[13/17] clk: x86: Add Atom PMC platform clocks
diff mbox

Message ID 1471037280-17433-14-git-send-email-pierre-louis.bossart@linux.intel.com
State New
Headers show

Commit Message

Pierre-Louis Bossart Aug. 12, 2016, 9:27 p.m. UTC
From: Irina Tirdea <irina.tirdea@intel.com>

The Baytral and CherryTrail platforms provide platform clocks
through their Power Management Controller (PMC).

The SoC supports up to 6 clocks (PMC_PLT_CLK[5:0]) with a
frequency of either 19.2 MHz (PLL) or 25 MHz (XTAL).
These clocks are available for general system use, where appropriate
and each have Control & Frequency register fields associated with them.

For example, the usage for platform clocks could be:
  PLT_CLK[2:0] - Camera
  PLT_CLK[3] - Audio Codec
  PLT_CLK[4] -
  PLT_CLK[5] - COMMs

Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
 arch/x86/Kconfig                  |   1 +
 arch/x86/include/asm/pmc_atom.h   |   6 +
 arch/x86/platform/atom/pmc_atom.c |  55 ++++-
 drivers/clk/x86/Makefile          |   1 +
 drivers/clk/x86/clk-byt-plt.c     | 413 ++++++++++++++++++++++++++++++++++++++
 5 files changed, 473 insertions(+), 3 deletions(-)
 create mode 100644 drivers/clk/x86/clk-byt-plt.c

Patch
diff mbox

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5c6e747..781c417 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2743,6 +2743,7 @@  config X86_DMA_REMAP
 config PMC_ATOM
 	def_bool y
         depends on PCI
+	select COMMON_CLK
 
 config VMD
 	depends on PCI_MSI
diff --git a/arch/x86/include/asm/pmc_atom.h b/arch/x86/include/asm/pmc_atom.h
index aa8744c..59f9516 100644
--- a/arch/x86/include/asm/pmc_atom.h
+++ b/arch/x86/include/asm/pmc_atom.h
@@ -152,6 +152,12 @@ 
 #define	SLEEP_TYPE_S5		0x1C00
 #define	SLEEP_ENABLE		0x2000
 
+struct pmc_clk {
+	const char *name;
+	unsigned long freq;
+	const char *parent_name;
+};
+
 extern int pmc_atom_read(int offset, u32 *value);
 extern int pmc_atom_write(int offset, u32 value);
 
diff --git a/arch/x86/platform/atom/pmc_atom.c b/arch/x86/platform/atom/pmc_atom.c
index 964ff4f..e2de3e2 100644
--- a/arch/x86/platform/atom/pmc_atom.c
+++ b/arch/x86/platform/atom/pmc_atom.c
@@ -21,6 +21,7 @@ 
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
 #include <linux/io.h>
+#include <linux/platform_device.h>
 
 #include <asm/pmc_atom.h>
 
@@ -37,6 +38,11 @@  struct pmc_reg_map {
 	const struct pmc_bit_map *pss;
 };
 
+struct pmc_data {
+	const struct pmc_reg_map *map;
+	const struct pmc_clk *clks;
+};
+
 struct pmc_dev {
 	u32 base_addr;
 	void __iomem *regmap;
@@ -50,6 +56,29 @@  struct pmc_dev {
 static struct pmc_dev pmc_device;
 static u32 acpi_base_addr;
 
+static const struct pmc_clk byt_clks[] = {
+	{
+		.name = "xtal",
+		.freq = 25000000,
+		.parent_name = NULL,
+	},
+	{
+		.name = "pll",
+		.freq = 19200000,
+		.parent_name = "xtal",
+	},
+	{},
+};
+
+static const struct pmc_clk cht_clks[] = {
+	{
+		.name = "xtal",
+		.freq = 19200000,
+		.parent_name = NULL,
+	},
+	{},
+};
+
 static const struct pmc_bit_map d3_sts_0_map[] = {
 	{"LPSS1_F0_DMA",	BIT_LPSS1_F0_DMA},
 	{"LPSS1_F1_PWM1",	BIT_LPSS1_F1_PWM1},
@@ -169,6 +198,16 @@  static const struct pmc_reg_map cht_reg_map = {
 	.pss		= cht_pss_map,
 };
 
+static const struct pmc_data byt_data = {
+	.map = &byt_reg_map,
+	.clks = byt_clks,
+};
+
+static const struct pmc_data cht_data = {
+	.map = &cht_reg_map,
+	.clks = cht_clks,
+};
+
 static inline u32 pmc_reg_read(struct pmc_dev *pmc, int reg_offset)
 {
 	return readl(pmc->regmap + reg_offset);
@@ -384,8 +423,11 @@  static int pmc_dbgfs_register(struct pmc_dev *pmc)
 
 static int pmc_setup_dev(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
+	struct platform_device *clkdev;
 	struct pmc_dev *pmc = &pmc_device;
-	const struct pmc_reg_map *map = (struct pmc_reg_map *)ent->driver_data;
+	const struct pmc_data *data = (struct pmc_data *)ent->driver_data;
+	const struct pmc_reg_map *map = data->map;
+	const struct pmc_clk *clks = data->clks;
 	int ret;
 
 	/* Obtain ACPI base address */
@@ -414,6 +456,13 @@  static int pmc_setup_dev(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (ret)
 		dev_warn(&pdev->dev, "debugfs register failed\n");
 
+	/* Register platform clocks - PMC_PLT_CLK [5:0] */
+	clkdev = platform_device_register_data(NULL, "clk-byt-plt", -1,
+					       &clks, sizeof(clks));
+	if (IS_ERR(clkdev))
+		dev_warn(&pdev->dev, "platform clocks register failed: %ld\n",
+			 PTR_ERR(clkdev));
+
 	pmc->init = true;
 	return ret;
 }
@@ -424,8 +473,8 @@  static int pmc_setup_dev(struct pci_dev *pdev, const struct pci_device_id *ent)
  * used by pci_match_id() call below.
  */
 static const struct pci_device_id pmc_pci_ids[] = {
-	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_VLV_PMC), (kernel_ulong_t)&byt_reg_map },
-	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_CHT_PMC), (kernel_ulong_t)&cht_reg_map },
+	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_VLV_PMC), (kernel_ulong_t)&byt_data },
+	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_CHT_PMC), (kernel_ulong_t)&cht_data },
 	{ 0, },
 };
 
diff --git a/drivers/clk/x86/Makefile b/drivers/clk/x86/Makefile
index 0478138..cbdc8cc 100644
--- a/drivers/clk/x86/Makefile
+++ b/drivers/clk/x86/Makefile
@@ -1,2 +1,3 @@ 
 clk-x86-lpss-objs		:= clk-lpt.o
 obj-$(CONFIG_X86_INTEL_LPSS)	+= clk-x86-lpss.o
+obj-$(CONFIG_PMC_ATOM)		+= clk-byt-plt.o
diff --git a/drivers/clk/x86/clk-byt-plt.c b/drivers/clk/x86/clk-byt-plt.c
new file mode 100644
index 0000000..330cd35
--- /dev/null
+++ b/drivers/clk/x86/clk-byt-plt.c
@@ -0,0 +1,413 @@ 
+/*
+ * Intel Atom platform clocks driver for Baytrail and CherryTrail SoC.
+ *
+ * Copyright (C) 2016, Intel Corporation
+ * Author: Irina Tirdea <irina.tirdea@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/clkdev.h>
+
+#include <asm/pmc_atom.h>
+
+#define PLT_CLK_NAME_BASE	"pmc_plt_clk_"
+#define PLT_CLK_DRIVER_NAME	"clk-byt-plt"
+
+#define PMC_CLK_CTL_0		0x60
+#define PMC_CLK_CTL_SIZE	4
+#define PMC_CLK_NUM		6
+#define PMC_MASK_CLK_CTL	GENMASK(1, 0)
+#define PMC_MASK_CLK_FREQ	BIT(2)
+#define PMC_CLK_CTL_GATED_ON_D3	0x0
+#define PMC_CLK_CTL_FORCE_ON	0x1
+#define PMC_CLK_CTL_FORCE_OFF	0x2
+#define PMC_CLK_CTL_RESERVED	0x3
+#define PMC_CLK_FREQ_XTAL	0x0	/* 25 MHz */
+#define PMC_CLK_FREQ_PLL	0x4	/* 19.2 MHz */
+
+struct clk_plt_fixed {
+	struct clk *clk;
+	struct clk_lookup *lookup;
+};
+
+struct clk_plt {
+	struct clk_hw hw;
+	u8 id;
+	u32 offset;
+	struct clk_lookup *lookup;
+	spinlock_t lock;
+};
+
+#define to_clk_plt(_hw) container_of(_hw, struct clk_plt, hw)
+
+struct clk_plt_data {
+	struct clk_plt_fixed **parents;
+	u8 nparents;
+	struct clk *clks[PMC_CLK_NUM];
+};
+
+static inline int plt_reg_to_parent(int reg)
+{
+	switch (reg & PMC_MASK_CLK_FREQ) {
+	case PMC_CLK_FREQ_XTAL:
+		return 0;	/* index 0 in parents[] */
+	case PMC_CLK_FREQ_PLL:
+		return 1;	/* index 1 in parents[] */
+	}
+
+	return 0;
+}
+
+static inline int plt_parent_to_reg(int index)
+{
+	switch (index) {
+	case 0:	/* index 0 in parents[] */
+		return PMC_CLK_FREQ_XTAL;
+	case 1:	/* index 0 in parents[] */
+		return PMC_CLK_FREQ_PLL;
+	}
+
+	return PMC_CLK_FREQ_XTAL;
+}
+
+static inline int plt_reg_to_enabled(int reg)
+{
+	switch (reg & PMC_MASK_CLK_CTL) {
+	case PMC_CLK_CTL_GATED_ON_D3:
+	case PMC_CLK_CTL_FORCE_ON:
+		return 1;	/* enabled */
+	case PMC_CLK_CTL_FORCE_OFF:
+	case PMC_CLK_CTL_RESERVED:
+	default:
+		return 0;	/* disabled */
+	}
+}
+
+static int plt_pmc_atom_update(struct clk_plt *clk, u32 mask, u32 val)
+{
+	int ret;
+	u32 orig, tmp;
+	unsigned long flags = 0;
+
+	spin_lock_irqsave(&clk->lock, flags);
+
+	ret = pmc_atom_read(clk->offset, &orig);
+	if (ret)
+		goto out;
+
+	tmp = orig & ~mask;
+	tmp |= val & mask;
+
+	if (tmp == orig)
+		goto out;
+
+	ret = pmc_atom_write(clk->offset, tmp);
+	if (ret)
+		goto out;
+
+out:
+	spin_unlock_irqrestore(&clk->lock, flags);
+
+	return ret;
+}
+
+static int plt_clk_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_plt *clk = to_clk_plt(hw);
+
+	return plt_pmc_atom_update(clk, PMC_MASK_CLK_FREQ,
+				   plt_parent_to_reg(index));
+}
+
+static u8 plt_clk_get_parent(struct clk_hw *hw)
+{
+	struct clk_plt *clk = to_clk_plt(hw);
+	u32 value;
+	int ret;
+
+	ret = pmc_atom_read(clk->offset, &value);
+	if (ret)
+		return ret;
+
+	return plt_reg_to_parent(value);
+}
+
+static int plt_clk_enable(struct clk_hw *hw)
+{
+	struct clk_plt *clk = to_clk_plt(hw);
+
+	return plt_pmc_atom_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_ON);
+}
+
+static void plt_clk_disable(struct clk_hw *hw)
+{
+	struct clk_plt *clk = to_clk_plt(hw);
+
+	plt_pmc_atom_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_OFF);
+}
+
+static int plt_clk_is_enabled(struct clk_hw *hw)
+{
+	struct clk_plt *clk = to_clk_plt(hw);
+	u32 value;
+	int ret;
+
+	ret = pmc_atom_read(clk->offset, &value);
+	if (ret)
+		return ret;
+
+	return plt_reg_to_enabled(value);
+}
+
+static const struct clk_ops plt_clk_ops = {
+	.enable = plt_clk_enable,
+	.disable = plt_clk_disable,
+	.is_enabled = plt_clk_is_enabled,
+	.get_parent = plt_clk_get_parent,
+	.set_parent = plt_clk_set_parent,
+	.determine_rate = __clk_mux_determine_rate,
+};
+
+static struct clk *plt_clk_register(struct platform_device *pdev, int id,
+				    const char **parent_names, int num_parents)
+{
+	struct clk_plt *pclk;
+	struct clk *clk;
+	struct clk_init_data init;
+	int ret = 0;
+
+	pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL);
+	if (!pclk)
+		return ERR_PTR(-ENOMEM);
+
+	init.name =  kasprintf(GFP_KERNEL, "%s%d", PLT_CLK_NAME_BASE, id);
+	init.ops = &plt_clk_ops;
+	init.flags = 0;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+
+	pclk->hw.init = &init;
+	pclk->id = id;
+	pclk->offset = PMC_CLK_CTL_0 + id * PMC_CLK_CTL_SIZE;
+	spin_lock_init(&pclk->lock);
+
+	clk = clk_register(&pdev->dev, &pclk->hw);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto err_free_pclk;
+	}
+
+	pclk->lookup = clkdev_create(clk, init.name, NULL);
+	if (!pclk->lookup) {
+		ret = -ENOMEM;
+		goto err_clk_unregister;
+	}
+
+	kfree(init.name);
+
+	return clk;
+
+err_clk_unregister:
+	clk_unregister(clk);
+err_free_pclk:
+	kfree(init.name);
+	return ERR_PTR(ret);
+}
+
+static void plt_clk_unregister(struct clk *clk)
+{
+	struct clk_plt *pclk;
+	struct clk_hw *hw;
+
+	hw = __clk_get_hw(clk);
+	if (!hw)
+		return;
+
+	pclk = to_clk_plt(hw);
+
+	clkdev_drop(pclk->lookup);
+	clk_unregister(clk);
+}
+
+static struct clk_plt_fixed *plt_clk_register_fixed_rate(struct platform_device *pdev,
+						 const char *name,
+						 const char *parent_name,
+						 unsigned long fixed_rate)
+{
+	struct clk_plt_fixed *pclk;
+	int ret = 0;
+
+	pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL);
+	if (!pclk)
+		return ERR_PTR(-ENOMEM);
+
+	pclk->clk = clk_register_fixed_rate(&pdev->dev, name, parent_name,
+					    0, fixed_rate);
+	if (IS_ERR(pclk->clk)) {
+		ret = PTR_ERR(pclk->clk);
+		return ERR_PTR(ret);
+	}
+
+	pclk->lookup = clkdev_create(pclk->clk, name, NULL);
+	if (!pclk->lookup) {
+		ret = -ENOMEM;
+		goto err_clk_unregister;
+	}
+
+	return pclk;
+
+err_clk_unregister:
+	clk_unregister_fixed_rate(pclk->clk);
+	return ERR_PTR(ret);
+}
+
+static void plt_clk_unregister_fixed_rate(struct clk_plt_fixed *pclk)
+{
+	clkdev_drop(pclk->lookup);
+	clk_unregister_fixed_rate(pclk->clk);
+}
+
+static const char **plt_clk_register_parents(struct platform_device *pdev,
+					     struct clk_plt_data *data)
+{
+	struct pmc_clk **pclks, *clks;
+	const char **parent_names;
+	int i, err;
+
+	data->nparents = 0;
+	pclks = dev_get_platdata(&pdev->dev);
+	if (!pclks)
+		return NULL;
+
+	clks = *pclks;
+	while (clks[data->nparents].name)
+		data->nparents++;
+
+	data->parents = devm_kzalloc(&pdev->dev,
+				     sizeof(*data->parents) * data->nparents,
+				     GFP_KERNEL);
+	if (!data->parents) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	parent_names = kcalloc(data->nparents, sizeof(*parent_names),
+			       GFP_KERNEL);
+	if (!parent_names) {
+		err = -ENOMEM;
+		goto err_out;
+	}
+
+	for (i = 0; i < data->nparents; i++) {
+		data->parents[i] =
+			plt_clk_register_fixed_rate(pdev, clks[i].name,
+						    clks[i].parent_name,
+						    clks[i].freq);
+		if (IS_ERR(data->parents[i])) {
+			err = PTR_ERR(data->parents[i]);
+			goto err_unreg;
+		}
+		parent_names[i] = kstrdup_const(clks[i].name, GFP_KERNEL);
+	}
+
+	return parent_names;
+
+err_unreg:
+	for (i--; i >= 0; i--) {
+		plt_clk_unregister_fixed_rate(data->parents[i]);
+		kfree_const(parent_names[i]);
+	}
+	kfree(parent_names);
+err_out:
+	data->nparents = 0;
+	return ERR_PTR(err);
+}
+
+static void plt_clk_unregister_parents(struct clk_plt_data *data)
+{
+	int i;
+
+	for (i = 0; i < data->nparents; i++)
+		plt_clk_unregister_fixed_rate(data->parents[i]);
+}
+
+static int plt_clk_probe(struct platform_device *pdev)
+{
+	struct clk_plt_data *data;
+	int i, err;
+	const char **parent_names;
+
+	data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	parent_names = plt_clk_register_parents(pdev, data);
+	if (IS_ERR(parent_names))
+		return PTR_ERR(parent_names);
+
+	for (i = 0; i < PMC_CLK_NUM; i++) {
+		data->clks[i] = plt_clk_register(pdev, i, parent_names,
+						 data->nparents);
+		if (IS_ERR(data->clks[i])) {
+			err = PTR_ERR(data->clks[i]);
+			goto err_unreg_clk_plt;
+		}
+	}
+
+	for (i = 0; i < data->nparents; i++)
+		kfree_const(parent_names[i]);
+	kfree(parent_names);
+
+	dev_set_drvdata(&pdev->dev, data);
+	return 0;
+
+err_unreg_clk_plt:
+	for (i--; i >= 0; i--)
+		plt_clk_unregister(data->clks[i]);
+	plt_clk_unregister_parents(data);
+	for (i = 0; i < data->nparents; i++)
+		kfree_const(parent_names[i]);
+	kfree(parent_names);
+	return err;
+}
+
+static int plt_clk_remove(struct platform_device *pdev)
+{
+	struct clk_plt_data *data;
+	int i;
+
+	data = dev_get_drvdata(&pdev->dev);
+	if (!data)
+		return 0;
+
+	for (i = 0; i < PMC_CLK_NUM; i++)
+		plt_clk_unregister(data->clks[i]);
+	plt_clk_unregister_parents(data);
+	return 0;
+}
+
+static struct platform_driver plt_clk_driver = {
+	.driver = {
+		.name = PLT_CLK_DRIVER_NAME,
+	},
+	.probe = plt_clk_probe,
+	.remove = plt_clk_remove,
+};
+module_platform_driver(plt_clk_driver);
+
+MODULE_DESCRIPTION("Intel Atom platform clocks driver");
+MODULE_AUTHOR("Irina Tirdea <irina.tirdea@intel.com>");
+MODULE_LICENSE("GPL v2");