Message-Id: <1489744738-21632-4-git-send-email-cedric.madianga@gmail.com>
Date:   Fri, 17 Mar 2017 10:58:56 +0100
From:   M'boumba Cedric Madianga <cedric.madianga@...il.com>
To:     wsa@...-dreams.de, robh+dt@...nel.org, mcoquelin.stm32@...il.com,
        alexandre.torgue@...com, linus.walleij@...aro.org,
        pierre-yves.mordret@...com, linux@...linux.org.uk,
        linux-i2c@...r.kernel.org, devicetree@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Cc:     M'boumba Cedric Madianga <cedric.madianga@...il.com>
Subject: [PATCH 3/5] i2c: i2c-stm32f7: add driver

This patch adds initial support for the STM32F7 I2C controller.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@...il.com>
---
 drivers/i2c/busses/Kconfig       |  10 +
 drivers/i2c/busses/Makefile      |   1 +
 drivers/i2c/busses/i2c-stm32f7.c | 562 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 573 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-stm32f7.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 8adc0f1..ab0caec 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -897,6 +897,16 @@ config I2C_STM32F4
 	  This driver can also be built as module. If so, the module
 	  will be called i2c-stm32f4.
 
+config I2C_STM32F7
+	tristate "STMicroelectronics STM32F7 I2C support"
+	depends on ARCH_STM32 || COMPILE_TEST
+	help
+	  Enable this option to add support for STM32 I2C controller embedded
+	  in STM32F7 SoCs.
+
+	  This driver can also be built as module. If so, the module
+	  will be called i2c-stm32f7.
+
 config I2C_STU300
 	tristate "ST Microelectronics DDC I2C interface"
 	depends on MACH_U300
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 30b6085..5449ece 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -86,6 +86,7 @@ obj-$(CONFIG_I2C_SIMTEC)	+= i2c-simtec.o
 obj-$(CONFIG_I2C_SIRF)		+= i2c-sirf.o
 obj-$(CONFIG_I2C_ST)		+= i2c-st.o
 obj-$(CONFIG_I2C_STM32F4)	+= i2c-stm32f4.o
+obj-$(CONFIG_I2C_STM32F7)	+= i2c-stm32f7.o
 obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_SUN6I_P2WI)	+= i2c-sun6i-p2wi.o
 obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
new file mode 100644
index 0000000..844a98b
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -0,0 +1,562 @@
+/*
+ * Driver for STMicroelectronics STM32F7 I2C controller
+ *
+ * This I2C controller is described in the STM32F75xxx and STM32F74xxx Soc
+ * reference manual.
+ * Please see below a link to the documentation:
+ * http://www.st.com/resource/en/reference_manual/dm00124865.pdf
+ *
+ * Copyright (C) M'boumba Cedric Madianga 2017
+ * Author: M'boumba Cedric Madianga <cedric.madianga@...il.com>
+ *
+ * This driver is based on i2c-stm32f4.c
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+#include "i2c-stm32.h"
+
+/* STM32F7 I2C registers */
+#define STM32F7_I2C_CR1				0x00
+#define STM32F7_I2C_CR2				0x04
+#define STM32F7_I2C_TIMINGR			0x10
+#define STM32F7_I2C_ISR				0x18
+#define STM32F7_I2C_ICR				0x1C
+#define STM32F7_I2C_RXDR			0x24
+#define STM32F7_I2C_TXDR			0x28
+
+/* STM32F7 I2C control 1 */
+#define STM32F7_I2C_CR1_ERRIE			BIT(7)
+#define STM32F7_I2C_CR1_TCIE			BIT(6)
+#define STM32F7_I2C_CR1_STOPIE			BIT(5)
+#define STM32F7_I2C_CR1_NACKIE			BIT(4)
+#define STM32F7_I2C_CR1_ADDRIE			BIT(3)
+#define STM32F7_I2C_CR1_RXIE			BIT(2)
+#define STM32F7_I2C_CR1_TXIE			BIT(1)
+#define STM32F7_I2C_CR1_PE			BIT(0)
+#define STM32F7_I2C_ALL_IRQ_MASK		(STM32F7_I2C_CR1_ERRIE \
+						| STM32F7_I2C_CR1_TCIE \
+						| STM32F7_I2C_CR1_STOPIE \
+						| STM32F7_I2C_CR1_NACKIE \
+						| STM32F7_I2C_CR1_RXIE \
+						| STM32F7_I2C_CR1_TXIE)
+
+/* STM32F7 I2C control 2 */
+#define STM32F7_I2C_CR2_RELOAD			BIT(24)
+#define STM32F7_I2C_CR2_NBYTES_MASK		GENMASK(23, 16)
+#define STM32F7_I2C_CR2_NBYTES(n)		(((n) & 0xff) << 16)
+#define STM32F7_I2C_CR2_NACK			BIT(15)
+#define STM32F7_I2C_CR2_STOP			BIT(14)
+#define STM32F7_I2C_CR2_START			BIT(13)
+#define STM32F7_I2C_CR2_RD_WRN			BIT(10)
+#define STM32F7_I2C_CR2_SADD7_MASK		GENMASK(7, 1)
+#define STM32F7_I2C_CR2_SADD7(n)		(((n) & 0x7f) << 1)
+
+/* STM32F7 I2C Interrupt Status */
+#define STM32F7_I2C_ISR_BUSY			BIT(15)
+#define STM32F7_I2C_ISR_ARLO			BIT(9)
+#define STM32F7_I2C_ISR_BERR			BIT(8)
+#define STM32F7_I2C_ISR_TCR			BIT(7)
+#define STM32F7_I2C_ISR_TC			BIT(6)
+#define STM32F7_I2C_ISR_STOPF			BIT(5)
+#define STM32F7_I2C_ISR_NACKF			BIT(4)
+#define STM32F7_I2C_ISR_RXNE			BIT(2)
+#define STM32F7_I2C_ISR_TXIS			BIT(1)
+
+/* STM32F7 I2C Interrupt Clear */
+#define STM32F7_I2C_ICR_ARLOCF			BIT(9)
+#define STM32F7_I2C_ICR_BERRCF			BIT(8)
+#define STM32F7_I2C_ICR_STOPCF			BIT(5)
+#define STM32F7_I2C_ICR_NACKCF			BIT(4)
+
+#define STM32F7_I2C_MAX_LEN			0xff
+
+/**
+ * struct stm32f7_i2c_msg - client specific data
+ * @addr: 8-bit slave addr, including r/w bit
+ * @count: number of bytes to be transferred
+ * @buf: data buffer
+ * @result: result of the transfer
+ * @stop: last I2C msg to be sent, i.e. STOP to be generated
+ */
+struct stm32f7_i2c_msg {
+	u8 addr;
+	u32 count;
+	u8 *buf;
+	int result;
+	bool stop;
+};
+
+/**
+ * struct stm32f7_i2c_dev - private data of the controller
+ * @adap: I2C adapter for this controller
+ * @dev: device for this controller
+ * @base: virtual memory area
+ * @complete: completion of I2C message
+ * @clk: hw i2c clock
+ * @speed: I2C clock frequency of the controller. Standard, Fast or Fast+
+ * @msg: Pointer to data to be written
+ * @msg_num: number of I2C messages to be executed
+ * @msg_id: message identifiant
+ * @f7_msg: customized i2c msg for driver usage
+ */
+struct stm32f7_i2c_dev {
+	struct i2c_adapter adap;
+	struct device *dev;
+	void __iomem *base;
+	struct completion complete;
+	struct clk *clk;
+	int speed;
+	struct i2c_msg *msg;
+	unsigned int msg_num;
+	unsigned int msg_id;
+	struct stm32f7_i2c_msg f7_msg;
+};
+
+static inline void stm32f7_i2c_set_bits(void __iomem *reg, u32 mask)
+{
+	writel_relaxed(readl_relaxed(reg) | mask, reg);
+}
+
+static inline void stm32f7_i2c_clr_bits(void __iomem *reg, u32 mask)
+{
+	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
+}
+
+static int stm32f7_i2c_hw_config(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct device_node *of_node = i2c_dev->dev->of_node;
+	u32 timing;
+	int ret;
+
+	ret = of_property_read_u32(of_node, "st,i2c-timing", &timing);
+	if (ret) {
+		dev_err(i2c_dev->dev, "Error: missing i2c timing property\n");
+		return ret;
+	}
+
+	/* Timing settings */
+	writel_relaxed(timing, i2c_dev->base + STM32F7_I2C_TIMINGR);
+
+	/* Enable I2C */
+	writel_relaxed(STM32F7_I2C_CR1_PE, i2c_dev->base + STM32F7_I2C_CR1);
+
+	return 0;
+}
+
+static void stm32f7_i2c_write_tx_data(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+	void __iomem *base = i2c_dev->base;
+
+	if (f7_msg->count) {
+		writeb_relaxed(*f7_msg->buf++, base + STM32F7_I2C_TXDR);
+		f7_msg->count--;
+	}
+}
+
+static void stm32f7_i2c_read_rx_data(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+	void __iomem *base = i2c_dev->base;
+
+	if (f7_msg->count) {
+		*f7_msg->buf++ = readb_relaxed(base + STM32F7_I2C_RXDR);
+		f7_msg->count--;
+	}
+}
+
+static void stm32f7_i2c_reload(struct stm32f7_i2c_dev *i2c_dev)
+{
+	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+	u32 cr2;
+
+	cr2 = readl_relaxed(i2c_dev->base + STM32F7_I2C_CR2);
+
+	cr2 &= ~STM32F7_I2C_CR2_NBYTES_MASK;
+	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
+		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
+	} else {
+		cr2 &= ~STM32F7_I2C_CR2_RELOAD;
+		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
+	}
+
+	writel_relaxed(cr2, i2c_dev->base + STM32F7_I2C_CR2);
+}
+
+static int stm32f7_i2c_wait_free_bus(struct stm32f7_i2c_dev *i2c_dev)
+{
+	u32 status;
+	int ret;
+
+	ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F7_I2C_ISR,
+					 status,
+					 !(status & STM32F7_I2C_ISR_BUSY),
+					 10, 1000);
+	if (ret) {
+		dev_dbg(i2c_dev->dev, "bus busy\n");
+		ret = -EBUSY;
+	}
+
+	return ret;
+}
+
+static void stm32f7_i2c_xfer_msg(struct stm32f7_i2c_dev *i2c_dev,
+				 struct i2c_msg *msg)
+{
+	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+	void __iomem *base = i2c_dev->base;
+	u32 cr1, cr2;
+
+	f7_msg->addr = msg->addr;
+	f7_msg->buf = msg->buf;
+	f7_msg->count = msg->len;
+	f7_msg->result = 0;
+	f7_msg->stop = (i2c_dev->msg_id >= i2c_dev->msg_num - 1);
+
+	reinit_completion(&i2c_dev->complete);
+
+	cr1 = readl_relaxed(base + STM32F7_I2C_CR1);
+	cr2 = readl_relaxed(base + STM32F7_I2C_CR2);
+
+	/* Set transfer direction */
+	cr2 &= ~STM32F7_I2C_CR2_RD_WRN;
+	if (msg->flags & I2C_M_RD)
+		cr2 |= STM32F7_I2C_CR2_RD_WRN;
+
+	/* Set slave address */
+	cr2 &= ~STM32F7_I2C_CR2_SADD7_MASK;
+	cr2 |= STM32F7_I2C_CR2_SADD7(f7_msg->addr);
+
+	/* Set nb bytes to transfer and reload if needed */
+	cr2 &= ~(STM32F7_I2C_CR2_NBYTES_MASK | STM32F7_I2C_CR2_RELOAD);
+	if (f7_msg->count > STM32F7_I2C_MAX_LEN) {
+		cr2 |= STM32F7_I2C_CR2_NBYTES(STM32F7_I2C_MAX_LEN);
+		cr2 |= STM32F7_I2C_CR2_RELOAD;
+	} else {
+		cr2 |= STM32F7_I2C_CR2_NBYTES(f7_msg->count);
+	}
+
+	/* Enable NACK, STOP, error and transfer complete interrupts */
+	cr1 |= STM32F7_I2C_CR1_ERRIE | STM32F7_I2C_CR1_TCIE |
+		STM32F7_I2C_CR1_STOPIE | STM32F7_I2C_CR1_NACKIE;
+
+	/* Clear TX/RX interrupt */
+	cr1 &= ~(STM32F7_I2C_CR1_RXIE | STM32F7_I2C_CR1_TXIE);
+
+	/* Enable RX/TX interrupt according to msg direction */
+	if (msg->flags & I2C_M_RD)
+		cr1 |= STM32F7_I2C_CR1_RXIE;
+	else
+		cr1 |= STM32F7_I2C_CR1_TXIE;
+
+	/* Configure Start/Repeated Start */
+	cr2 |= STM32F7_I2C_CR2_START;
+
+	/* Write configurations registers */
+	writel_relaxed(cr1, base + STM32F7_I2C_CR1);
+	writel_relaxed(cr2, base + STM32F7_I2C_CR2);
+}
+
+static void stm32f7_i2c_disable_irq(struct stm32f7_i2c_dev *i2c_dev, u32 mask)
+{
+	stm32f7_i2c_clr_bits(i2c_dev->base + STM32F7_I2C_CR1, mask);
+}
+
+static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
+{
+	struct stm32f7_i2c_dev *i2c_dev = data;
+	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+	void __iomem *base = i2c_dev->base;
+	u32 status, mask;
+
+	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
+
+	/* Tx empty */
+	if (status & STM32F7_I2C_ISR_TXIS)
+		stm32f7_i2c_write_tx_data(i2c_dev);
+
+	/* RX not empty */
+	if (status & STM32F7_I2C_ISR_RXNE)
+		stm32f7_i2c_read_rx_data(i2c_dev);
+
+	/* NACK received */
+	if (status & STM32F7_I2C_ISR_NACKF) {
+		dev_dbg(i2c_dev->dev, "<%s>: Receive NACK\n", __func__);
+		writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
+		f7_msg->result = -EBADE;
+	}
+
+	/* STOP detection flag */
+	if (status & STM32F7_I2C_ISR_STOPF) {
+		/* Disable interrupts */
+		stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
+
+		/* Clear STOP flag */
+		writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
+
+		complete(&i2c_dev->complete);
+	}
+
+	/* Transfer complete */
+	if (status & STM32F7_I2C_ISR_TC) {
+		if (f7_msg->stop) {
+			mask = STM32F7_I2C_CR2_STOP;
+			stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
+		} else {
+			i2c_dev->msg_id++;
+			i2c_dev->msg++;
+			stm32f7_i2c_xfer_msg(i2c_dev, i2c_dev->msg);
+		}
+	}
+
+	/*
+	 * Transfer Complete Reload: 255 data bytes have been transferred
+	 * We have to prepare the I2C controller to transfer the remaining
+	 * data
+	 */
+	if (status & STM32F7_I2C_ISR_TCR)
+		stm32f7_i2c_reload(i2c_dev);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stm32f7_i2c_isr_error(int irq, void *data)
+{
+	struct stm32f7_i2c_dev *i2c_dev = data;
+	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+	void __iomem *base = i2c_dev->base;
+	struct device *dev = i2c_dev->dev;
+	u32 status;
+
+	status = readl_relaxed(i2c_dev->base + STM32F7_I2C_ISR);
+
+	/* Bus error */
+	if (status & STM32F7_I2C_ISR_BERR) {
+		dev_err(dev, "<%s>: Bus error\n", __func__);
+		writel_relaxed(STM32F7_I2C_ICR_BERRCF, base + STM32F7_I2C_ICR);
+		f7_msg->result = -EIO;
+	}
+
+	/* Arbitration loss */
+	if (status & STM32F7_I2C_ISR_ARLO) {
+		dev_err(dev, "<%s>: Arbitration loss\n", __func__);
+		writel_relaxed(STM32F7_I2C_ICR_ARLOCF, base + STM32F7_I2C_ICR);
+		f7_msg->result = -EAGAIN;
+	}
+
+	stm32f7_i2c_disable_irq(i2c_dev, STM32F7_I2C_ALL_IRQ_MASK);
+
+	complete(&i2c_dev->complete);
+
+	return IRQ_HANDLED;
+}
+
+static int stm32f7_i2c_xfer(struct i2c_adapter *i2c_adap,
+			    struct i2c_msg msgs[], int num)
+{
+	struct stm32f7_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
+	struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+	unsigned long timeout;
+	int ret;
+
+	i2c_dev->msg = msgs;
+	i2c_dev->msg_num = num;
+	i2c_dev->msg_id = 0;
+
+	ret = clk_enable(i2c_dev->clk);
+	if (ret) {
+		dev_err(i2c_dev->dev, "Failed to enable clock\n");
+		return ret;
+	}
+
+	ret = stm32f7_i2c_wait_free_bus(i2c_dev);
+	if (ret)
+		goto clk_free;
+
+	stm32f7_i2c_xfer_msg(i2c_dev, msgs);
+
+	timeout = wait_for_completion_timeout(&i2c_dev->complete,
+					      i2c_dev->adap.timeout);
+	ret = f7_msg->result;
+
+	if (!timeout) {
+		dev_dbg(i2c_dev->dev, "Access to slave 0x%x timed out\n",
+			i2c_dev->msg->addr);
+		ret = -ETIMEDOUT;
+	}
+
+clk_free:
+	clk_disable(i2c_dev->clk);
+
+	return (ret < 0) ? ret : num;
+}
+
+static u32 stm32f7_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm stm32f7_i2c_algo = {
+	.master_xfer = stm32f7_i2c_xfer,
+	.functionality = stm32f7_i2c_func,
+};
+
+static int stm32f7_i2c_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct stm32f7_i2c_dev *i2c_dev;
+	struct resource *res;
+	u32 irq_event, irq_error, clk_rate;
+	struct i2c_adapter *adap;
+	struct reset_control *rst;
+	int ret;
+
+	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
+	if (!i2c_dev)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	i2c_dev->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(i2c_dev->base))
+		return PTR_ERR(i2c_dev->base);
+
+	irq_event = irq_of_parse_and_map(np, 0);
+	if (!irq_event) {
+		dev_err(&pdev->dev, "IRQ event missing or invalid\n");
+		return -EINVAL;
+	}
+
+	irq_error = irq_of_parse_and_map(np, 1);
+	if (!irq_error) {
+		dev_err(&pdev->dev, "IRQ error missing or invalid\n");
+		return -EINVAL;
+	}
+
+	i2c_dev->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(i2c_dev->clk)) {
+		dev_err(&pdev->dev, "Error: Missing controller clock\n");
+		return PTR_ERR(i2c_dev->clk);
+	}
+	ret = clk_prepare_enable(i2c_dev->clk);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to prepare_enable clock\n");
+		return ret;
+	}
+
+	rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(rst)) {
+		dev_err(&pdev->dev, "Error: Missing controller reset\n");
+		ret = PTR_ERR(rst);
+		goto clk_free;
+	}
+	reset_control_assert(rst);
+	udelay(2);
+	reset_control_deassert(rst);
+
+	i2c_dev->speed = STM32_I2C_SPEED_STANDARD;
+	ret = of_property_read_u32(np, "clock-frequency", &clk_rate);
+	if ((!ret) && (clk_rate == 400000))
+		i2c_dev->speed = STM32_I2C_SPEED_FAST;
+	else if ((!ret) && (clk_rate == 1000000))
+		i2c_dev->speed = STM32_I2C_SPEED_FAST_PLUS;
+
+	i2c_dev->dev = &pdev->dev;
+
+	ret = devm_request_irq(&pdev->dev, irq_event, stm32f7_i2c_isr_event, 0,
+			       pdev->name, i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq event %i\n",
+			irq_event);
+		goto clk_free;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq_error, stm32f7_i2c_isr_error, 0,
+			       pdev->name, i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq error %i\n",
+			irq_error);
+		goto clk_free;
+	}
+
+	ret = stm32f7_i2c_hw_config(i2c_dev);
+	if (ret)
+		goto clk_free;
+
+	adap = &i2c_dev->adap;
+	i2c_set_adapdata(adap, i2c_dev);
+	snprintf(adap->name, sizeof(adap->name), "STM32F7 I2C(%pa)",
+		 &res->start);
+	adap->owner = THIS_MODULE;
+	adap->timeout = 2 * HZ;
+	adap->retries = 0;
+	adap->algo = &stm32f7_i2c_algo;
+	adap->dev.parent = &pdev->dev;
+	adap->dev.of_node = pdev->dev.of_node;
+
+	init_completion(&i2c_dev->complete);
+
+	ret = i2c_add_adapter(adap);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add adapter\n");
+		goto clk_free;
+	}
+
+	platform_set_drvdata(pdev, i2c_dev);
+
+	clk_disable(i2c_dev->clk);
+
+	dev_info(i2c_dev->dev, "STM32F7 I2C-%d driver registered\n", adap->nr);
+
+	return 0;
+
+clk_free:
+	clk_disable_unprepare(i2c_dev->clk);
+
+	return ret;
+}
+
+static int stm32f7_i2c_remove(struct platform_device *pdev)
+{
+	struct stm32f7_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&i2c_dev->adap);
+
+	clk_unprepare(i2c_dev->clk);
+
+	return 0;
+}
+
+static const struct of_device_id stm32f7_i2c_match[] = {
+	{ .compatible = "st,stm32f7-i2c", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32f7_i2c_match);
+
+static struct platform_driver stm32f7_i2c_driver = {
+	.driver = {
+		.name = "stm32f7-i2c",
+		.of_match_table = stm32f7_i2c_match,
+	},
+	.probe = stm32f7_i2c_probe,
+	.remove = stm32f7_i2c_remove,
+};
+
+module_platform_driver(stm32f7_i2c_driver);
+
+MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@...il.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32F7 I2C driver");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

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