[v5,2/3] i2c: iproc: Add Broadcom iProc I2C Driver

Message ID	1421451737-7107-3-git-send-email-rjui@broadcom.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Ray Jui <rjui@broadcom.com> To: Wolfram Sang <wsa@the-dreams.de>, =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>, Rob Herring <robh+dt@kernel.org>, "Pawel Moll" <pawel.moll@arm.com>, Mark Rutland <mark.rutland@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, Kumar Gala <galak@codeaurora.org>, "Grant Likely" <grant.likely@linaro.org>, Christian Daudt <bcm@fixthebug.org>, Matt Porter <mporter@linaro.org>, Florian Fainelli <f.fainelli@gmail.com>, Russell King <linux@arm.linux.org.uk> Subject: [PATCH v5 2/3] i2c: iproc: Add Broadcom iProc I2C Driver Date: Fri, 16 Jan 2015 15:42:16 -0800 Message-ID: <1421451737-7107-3-git-send-email-rjui@broadcom.com> In-Reply-To: <1421451737-7107-1-git-send-email-rjui@broadcom.com> References: <Ray Jui <rjui@broadcom.com> <1421451737-7107-1-git-send-email-rjui@broadcom.com> MIME-Version: 1.0 Cc: devicetree@vger.kernel.org, Scott Branden <sbranden@broadcom.com>, Ray Jui <rjui@broadcom.com>, linux-kernel@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 31e8308..af76d23 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -372,6 +372,16 @@ config I2C_BCM2835 This support is also available as a module. If so, the module will be called i2c-bcm2835. +config I2C_BCM_IPROC + tristate "Broadcom iProc I2C controller" + depends on ARCH_BCM_IPROC || COMPILE_TEST + default ARCH_BCM_IPROC + help + If you say yes to this option, support will be included for the + Broadcom iProc I2C controller. + + If you don't know what to do here, say N. + config I2C_BCM_KONA tristate "BCM Kona I2C adapter" depends on ARCH_BCM_MOBILE diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 56388f6..d93b509 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_I2C_AT91) += i2c-at91.o obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o obj-$(CONFIG_I2C_AXXIA) += i2c-axxia.o obj-$(CONFIG_I2C_BCM2835) += i2c-bcm2835.o +obj-$(CONFIG_I2C_BCM_IPROC) += i2c-bcm-iproc.o obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o obj-$(CONFIG_I2C_CADENCE) += i2c-cadence.o obj-$(CONFIG_I2C_CBUS_GPIO) += i2c-cbus-gpio.o diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c new file mode 100644 index 0000000..a92d8f5 --- /dev/null +++ b/drivers/i2c/busses/i2c-bcm-iproc.c @@ -0,0 +1,493 @@ +/* + * Copyright (C) 2014 Broadcom Corporation + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/delay.h> + +#define CFG_OFFSET 0x00 +#define CFG_RESET_SHIFT 31 +#define CFG_EN_SHIFT 30 +#define CFG_M_RETRY_CNT_SHIFT 16 +#define CFG_M_RETRY_CNT_MASK 0x0f + +#define TIM_CFG_OFFSET 0x04 +#define TIM_CFG_MODE_400_SHIFT 31 + +#define M_FIFO_CTRL_OFFSET 0x0c +#define M_FIFO_RX_FLUSH_SHIFT 31 +#define M_FIFO_TX_FLUSH_SHIFT 30 +#define M_FIFO_RX_CNT_SHIFT 16 +#define M_FIFO_RX_CNT_MASK 0x7f +#define M_FIFO_RX_THLD_SHIFT 8 +#define M_FIFO_RX_THLD_MASK 0x3f + +#define M_CMD_OFFSET 0x30 +#define M_CMD_START_BUSY_SHIFT 31 +#define M_CMD_STATUS_SHIFT 25 +#define M_CMD_STATUS_MASK 0x07 +#define M_CMD_STATUS_SUCCESS 0x0 +#define M_CMD_STATUS_LOST_ARB 0x1 +#define M_CMD_STATUS_NACK_ADDR 0x2 +#define M_CMD_STATUS_NACK_DATA 0x3 +#define M_CMD_STATUS_TIMEOUT 0x4 +#define M_CMD_PROTOCOL_SHIFT 9 +#define M_CMD_PROTOCOL_MASK 0xf +#define M_CMD_PROTOCOL_BLK_WR 0x7 +#define M_CMD_PROTOCOL_BLK_RD 0x8 +#define M_CMD_PEC_SHIFT 8 +#define M_CMD_RD_CNT_SHIFT 0 +#define M_CMD_RD_CNT_MASK 0xff + +#define IE_OFFSET 0x38 +#define IE_M_RX_FIFO_FULL_SHIFT 31 +#define IE_M_RX_THLD_SHIFT 30 +#define IE_M_START_BUSY_SHIFT 28 + +#define IS_OFFSET 0x3c +#define IS_M_RX_FIFO_FULL_SHIFT 31 +#define IS_M_RX_THLD_SHIFT 30 +#define IS_M_START_BUSY_SHIFT 28 + +#define M_TX_OFFSET 0x40 +#define M_TX_WR_STATUS_SHIFT 31 +#define M_TX_DATA_SHIFT 0 +#define M_TX_DATA_MASK 0xff + +#define M_RX_OFFSET 0x44 +#define M_RX_STATUS_SHIFT 30 +#define M_RX_STATUS_MASK 0x03 +#define M_RX_PEC_ERR_SHIFT 29 +#define M_RX_DATA_SHIFT 0 +#define M_RX_DATA_MASK 0xff + +#define I2C_TIMEOUT_MESC 100 +#define M_TX_RX_FIFO_SIZE 64 + +enum bus_speed_index { + I2C_SPD_100K = 0, + I2C_SPD_400K, +}; + +struct bcm_iproc_i2c_dev { + struct device *device; + int irq; + + void __iomem *base; + + struct i2c_adapter adapter; + + struct completion done; +}; + +/* + * Can be expanded in the future if more interrupt status bits are utilized + */ +#define ISR_MASK (1 << IS_M_START_BUSY_SHIFT) + +static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = data; + u32 status = readl(iproc_i2c->base + IS_OFFSET); + + status &= ISR_MASK; + + if (!status) + return IRQ_NONE; + + writel(status, iproc_i2c->base + IS_OFFSET); + complete_all(&iproc_i2c->done); + + return IRQ_HANDLED; +} + +static bool bcm_iproc_i2c_bus_busy(struct bcm_iproc_i2c_dev *iproc_i2c) +{ + if (readl(iproc_i2c->base + M_CMD_OFFSET) & + (1 << M_CMD_START_BUSY_SHIFT)) + return true; + else + return false; +} + +static int bcm_iproc_i2c_format_addr(struct bcm_iproc_i2c_dev *iproc_i2c, + struct i2c_msg *msg, u8 *addr) +{ + + if (msg->flags & I2C_M_TEN) { + dev_err(iproc_i2c->device, "no support for 10-bit address\n"); + return -EINVAL; + } + + *addr = msg->addr << 1; + + if (msg->flags & I2C_M_RD) + *addr |= 1; + + return 0; +} + +static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c, + struct i2c_msg *msg) +{ + u32 val; + + val = readl(iproc_i2c->base + M_CMD_OFFSET); + val = (val >> M_CMD_STATUS_SHIFT) & M_CMD_STATUS_MASK; + + switch (val) { + case M_CMD_STATUS_SUCCESS: + return 0; + + case M_CMD_STATUS_LOST_ARB: + dev_dbg(iproc_i2c->device, "lost bus arbitration\n"); + return -EAGAIN; + + case M_CMD_STATUS_NACK_ADDR: + dev_dbg(iproc_i2c->device, "NAK addr:0x%02x\n", msg->addr); + return -ENXIO; + + case M_CMD_STATUS_NACK_DATA: + dev_dbg(iproc_i2c->device, "NAK data\n"); + return -ENXIO; + + case M_CMD_STATUS_TIMEOUT: + dev_dbg(iproc_i2c->device, "bus timeout\n"); + return -ETIMEDOUT; + + default: + dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val); + return -EIO; + } +} + +static int bcm_iproc_i2c_xfer_single_msg(struct bcm_iproc_i2c_dev *iproc_i2c, + struct i2c_msg *msg) +{ + int ret, i; + u8 addr; + u32 val; + unsigned long time_left = msecs_to_jiffies(I2C_TIMEOUT_MESC); + + if (msg->len > M_TX_RX_FIFO_SIZE - 1) { + dev_err(iproc_i2c->device, + "only support data length up to %u bytes\n", + M_TX_RX_FIFO_SIZE - 1); + return -EINVAL; + } + + if (bcm_iproc_i2c_bus_busy(iproc_i2c)) { + dev_warn(iproc_i2c->device, "bus is busy\n"); + return -EBUSY; + } + + ret = bcm_iproc_i2c_format_addr(iproc_i2c, msg, &addr); + if (ret) + return ret; + + /* load slave address into the TX FIFO */ + writel(addr, iproc_i2c->base + M_TX_OFFSET); + + /* for a write transaction, load data into the TX FIFO */ + if (!(msg->flags & I2C_M_RD)) { + for (i = 0; i < msg->len; i++) { + val = msg->buf[i]; + + /* mark the last byte */ + if (i == msg->len - 1) + val |= 1 << M_TX_WR_STATUS_SHIFT; + + writel(val, iproc_i2c->base + M_TX_OFFSET); + } + + if (msg->len == 0) + writel(1 << M_TX_WR_STATUS_SHIFT, + iproc_i2c->base + M_TX_OFFSET); + } + + /* mark as incomplete before starting the transaction */ + reinit_completion(&iproc_i2c->done); + + /* + * Enable the "start busy" interrupt, which will be triggered after the + * transaction is done, i.e., the internal start_busy bit, transitions + * from 1 to 0. + */ + writel(1 << IE_M_START_BUSY_SHIFT, iproc_i2c->base + IE_OFFSET); + + /* + * Now we can activate the transfer. For a read operation, specify the + * number of bytes to read + */ + val = 1 << M_CMD_START_BUSY_SHIFT; + if (msg->flags & I2C_M_RD) { + val |= (M_CMD_PROTOCOL_BLK_RD << M_CMD_PROTOCOL_SHIFT) | + (msg->len << M_CMD_RD_CNT_SHIFT); + } else { + val |= (M_CMD_PROTOCOL_BLK_WR << M_CMD_PROTOCOL_SHIFT); + } + writel(val, iproc_i2c->base + M_CMD_OFFSET); + + time_left = wait_for_completion_timeout(&iproc_i2c->done, time_left); + + /* disable all interrupts */ + writel(0, iproc_i2c->base + IE_OFFSET); + + if (!time_left) { + dev_err(iproc_i2c->device, "transaction timed out\n"); + + /* flush FIFOs */ + val = (1 << M_FIFO_RX_FLUSH_SHIFT) | + (1 << M_FIFO_TX_FLUSH_SHIFT); + writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET); + return -ETIMEDOUT; + } + + ret = bcm_iproc_i2c_check_status(iproc_i2c, msg); + if (ret) { + /* flush both TX/RX FIFOs */ + val = (1 << M_FIFO_RX_FLUSH_SHIFT) | + (1 << M_FIFO_TX_FLUSH_SHIFT); + writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET); + return ret; + } + + /* + * For a read operation, we now need to load the data from FIFO + * into the memory buffer + */ + if (msg->flags & I2C_M_RD) { + for (i = 0; i < msg->len; i++) { + msg->buf[i] = (readl(iproc_i2c->base + M_RX_OFFSET) >> + M_RX_DATA_SHIFT) & M_RX_DATA_MASK; + } + } + + dev_dbg(iproc_i2c->device, "xfer %c, addr=0x%02x, len=%d\n", + (msg->flags & I2C_M_RD) ? 'R' : 'W', msg->addr, + msg->len); + dev_dbg(iproc_i2c->device, "**** data start ****\n"); + for (i = 0; i < msg->len; i++) + dev_dbg(iproc_i2c->device, "0x%02x ", msg->buf[i]); + dev_dbg(iproc_i2c->device, "**** data end ****\n"); + + return 0; +} + +static int bcm_iproc_i2c_xfer(struct i2c_adapter *adapter, + struct i2c_msg msgs[], int num) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = i2c_get_adapdata(adapter); + int ret, i; + + /* go through all messages */ + for (i = 0; i < num; i++) { + ret = bcm_iproc_i2c_xfer_single_msg(iproc_i2c, &msgs[i]); + if (ret) { + dev_err(iproc_i2c->device, "xfer failed\n"); + return ret; + } + } + + return num; +} + +static uint32_t bcm_iproc_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm bcm_iproc_algo = { + .master_xfer = bcm_iproc_i2c_xfer, + .functionality = bcm_iproc_i2c_functionality, +}; + +static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c) +{ + unsigned int bus_speed, speed_bit; + u32 val; + int ret = of_property_read_u32(iproc_i2c->device->of_node, + "clock-frequency", &bus_speed); + if (ret < 0) { + dev_info(iproc_i2c->device, + "unable to interpret clock-frequency DT property\n"); + bus_speed = 100000; + } + + if (bus_speed < 100000) { + dev_err(iproc_i2c->device, "%d Hz bus speed not supported\n", + bus_speed); + dev_err(iproc_i2c->device, + "valid speeds are 100khz and 400khz\n"); + return -EINVAL; + } else if (bus_speed < 400000) { + speed_bit = 0; + } else { + /* bus_speed >= 400000 */ + speed_bit = 1; + } + + val = readl(iproc_i2c->base + TIM_CFG_OFFSET); + val &= ~(1 << TIM_CFG_MODE_400_SHIFT); + val |= speed_bit << TIM_CFG_MODE_400_SHIFT; + writel(val, iproc_i2c->base + TIM_CFG_OFFSET); + + dev_info(iproc_i2c->device, "bus set to %u Hz\n", bus_speed); + + return 0; +} + +static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c) +{ + u32 val; + + /* put controller in reset */ + val = readl(iproc_i2c->base + CFG_OFFSET); + val |= 1 << CFG_RESET_SHIFT; + val &= ~(1 << CFG_EN_SHIFT); + writel(val, iproc_i2c->base + CFG_OFFSET); + + /* wait 100 usec per spec */ + udelay(100); + + /* bring controller out of reset */ + val &= ~(1 << CFG_RESET_SHIFT); + writel(val, iproc_i2c->base + CFG_OFFSET); + + /* flush TX/RX FIFOs and set RX FIFO threshold to zero */ + val = (1 << M_FIFO_RX_FLUSH_SHIFT) | (1 << M_FIFO_TX_FLUSH_SHIFT); + writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET); + + /* disable all interrupts */ + writel(0, iproc_i2c->base + IE_OFFSET); + + /* clear all pending interrupts */ + writel(0xffffffff, iproc_i2c->base + IS_OFFSET); + + return 0; +} + +static void bcm_iproc_i2c_enable(struct bcm_iproc_i2c_dev *iproc_i2c) +{ + u32 val; + + val = readl(iproc_i2c->base + CFG_OFFSET); + val |= 1 << CFG_EN_SHIFT; + writel(val, iproc_i2c->base + CFG_OFFSET); +} + +static void bcm_iproc_i2c_disable(struct bcm_iproc_i2c_dev *iproc_i2c) +{ + u32 val; + + val = readl(iproc_i2c->base + CFG_OFFSET); + val &= ~(1 << CFG_EN_SHIFT); + writel(val, iproc_i2c->base + CFG_OFFSET); +} + +static int bcm_iproc_i2c_probe(struct platform_device *pdev) +{ + int irq, ret = 0; + struct bcm_iproc_i2c_dev *iproc_i2c; + struct i2c_adapter *adap; + struct resource *res; + + iproc_i2c = devm_kzalloc(&pdev->dev, sizeof(*iproc_i2c), + GFP_KERNEL); + if (!iproc_i2c) + return -ENOMEM; + + platform_set_drvdata(pdev, iproc_i2c); + iproc_i2c->device = &pdev->dev; + init_completion(&iproc_i2c->done); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + iproc_i2c->base = devm_ioremap_resource(iproc_i2c->device, res); + if (IS_ERR(iproc_i2c->base)) + return PTR_ERR(iproc_i2c->base); + + ret = bcm_iproc_i2c_init(iproc_i2c); + if (ret) + return ret; + + ret = bcm_iproc_i2c_cfg_speed(iproc_i2c); + if (ret) + return ret; + + irq = platform_get_irq(pdev, 0); + if (irq <= 0) { + dev_err(iproc_i2c->device, "no irq resource\n"); + return irq; + } + iproc_i2c->irq = irq; + + ret = devm_request_irq(iproc_i2c->device, irq, bcm_iproc_i2c_isr, 0, + pdev->name, iproc_i2c); + if (ret < 0) { + dev_err(iproc_i2c->device, "unable to request irq %i\n", irq); + return ret; + } + + bcm_iproc_i2c_enable(iproc_i2c); + + adap = &iproc_i2c->adapter; + i2c_set_adapdata(adap, iproc_i2c); + strlcpy(adap->name, "Broadcom iProc I2C adapter", sizeof(adap->name)); + adap->algo = &bcm_iproc_algo; + adap->dev.parent = &pdev->dev; + adap->dev.of_node = pdev->dev.of_node; + + ret = i2c_add_adapter(adap); + if (ret) { + dev_err(iproc_i2c->device, "failed to add adapter\n"); + return ret; + } + + return 0; +} + +static int bcm_iproc_i2c_remove(struct platform_device *pdev) +{ + struct bcm_iproc_i2c_dev *iproc_i2c = platform_get_drvdata(pdev); + + disable_irq(iproc_i2c->irq); + i2c_del_adapter(&iproc_i2c->adapter); + bcm_iproc_i2c_disable(iproc_i2c); + + return 0; +} + +static const struct of_device_id bcm_iproc_i2c_of_match[] = { + { .compatible = "brcm,iproc-i2c" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, bcm_iproc_i2c_of_match); + +static struct platform_driver bcm_iproc_i2c_driver = { + .driver = { + .name = "bcm-iproc-i2c", + .of_match_table = bcm_iproc_i2c_of_match, + }, + .probe = bcm_iproc_i2c_probe, + .remove = bcm_iproc_i2c_remove, +}; +module_platform_driver(bcm_iproc_i2c_driver); + +MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>"); +MODULE_DESCRIPTION("Broadcom iProc I2C Driver"); +MODULE_LICENSE("GPL v2");

[v5,2/3] i2c: iproc: Add Broadcom iProc I2C Driver

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