> +		goto err_clk_register;
> +
> +	lpss->clk = clk;
> +
> +	return 0;
> +
> +err_clk_register:
> +	intel_lpss_unregister_clock_tree(clk);
> +
> +	return ret;
> +}
> +
> +static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
> +{
> +	if (IS_ERR_OR_NULL(lpss->clk))
> +		return;
> +
> +	clkdev_drop(lpss->clock);
> +	intel_lpss_unregister_clock_tree(lpss->clk);
> +}
> +
> +int intel_lpss_probe(struct device *dev,
> +		     const struct intel_lpss_platform_info *info)
> +{
> +	struct intel_lpss *lpss;
> +	int ret;
> +
> +	if (!info || !info->mem || info->irq <= 0)
> +		return -EINVAL;
> +
> +	lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
> +	if (!lpss)
> +		return -ENOMEM;
> +
> +	lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
> +				  LPSS_PRIV_SIZE);
> +	if (!lpss->priv)
> +		return -ENOMEM;
> +
> +	lpss->info = info;
> +	lpss->dev = dev;
> +	lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
> +
> +	dev_set_drvdata(dev, lpss);
> +
> +	ret = intel_lpss_assign_devs(lpss);
> +	if (ret)
> +		return ret;
> +
> +	intel_lpss_init_dev(lpss);
> +
> +	lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
> +	if (lpss->devid < 0)
> +		return lpss->devid;
> +
> +	ret = intel_lpss_register_clock(lpss);
> +	if (ret)
> +		goto err_clk_register;
> +
> +	intel_lpss_ltr_expose(lpss);
> +
> +	ret = intel_lpss_debugfs_add(lpss);
> +	if (ret)
> +		dev_warn(dev, "Failed to create debugfs entries\n");
> +
> +	if (intel_lpss_has_idma(lpss)) {
> +		/*
> +		 * Ensure the DMA driver is loaded before the host
> +		 * controller device appears, so that the host controller
> +		 * driver can request its DMA channels as early as
> +		 * possible.
> +		 *
> +		 * If the DMA module is not there that's OK as well.
> +		 */
> +		intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);
> +
> +		ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
> +				      1, info->mem, info->irq, NULL);
> +		if (ret)
> +			dev_warn(dev, "Failed to add %s, fallback to PIO\n",
> +				 LPSS_IDMA64_DRIVER_NAME);
> +	}
> +
> +	ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
> +			      1, info->mem, info->irq, NULL);
> +	if (ret)
> +		goto err_remove_ltr;
> +
> +	return 0;
> +
> +err_remove_ltr:
> +	intel_lpss_debugfs_remove(lpss);
> +	intel_lpss_ltr_hide(lpss);
> +
> +err_clk_register:
> +	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(intel_lpss_probe);
> +
> +void intel_lpss_remove(struct device *dev)
> +{
> +	struct intel_lpss *lpss = dev_get_drvdata(dev);
> +
> +	mfd_remove_devices(dev);
> +	intel_lpss_debugfs_remove(lpss);
> +	intel_lpss_ltr_hide(lpss);
> +	intel_lpss_unregister_clock(lpss);
> +	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
> +}
> +EXPORT_SYMBOL_GPL(intel_lpss_remove);
> +
> +static int resume_lpss_device(struct device *dev, void *data)
> +{
> +	pm_runtime_resume(dev);
> +	return 0;
> +}
> +
> +int intel_lpss_prepare(struct device *dev)
> +{
> +	/*
> +	 * Resume both child devices before entering system sleep. This
> +	 * ensures that they are in proper state before they get suspended.
> +	 */
> +	device_for_each_child_reverse(dev, NULL, resume_lpss_device);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(intel_lpss_prepare);
> +
> +int intel_lpss_suspend(struct device *dev)
> +{
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(intel_lpss_suspend);
> +
> +int intel_lpss_resume(struct device *dev)
> +{
> +	struct intel_lpss *lpss = dev_get_drvdata(dev);
> +
> +	intel_lpss_init_dev(lpss);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(intel_lpss_resume);
> +
> +static int __init intel_lpss_init(void)
> +{
> +	intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
> +	return 0;
> +}
> +module_init(intel_lpss_init);
> +
> +static void __exit intel_lpss_exit(void)
> +{
> +	debugfs_remove(intel_lpss_debugfs);
> +}
> +module_exit(intel_lpss_exit);
> +
> +MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
> +MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
> +MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
> +MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
> +MODULE_DESCRIPTION("Intel LPSS core driver");
> +MODULE_LICENSE("GPL v2");
> diff --git a/drivers/mfd/intel-lpss.h b/drivers/mfd/intel-lpss.h
> new file mode 100644
> index 0000000..f28cb28a
> --- /dev/null
> +++ b/drivers/mfd/intel-lpss.h
> @@ -0,0 +1,62 @@
> +/*
> + * Intel LPSS core support.
> + *
> + * Copyright (C) 2015, Intel Corporation
> + *
> + * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> + *          Mika Westerberg <mika.westerberg@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef __MFD_INTEL_LPSS_H
> +#define __MFD_INTEL_LPSS_H
> +
> +struct device;
> +struct resource;
> +
> +struct intel_lpss_platform_info {
> +	struct resource *mem;
> +	int irq;
> +	unsigned long clk_rate;
> +	const char *clk_con_id;
> +};
> +
> +int intel_lpss_probe(struct device *dev,
> +		     const struct intel_lpss_platform_info *info);
> +void intel_lpss_remove(struct device *dev);
> +
> +#ifdef CONFIG_PM
> +int intel_lpss_prepare(struct device *dev);
> +int intel_lpss_suspend(struct device *dev);
> +int intel_lpss_resume(struct device *dev);
> +
> +#ifdef CONFIG_PM_SLEEP
> +#define INTEL_LPSS_SLEEP_PM_OPS			\
> +	.prepare = intel_lpss_prepare,		\
> +	.suspend = intel_lpss_suspend,		\
> +	.resume = intel_lpss_resume,		\
> +	.freeze = intel_lpss_suspend,		\
> +	.thaw = intel_lpss_resume,		\
> +	.poweroff = intel_lpss_suspend,		\
> +	.restore = intel_lpss_resume,
> +#endif
> +
> +#define INTEL_LPSS_RUNTIME_PM_OPS		\
> +	.runtime_suspend = intel_lpss_suspend,	\
> +	.runtime_resume = intel_lpss_resume,
> +
> +#else /* !CONFIG_PM */
> +#define INTEL_LPSS_SLEEP_PM_OPS
> +#define INTEL_LPSS_RUNTIME_PM_OPS
> +#endif /* CONFIG_PM */
> +
> +#define INTEL_LPSS_PM_OPS(name)			\
> +const struct dev_pm_ops name = {		\
> +	INTEL_LPSS_SLEEP_PM_OPS			\
> +	INTEL_LPSS_RUNTIME_PM_OPS		\
> +}
> +
> +#endif /* __MFD_INTEL_LPSS_H */
Michael Turquette July 29, 2015, 10:44 p.m. UTC | #2
Hi Andy,

Is there a data sheet or reference manual publicly available for the
LPSS?

Quoting Andy Shevchenko (2015-07-27 08:04:03)
> diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
> new file mode 100644
> index 0000000..fdf4d5c
> --- /dev/null
> +++ b/drivers/mfd/intel-lpss.c
> @@ -0,0 +1,524 @@
> +/*
> + * Intel Sunrisepoint LPSS core support.
> + *
> + * Copyright (C) 2015, Intel Corporation
> + *
> + * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> + *          Mika Westerberg <mika.westerberg@linux.intel.com>
> + *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
> + *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clkdev.h>

I hope that we can get rid of the above two headers. See more below.

> +struct intel_lpss {
> +       const struct intel_lpss_platform_info *info;
> +       enum intel_lpss_dev_type type;
> +       struct clk *clk;
> +       struct clk_lookup *clock;

Same here. I don't see a use for the clk_lookup?

> +static void intel_lpss_unregister_clock_tree(struct clk *clk)
> +{
> +       struct clk *parent;
> +
> +       while (clk) {
> +               parent = clk_get_parent(clk);
> +               clk_unregister(clk);
> +               clk = parent;
> +       }

clk_unregister is for clock provider drivers that might be unloaded at
run-time, so it is nice of you to support it. However this
implementation isn't fully safe.

For instance, what happens if one day you plug in another clock provider
on top of this one? Your root clock here no longer be a root clock; it
would have a parent, and possibly a whole tree of clocks up above. If
the above happens then you'll unregister all of the parents up until you
hit a root clock!

A better alternative is for your clock provider driver (i.e. _this_
driver) to keep track of which clocks its registers and then unregister
them later.

In fact we have a nice function to help with that: devm_clk_register!
There are plenty of examples of how that is used. It doesn't work with
the "basic" clock types you are using here, but I'm not convinced that
you should be using those anyways...

> +}
> +
> +static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
> +                                            const char *devname,
> +                                            struct clk **clk)
> +{
> +       char name[32];
> +       struct clk *tmp = *clk;
> +
> +       snprintf(name, sizeof(name), "%s-enable", devname);
> +       tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
> +                               lpss->priv, 0, 0, NULL);
> +       if (IS_ERR(tmp))
> +               return PTR_ERR(tmp);
> +
> +       snprintf(name, sizeof(name), "%s-div", devname);
> +       tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
> +                                             0, lpss->priv, 1, 15, 16, 15, 0,
> +                                             NULL);
> +       if (IS_ERR(tmp))
> +               return PTR_ERR(tmp);
> +       *clk = tmp;
> +
> +       snprintf(name, sizeof(name), "%s-update", devname);
> +       tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
> +                               CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);

A gate, then a fixed divider, and then another gate? Seems weird. Do you
have other clock signals that are not enumerated here?

Where did those clock names come from? Are they like that in the data
sheet or just made up for the sake of writing this driver?

Why are the names generated dynamically? Some static data might be
better here. Do you anticipate having more than one LPSS in a running
system? I really hate __clk_get_name and would like to remove it some
day. If we can avoid using it here then I would be grateful.

Also, why do you register these clocks with clkdev? Do other drivers
clk_get them? When are the gates ever enabled/disabled?

> +       if (IS_ERR(tmp))
> +               return PTR_ERR(tmp);
> +       *clk = tmp;
> +
> +       return 0;
> +}
> +
> +static int intel_lpss_register_clock(struct intel_lpss *lpss)
> +{
> +       const struct mfd_cell *cell = lpss->cell;
> +       struct clk *clk;
> +       char devname[24];
> +       int ret;
> +
> +       if (!lpss->info->clk_rate)
> +               return 0;
> +
> +       /* Root clock */
> +       clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL,
> +                                     CLK_IS_ROOT, lpss->info->clk_rate);
> +       if (IS_ERR(clk))
> +               return PTR_ERR(clk);
> +
> +       snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
> +
> +       /*
> +        * Support for clock divider only if it has some preset value.
> +        * Otherwise we assume that the divider is not used.
> +        */
> +       if (lpss->type != LPSS_DEV_I2C) {
> +               ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
> +               if (ret)
> +                       goto err_clk_register;
> +       }

Do ACPI tables encode any meaningful data about clock signals? I gave
some advice on this topic a couple of years ago to folks hacking on ACPI
stuff in Linux, but I haven't kept up with the topic.

By comparison, most ARM-based platforms use Devicetree to link up a
clock provider to a clock consumer. I do not think similar
infrastructure exists yet for ACPI-based designs, but I wonder if the
clock data exists in newer ACPI tables to at least make it possible?

Regards,
Mike
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Rafael J. Wysocki July 29, 2015, 11:30 p.m. UTC | #3
On Wednesday, July 29, 2015 03:44:34 PM Michael Turquette wrote:
> Hi Andy,

[cut]

> Do ACPI tables encode any meaningful data about clock signals? I gave
> some advice on this topic a couple of years ago to folks hacking on ACPI
> stuff in Linux, but I haven't kept up with the topic.
> 
> By comparison, most ARM-based platforms use Devicetree to link up a
> clock provider to a clock consumer. I do not think similar
> infrastructure exists yet for ACPI-based designs, but I wonder if the
> clock data exists in newer ACPI tables to at least make it possible?

No, it doesn't.

Thanks,
Rafael

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Andy Shevchenko July 30, 2015, 10:19 a.m. UTC | #4
On Wed, 2015-07-29 at 15:44 -0700, Michael Turquette wrote:
> Hi Andy,
> 
> Is there a data sheet or reference manual publicly available for the
> LPSS?

Yes, I mentioned it in cover letter. For your convenience I just
copy'n'paste it here:

https://download.01.org/future-platform-configuration
-hub/skylake/register-definitions/332219-002.pdf


> 
> Quoting Andy Shevchenko (2015-07-27 08:04:03)
> > diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
> > new file mode 100644
> > index 0000000..fdf4d5c
> > --- /dev/null
> > +++ b/drivers/mfd/intel-lpss.c
> > @@ -0,0 +1,524 @@
> > +/*
> > + * Intel Sunrisepoint LPSS core support.
> > + *
> > + * Copyright (C) 2015, Intel Corporation
> > + *
> > + * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > + *          Mika Westerberg <mika.westerberg@linux.intel.com>
> > + *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > + *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
> > + *
> > + * This program is free software; you can redistribute it and/or 
> > modify
> > + * it under the terms of the GNU General Public License version 2 
> > as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/clkdev.h>
> 
> I hope that we can get rid of the above two headers. See more below.
> 
> > +struct intel_lpss {
> > +       const struct intel_lpss_platform_info *info;
> > +       enum intel_lpss_dev_type type;
> > +       struct clk *clk;
> > +       struct clk_lookup *clock;
> 
> Same here. I don't see a use for the clk_lookup?

clkdev_create() returns it.

> 
> > +static void intel_lpss_unregister_clock_tree(struct clk *clk)
> > +{
> > +       struct clk *parent;
> > +
> > +       while (clk) {
> > +               parent = clk_get_parent(clk);
> > +               clk_unregister(clk);
> > +               clk = parent;
> > +       }
> 
> clk_unregister is for clock provider drivers that might be unloaded 
> at
> run-time, so it is nice of you to support it. However this
> implementation isn't fully safe.
> 
> For instance, what happens if one day you plug in another clock 
> provider
> on top of this one? Your root clock here no longer be a root clock; 
> it
> would have a parent, and possibly a whole tree of clocks up above. If
> the above happens then you'll unregister all of the parents up until 
> you
> hit a root clock!
> 
> A better alternative is for your clock provider driver (i.e. _this_
> driver) to keep track of which clocks its registers and then 
> unregister
> them later.
> 
> In fact we have a nice function to help with that: devm_clk_register!
> 

I will look at this.

> There are plenty of examples of how that is used. It doesn't work 
> with
> the "basic" clock types you are using here, but I'm not convinced 
> that
> you should be using those anyways...
> 
> > +}
> > +
> > +static int intel_lpss_register_clock_divider(struct intel_lpss 
> > *lpss,
> > +                                            const char *devname,
> > +                                            struct clk **clk)
> > +{
> > +       char name[32];
> > +       struct clk *tmp = *clk;
> > +
> > +       snprintf(name, sizeof(name), "%s-enable", devname);
> > +       tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
> > +                               lpss->priv, 0, 0, NULL);
> > +       if (IS_ERR(tmp))
> > +               return PTR_ERR(tmp);
> > +
> > +       snprintf(name, sizeof(name), "%s-div", devname);
> > +       tmp = clk_register_fractional_divider(NULL, name, 
> > __clk_get_name(tmp),
> > +                                             0, lpss->priv, 1, 15, 
> > 16, 15, 0,
> > +                                             NULL);
> > +       if (IS_ERR(tmp))
> > +               return PTR_ERR(tmp);
> > +       *clk = tmp;
> > +
> > +       snprintf(name, sizeof(name), "%s-update", devname);
> > +       tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
> > +                               CLK_SET_RATE_PARENT, lpss->priv, 
> > 31, 0, NULL);
> 
> A gate, then a fixed divider, and then another gate? Seems weird. Do 
> you
> have other clock signals that are not enumerated here?
> 
> Where did those clock names come from? Are they like that in the data
> sheet or just made up for the sake of writing this driver?

For example, chapter 1.0, section 1.1 describes clock gating and
fractional divider for UART. Also the high bit updates the actual
divider after we supply m and n values.

Since we have the clock implementation which enables one bit per device
we have to do this in a way of clock tree.

If you have any better suggestion we would improve our driver.

> 
> Why are the names generated dynamically? Some static data might be
> better here. Do you anticipate having more than one LPSS in a running
> system? 

What do you mean under LPSS? We mean the entire IP block consists of
several devices (we only can say which and in what configuration
dynamically). devname here corresponds to the each device in the LPSS
IP block.

As an example
   clock                         enable_cnt  prepare_cnt        rate  
 accuracy   phase
-----------------------------------------------------------------------
-----------------
 0000:00:1e.3                             0            0   120000000   
       0 0  
    pxa2xx-spi.6-enable                   0            0   120000000   
       0 0  
       pxa2xx-spi.6-div                   0            0   120000000   
       0 0  
          pxa2xx-spi.6-update             0            0   120000000   
       0 0  
 0000:00:1e.0                             0            0   120000000   
       0 0  
    dw-apb-uart.5-enable                  0            0   120000000   
       0 0  
       dw-apb-uart.5-div                  0            0     1843200   
       0 0  
          dw-apb-uart.5-update            0            0     1843200   
       0 0  
 0000:00:19.0                             0            0   120000000   
       0 0  
    dw-apb-uart.4-enable                  0            0   120000000   
       0 0  
       dw-apb-uart.4-div                  0            0     1843200   
       0 0  
          dw-apb-uart.4-update            0            0     1843200   
       0 0  

> I really hate __clk_get_name and would like to remove it some
> day. If we can avoid using it here then I would be grateful.
> 
> Also, why do you register these clocks with clkdev? Do other drivers
> clk_get them?

Yes. The actual consumers do that: spi-pxa2xx, 8250_dw, i2c-designware.

>  When are the gates ever enabled/disabled?

In the mentioned drivers. For example, for UART is a clock called
'baudclk' which is changed whenever user changes a baud rate.
diff mbox

Patch

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 6538159..268b6dd 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -328,6 +328,29 @@  config INTEL_SOC_PMIC
 	  thermal, charger and related power management functions
 	  on these systems.
 
+config MFD_INTEL_LPSS
+	tristate
+	select COMMON_CLK
+	select MFD_CORE
+
+config MFD_INTEL_LPSS_ACPI
+	tristate "Intel Low Power Subsystem support in ACPI mode"
+	select MFD_INTEL_LPSS
+	depends on X86 && ACPI
+	help
+	  This driver supports Intel Low Power Subsystem (LPSS) devices such as
+	  I2C, SPI and HS-UART starting from Intel Sunrisepoint (Intel Skylake
+	  PCH) in ACPI mode.
+
+config MFD_INTEL_LPSS_PCI
+	tristate "Intel Low Power Subsystem support in PCI mode"
+	select MFD_INTEL_LPSS
+	depends on X86 && PCI
+	help
+	  This driver supports Intel Low Power Subsystem (LPSS) devices such as
+	  I2C, SPI and HS-UART starting from Intel Sunrisepoint (Intel Skylake
+	  PCH) in PCI mode.
+
 config MFD_INTEL_MSIC
 	bool "Intel MSIC"
 	depends on INTEL_SCU_IPC
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index ea40e07..9d730a2 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -161,6 +161,9 @@  obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
 obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
 obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
 obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
+obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
+obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
+obj-$(CONFIG_MFD_INTEL_LPSS_ACPI)	+= intel-lpss-acpi.o
 obj-$(CONFIG_MFD_INTEL_MSIC)	+= intel_msic.o
 obj-$(CONFIG_MFD_PALMAS)	+= palmas.o
 obj-$(CONFIG_MFD_VIPERBOARD)    += viperboard.o
diff --git a/drivers/mfd/intel-lpss-acpi.c b/drivers/mfd/intel-lpss-acpi.c
new file mode 100644
index 0000000..0d92d73
--- /dev/null
+++ b/drivers/mfd/intel-lpss-acpi.c
@@ -0,0 +1,84 @@ 
+/*
+ * Intel LPSS ACPI support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *          Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
+
+#include "intel-lpss.h"
+
+static const struct intel_lpss_platform_info spt_info = {
+	.clk_rate = 120000000,
+};
+
+static const struct acpi_device_id intel_lpss_acpi_ids[] = {
+	/* SPT */
+	{ "INT3446", (kernel_ulong_t)&spt_info },
+	{ "INT3447", (kernel_ulong_t)&spt_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, intel_lpss_acpi_ids);
+
+static int intel_lpss_acpi_probe(struct platform_device *pdev)
+{
+	struct intel_lpss_platform_info *info;
+	const struct acpi_device_id *id;
+
+	id = acpi_match_device(intel_lpss_acpi_ids, &pdev->dev);
+	if (!id)
+		return -ENODEV;
+
+	info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	info->irq = platform_get_irq(pdev, 0);
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+
+	return intel_lpss_probe(&pdev->dev, info);
+}
+
+static int intel_lpss_acpi_remove(struct platform_device *pdev)
+{
+	intel_lpss_remove(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static INTEL_LPSS_PM_OPS(intel_lpss_acpi_pm_ops);
+
+static struct platform_driver intel_lpss_acpi_driver = {
+	.probe = intel_lpss_acpi_probe,
+	.remove = intel_lpss_acpi_remove,
+	.driver = {
+		.name = "intel-lpss",
+		.acpi_match_table = intel_lpss_acpi_ids,
+		.pm = &intel_lpss_acpi_pm_ops,
+	},
+};
+
+module_platform_driver(intel_lpss_acpi_driver);
+
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_DESCRIPTION("Intel LPSS ACPI driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mfd/intel-lpss-pci.c b/drivers/mfd/intel-lpss-pci.c
new file mode 100644
index 0000000..9236dff
--- /dev/null
+++ b/drivers/mfd/intel-lpss-pci.c
@@ -0,0 +1,113 @@ 
+/*
+ * Intel LPSS PCI support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *          Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+
+#include "intel-lpss.h"
+
+static int intel_lpss_pci_probe(struct pci_dev *pdev,
+				const struct pci_device_id *id)
+{
+	struct intel_lpss_platform_info *info;
+	int ret;
+
+	ret = pcim_enable_device(pdev);
+	if (ret)
+		return ret;
+
+	info = devm_kmemdup(&pdev->dev, (void *)id->driver_data, sizeof(*info),
+			    GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	info->mem = &pdev->resource[0];
+	info->irq = pdev->irq;
+
+	/* Probably it is enough to set this for iDMA capable devices only */
+	pci_set_master(pdev);
+
+	ret = intel_lpss_probe(&pdev->dev, info);
+	if (ret)
+		return ret;
+
+	pm_runtime_put(&pdev->dev);
+	pm_runtime_allow(&pdev->dev);
+
+	return 0;
+}
+
+static void intel_lpss_pci_remove(struct pci_dev *pdev)
+{
+	pm_runtime_forbid(&pdev->dev);
+	pm_runtime_get_sync(&pdev->dev);
+
+	intel_lpss_remove(&pdev->dev);
+}
+
+static INTEL_LPSS_PM_OPS(intel_lpss_pci_pm_ops);
+
+static const struct intel_lpss_platform_info spt_info = {
+	.clk_rate = 120000000,
+};
+
+static const struct intel_lpss_platform_info spt_uart_info = {
+	.clk_rate = 120000000,
+	.clk_con_id = "baudclk",
+};
+
+static const struct pci_device_id intel_lpss_pci_ids[] = {
+	/* SPT-LP */
+	{ PCI_VDEVICE(INTEL, 0x9d27), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0x9d28), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0x9d29), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d2a), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d60), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d61), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d62), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d63), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d64), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d65), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0x9d66), (kernel_ulong_t)&spt_uart_info },
+	/* SPT-H */
+	{ PCI_VDEVICE(INTEL, 0xa127), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0xa128), (kernel_ulong_t)&spt_uart_info },
+	{ PCI_VDEVICE(INTEL, 0xa129), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa12a), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa160), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa161), (kernel_ulong_t)&spt_info },
+	{ PCI_VDEVICE(INTEL, 0xa166), (kernel_ulong_t)&spt_uart_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, intel_lpss_pci_ids);
+
+static struct pci_driver intel_lpss_pci_driver = {
+	.name = "intel-lpss",
+	.id_table = intel_lpss_pci_ids,
+	.probe = intel_lpss_pci_probe,
+	.remove = intel_lpss_pci_remove,
+	.driver = {
+		.pm = &intel_lpss_pci_pm_ops,
+	},
+};
+
+module_pci_driver(intel_lpss_pci_driver);
+
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_DESCRIPTION("Intel LPSS PCI driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c
new file mode 100644
index 0000000..fdf4d5c
--- /dev/null
+++ b/drivers/mfd/intel-lpss.c
@@ -0,0 +1,524 @@ 
+/*
+ * Intel Sunrisepoint LPSS core support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *          Mika Westerberg <mika.westerberg@linux.intel.com>
+ *          Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *          Jarkko Nikula <jarkko.nikula@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/debugfs.h>
+#include <linux/idr.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/pm_qos.h>
+#include <linux/pm_runtime.h>
+#include <linux/seq_file.h>
+
+#include "intel-lpss.h"
+
+#define LPSS_DEV_OFFSET		0x000
+#define LPSS_DEV_SIZE		0x200
+#define LPSS_PRIV_OFFSET	0x200
+#define LPSS_PRIV_SIZE		0x100
+#define LPSS_IDMA64_OFFSET	0x800
+#define LPSS_IDMA64_SIZE	0x800
+
+/* Offsets from lpss->priv */
+#define LPSS_PRIV_RESETS		0x04
+#define LPSS_PRIV_RESETS_FUNC		BIT(2)
+#define LPSS_PRIV_RESETS_IDMA		0x3
+
+#define LPSS_PRIV_ACTIVELTR		0x10
+#define LPSS_PRIV_IDLELTR		0x14
+
+#define LPSS_PRIV_LTR_REQ		BIT(15)
+#define LPSS_PRIV_LTR_SCALE_MASK	0xc00
+#define LPSS_PRIV_LTR_SCALE_1US		0x800
+#define LPSS_PRIV_LTR_SCALE_32US	0xc00
+#define LPSS_PRIV_LTR_VALUE_MASK	0x3ff
+
+#define LPSS_PRIV_SSP_REG		0x20
+#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN	BIT(0)
+
+#define LPSS_PRIV_REMAP_ADDR_LO		0x40
+#define LPSS_PRIV_REMAP_ADDR_HI		0x44
+
+#define LPSS_PRIV_CAPS			0xfc
+#define LPSS_PRIV_CAPS_NO_IDMA		BIT(8)
+#define LPSS_PRIV_CAPS_TYPE_SHIFT	4
+#define LPSS_PRIV_CAPS_TYPE_MASK	(0xf << LPSS_PRIV_CAPS_TYPE_SHIFT)
+
+/* This matches the type field in CAPS register */
+enum intel_lpss_dev_type {
+	LPSS_DEV_I2C = 0,
+	LPSS_DEV_UART,
+	LPSS_DEV_SPI,
+};
+
+struct intel_lpss {
+	const struct intel_lpss_platform_info *info;
+	enum intel_lpss_dev_type type;
+	struct clk *clk;
+	struct clk_lookup *clock;
+	const struct mfd_cell *cell;
+	struct device *dev;
+	void __iomem *priv;
+	int devid;
+	u32 caps;
+	u32 active_ltr;
+	u32 idle_ltr;
+	struct dentry *debugfs;
+};
+
+static const struct resource intel_lpss_dev_resources[] = {
+	DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"),
+	DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"),
+	DEFINE_RES_IRQ(0),
+};
+
+static const struct resource intel_lpss_idma64_resources[] = {
+	DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE),
+	DEFINE_RES_IRQ(0),
+};
+
+#define LPSS_IDMA64_DRIVER_NAME		"idma64"
+
+/*
+ * Cells needs to be ordered so that the iDMA is created first. This is
+ * because we need to be sure the DMA is available when the host controller
+ * driver is probed.
+ */
+static const struct mfd_cell intel_lpss_idma64_cell = {
+	.name = LPSS_IDMA64_DRIVER_NAME,
+	.num_resources = ARRAY_SIZE(intel_lpss_idma64_resources),
+	.resources = intel_lpss_idma64_resources,
+};
+
+static const struct mfd_cell intel_lpss_i2c_cell = {
+	.name = "i2c_designware",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static const struct mfd_cell intel_lpss_uart_cell = {
+	.name = "dw-apb-uart",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static const struct mfd_cell intel_lpss_spi_cell = {
+	.name = "pxa2xx-spi",
+	.num_resources = ARRAY_SIZE(intel_lpss_dev_resources),
+	.resources = intel_lpss_dev_resources,
+};
+
+static DEFINE_IDA(intel_lpss_devid_ida);
+static struct dentry *intel_lpss_debugfs;
+
+static int intel_lpss_request_dma_module(const char *name)
+{
+	static bool intel_lpss_dma_requested;
+
+	if (intel_lpss_dma_requested)
+		return 0;
+
+	intel_lpss_dma_requested = true;
+	return request_module("%s", name);
+}
+
+static void intel_lpss_cache_ltr(struct intel_lpss *lpss)
+{
+	lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
+	lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR);
+}
+
+static int intel_lpss_debugfs_add(struct intel_lpss *lpss)
+{
+	struct dentry *dir;
+
+	dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
+
+	/* Cache the values into lpss structure */
+	intel_lpss_cache_ltr(lpss);
+
+	debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps);
+	debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr);
+	debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr);
+
+	lpss->debugfs = dir;
+	return 0;
+}
+
+static void intel_lpss_debugfs_remove(struct intel_lpss *lpss)
+{
+	debugfs_remove_recursive(lpss->debugfs);
+}
+
+static void intel_lpss_ltr_set(struct device *dev, s32 val)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+	u32 ltr;
+
+	/*
+	 * Program latency tolerance (LTR) accordingly what has been asked
+	 * by the PM QoS layer or disable it in case we were passed
+	 * negative value or PM_QOS_LATENCY_ANY.
+	 */
+	ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR);
+
+	if (val == PM_QOS_LATENCY_ANY || val < 0) {
+		ltr &= ~LPSS_PRIV_LTR_REQ;
+	} else {
+		ltr |= LPSS_PRIV_LTR_REQ;
+		ltr &= ~LPSS_PRIV_LTR_SCALE_MASK;
+		ltr &= ~LPSS_PRIV_LTR_VALUE_MASK;
+
+		if (val > LPSS_PRIV_LTR_VALUE_MASK)
+			ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5;
+		else
+			ltr |= LPSS_PRIV_LTR_SCALE_1US | val;
+	}
+
+	if (ltr == lpss->active_ltr)
+		return;
+
+	writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR);
+	writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR);
+
+	/* Cache the values into lpss structure */
+	intel_lpss_cache_ltr(lpss);
+}
+
+static void intel_lpss_ltr_expose(struct intel_lpss *lpss)
+{
+	lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set;
+	dev_pm_qos_expose_latency_tolerance(lpss->dev);
+}
+
+static void intel_lpss_ltr_hide(struct intel_lpss *lpss)
+{
+	dev_pm_qos_hide_latency_tolerance(lpss->dev);
+	lpss->dev->power.set_latency_tolerance = NULL;
+}
+
+static int intel_lpss_assign_devs(struct intel_lpss *lpss)
+{
+	unsigned int type;
+
+	type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
+	type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
+
+	switch (type) {
+	case LPSS_DEV_I2C:
+		lpss->cell = &intel_lpss_i2c_cell;
+		break;
+	case LPSS_DEV_UART:
+		lpss->cell = &intel_lpss_uart_cell;
+		break;
+	case LPSS_DEV_SPI:
+		lpss->cell = &intel_lpss_spi_cell;
+		break;
+	default:
+		return -ENODEV;
+	}
+
+	lpss->type = type;
+
+	return 0;
+}
+
+static bool intel_lpss_has_idma(const struct intel_lpss *lpss)
+{
+	return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0;
+}
+
+static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss)
+{
+	resource_size_t addr = lpss->info->mem->start;
+
+	writel(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR_LO);
+#if BITS_PER_LONG > 32
+	writel(addr >> 32, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
+#else
+	writel(0, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI);
+#endif
+}
+
+static void intel_lpss_deassert_reset(const struct intel_lpss *lpss)
+{
+	u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA;
+
+	/* Bring out the device from reset */
+	writel(value, lpss->priv + LPSS_PRIV_RESETS);
+}
+
+static void intel_lpss_init_dev(const struct intel_lpss *lpss)
+{
+	u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN;
+
+	intel_lpss_deassert_reset(lpss);
+
+	if (!intel_lpss_has_idma(lpss))
+		return;
+
+	intel_lpss_set_remap_addr(lpss);
+
+	/* Make sure that SPI multiblock DMA transfers are re-enabled */
+	if (lpss->type == LPSS_DEV_SPI)
+		writel(value, lpss->priv + LPSS_PRIV_SSP_REG);
+}
+
+static void intel_lpss_unregister_clock_tree(struct clk *clk)
+{
+	struct clk *parent;
+
+	while (clk) {
+		parent = clk_get_parent(clk);
+		clk_unregister(clk);
+		clk = parent;
+	}
+}
+
+static int intel_lpss_register_clock_divider(struct intel_lpss *lpss,
+					     const char *devname,
+					     struct clk **clk)
+{
+	char name[32];
+	struct clk *tmp = *clk;
+
+	snprintf(name, sizeof(name), "%s-enable", devname);
+	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0,
+				lpss->priv, 0, 0, NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+
+	snprintf(name, sizeof(name), "%s-div", devname);
+	tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp),
+					      0, lpss->priv, 1, 15, 16, 15, 0,
+					      NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	*clk = tmp;
+
+	snprintf(name, sizeof(name), "%s-update", devname);
+	tmp = clk_register_gate(NULL, name, __clk_get_name(tmp),
+				CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL);
+	if (IS_ERR(tmp))
+		return PTR_ERR(tmp);
+	*clk = tmp;
+
+	return 0;
+}
+
+static int intel_lpss_register_clock(struct intel_lpss *lpss)
+{
+	const struct mfd_cell *cell = lpss->cell;
+	struct clk *clk;
+	char devname[24];
+	int ret;
+
+	if (!lpss->info->clk_rate)
+		return 0;
+
+	/* Root clock */
+	clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL,
+				      CLK_IS_ROOT, lpss->info->clk_rate);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid);
+
+	/*
+	 * Support for clock divider only if it has some preset value.
+	 * Otherwise we assume that the divider is not used.
+	 */
+	if (lpss->type != LPSS_DEV_I2C) {
+		ret = intel_lpss_register_clock_divider(lpss, devname, &clk);
+		if (ret)
+			goto err_clk_register;
+	}
+
+	ret = -ENOMEM;
+
+	/* Clock for the host controller */
+	lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname);
+	if (!lpss->clock)
+		goto err_clk_register;
+
+	lpss->clk = clk;
+
+	return 0;
+
+err_clk_register:
+	intel_lpss_unregister_clock_tree(clk);
+
+	return ret;
+}
+
+static void intel_lpss_unregister_clock(struct intel_lpss *lpss)
+{
+	if (IS_ERR_OR_NULL(lpss->clk))
+		return;
+
+	clkdev_drop(lpss->clock);
+	intel_lpss_unregister_clock_tree(lpss->clk);
+}
+
+int intel_lpss_probe(struct device *dev,
+		     const struct intel_lpss_platform_info *info)
+{
+	struct intel_lpss *lpss;
+	int ret;
+
+	if (!info || !info->mem || info->irq <= 0)
+		return -EINVAL;
+
+	lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL);
+	if (!lpss)
+		return -ENOMEM;
+
+	lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET,
+				  LPSS_PRIV_SIZE);
+	if (!lpss->priv)
+		return -ENOMEM;
+
+	lpss->info = info;
+	lpss->dev = dev;
+	lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS);
+
+	dev_set_drvdata(dev, lpss);
+
+	ret = intel_lpss_assign_devs(lpss);
+	if (ret)
+		return ret;
+
+	intel_lpss_init_dev(lpss);
+
+	lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL);
+	if (lpss->devid < 0)
+		return lpss->devid;
+
+	ret = intel_lpss_register_clock(lpss);
+	if (ret)
+		goto err_clk_register;
+
+	intel_lpss_ltr_expose(lpss);
+
+	ret = intel_lpss_debugfs_add(lpss);
+	if (ret)
+		dev_warn(dev, "Failed to create debugfs entries\n");
+
+	if (intel_lpss_has_idma(lpss)) {
+		/*
+		 * Ensure the DMA driver is loaded before the host
+		 * controller device appears, so that the host controller
+		 * driver can request its DMA channels as early as
+		 * possible.
+		 *
+		 * If the DMA module is not there that's OK as well.
+		 */
+		intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME);
+
+		ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell,
+				      1, info->mem, info->irq, NULL);
+		if (ret)
+			dev_warn(dev, "Failed to add %s, fallback to PIO\n",
+				 LPSS_IDMA64_DRIVER_NAME);
+	}
+
+	ret = mfd_add_devices(dev, lpss->devid, lpss->cell,
+			      1, info->mem, info->irq, NULL);
+	if (ret)
+		goto err_remove_ltr;
+
+	return 0;
+
+err_remove_ltr:
+	intel_lpss_debugfs_remove(lpss);
+	intel_lpss_ltr_hide(lpss);
+
+err_clk_register:
+	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_probe);
+
+void intel_lpss_remove(struct device *dev)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+
+	mfd_remove_devices(dev);
+	intel_lpss_debugfs_remove(lpss);
+	intel_lpss_ltr_hide(lpss);
+	intel_lpss_unregister_clock(lpss);
+	ida_simple_remove(&intel_lpss_devid_ida, lpss->devid);
+}
+EXPORT_SYMBOL_GPL(intel_lpss_remove);
+
+static int resume_lpss_device(struct device *dev, void *data)
+{
+	pm_runtime_resume(dev);
+	return 0;
+}
+
+int intel_lpss_prepare(struct device *dev)
+{
+	/*
+	 * Resume both child devices before entering system sleep. This
+	 * ensures that they are in proper state before they get suspended.
+	 */
+	device_for_each_child_reverse(dev, NULL, resume_lpss_device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_prepare);
+
+int intel_lpss_suspend(struct device *dev)
+{
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_suspend);
+
+int intel_lpss_resume(struct device *dev)
+{
+	struct intel_lpss *lpss = dev_get_drvdata(dev);
+
+	intel_lpss_init_dev(lpss);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(intel_lpss_resume);
+
+static int __init intel_lpss_init(void)
+{
+	intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL);
+	return 0;
+}
+module_init(intel_lpss_init);
+
+static void __exit intel_lpss_exit(void)
+{
+	debugfs_remove(intel_lpss_debugfs);
+}
+module_exit(intel_lpss_exit);
+
+MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
+MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>");
+MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
+MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>");
+MODULE_DESCRIPTION("Intel LPSS core driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mfd/intel-lpss.h b/drivers/mfd/intel-lpss.h
new file mode 100644
index 0000000..f28cb28a
--- /dev/null
+++ b/drivers/mfd/intel-lpss.h
@@ -0,0 +1,62 @@ 
+/*
+ * Intel LPSS core support.
+ *
+ * Copyright (C) 2015, Intel Corporation
+ *
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *          Mika Westerberg <mika.westerberg@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef __MFD_INTEL_LPSS_H
+#define __MFD_INTEL_LPSS_H
+
+struct device;
+struct resource;
+
+struct intel_lpss_platform_info {
+	struct resource *mem;
+	int irq;
+	unsigned long clk_rate;
+	const char *clk_con_id;
+};
+
+int intel_lpss_probe(struct device *dev,
+		     const struct intel_lpss_platform_info *info);
+void intel_lpss_remove(struct device *dev);
+
+#ifdef CONFIG_PM
+int intel_lpss_prepare(struct device *dev);
+int intel_lpss_suspend(struct device *dev);
+int intel_lpss_resume(struct device *dev);
+
+#ifdef CONFIG_PM_SLEEP
+#define INTEL_LPSS_SLEEP_PM_OPS			\
+	.prepare = intel_lpss_prepare,		\
+	.suspend = intel_lpss_suspend,		\
+	.resume = intel_lpss_resume,		\
+	.freeze = intel_lpss_suspend,		\
+	.thaw = intel_lpss_resume,		\
+	.poweroff = intel_lpss_suspend,		\
+	.restore = intel_lpss_resume,
+#endif
+
+#define INTEL_LPSS_RUNTIME_PM_OPS		\
+	.runtime_suspend = intel_lpss_suspend,	\
+	.runtime_resume = intel_lpss_resume,
+
+#else /* !CONFIG_PM */
+#define INTEL_LPSS_SLEEP_PM_OPS
+#define INTEL_LPSS_RUNTIME_PM_OPS
+#endif /* CONFIG_PM */
+
+#define INTEL_LPSS_PM_OPS(name)			\
+const struct dev_pm_ops name = {		\
+	INTEL_LPSS_SLEEP_PM_OPS			\
+	INTEL_LPSS_RUNTIME_PM_OPS		\
+}
+
+#endif /* __MFD_INTEL_LPSS_H */