[PATCH v5 0/5] Add support for the STM32F4 I2C

[PATCH v5 0/5] Add support for the STM32F4 I2C

[M'boumba Cedric Madianga]

This patchset adds support for the I2C controller embedded in STM32F4xx SoC.
It enables I2C transfer in interrupt mode with Standard-mode and Fast-mode bus
speed.

Changes since v4:
- Use clamp() function to use a value in a given range as it was missed in V4

M'boumba Cedric Madianga (5):
  dt-bindings: Document the STM32 I2C bindings
  i2c: Add STM32F4 I2C driver
  ARM: dts: Add I2C1 support for STM32F429 SoC
  ARM: dts: Add I2C1 support for STM32429 eval board
  ARM: configs: Add I2C support for STM32 defconfig

 .../devicetree/bindings/i2c/i2c-stm32.txt          |  33 +
 arch/arm/boot/dts/stm32429i-eval.dts               |   6 +
 arch/arm/boot/dts/stm32f429.dtsi                   |  23 +
 arch/arm/configs/stm32_defconfig                   |   3 +
 drivers/i2c/busses/Kconfig                         |  10 +
 drivers/i2c/busses/Makefile                        |   1 +
 drivers/i2c/busses/i2c-stm32f4.c                   | 851 +++++++++++++++++++++
 7 files changed, 927 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-stm32.txt
 create mode 100644 drivers/i2c/busses/i2c-stm32f4.c

-- 
1.9.1

[PATCH v5 1/5] dt-bindings: Document the STM32 I2C bindings

[M'boumba Cedric Madianga]

This patch adds documentation of device tree bindings for the STM32 I2C
controller.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/i2c/i2c-stm32.txt          | 33 ++++++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-stm32.txt

diff --git a/Documentation/devicetree/bindings/i2c/i2c-stm32.txt b/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
new file mode 100644
index 0000000..78eaf7b
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
@@ -0,0 +1,33 @@
+* I2C controller embedded in STMicroelectronics STM32 I2C platform
+
+Required properties :
+- compatible : Must be "st,stm32f4-i2c"
+- reg : Offset and length of the register set for the device
+- interrupts : Must contain the interrupt id for I2C event and then the
+  interrupt id for I2C error.
+- resets: Must contain the phandle to the reset controller.
+- clocks: Must contain the input clock of the I2C instance.
+- A pinctrl state named "default" must be defined to set pins in mode of
+  operation for I2C transfer
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Optional properties :
+- clock-frequency : Desired I2C bus clock frequency in Hz. If not specified,
+  the default 100 kHz frequency will be used. As only Normal and Fast modes
+  are supported, possible values are 100000 and 400000.
+
+Example :
+
+	i2c at 40005400 {
+		compatible = "st,stm32f4-i2c";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0x40005400 0x400>;
+		interrupts = <31>,
+			     <32>;
+		resets = <&rcc 277>;
+		clocks = <&rcc 0 149>;
+		pinctrl-0 = <&i2c1_sda_pin>, <&i2c1_scl_pin>;
+		pinctrl-names = "default";
+	};
-- 
1.9.1

[PATCH v5 2/5] i2c: Add STM32F4 I2C driver

[M'boumba Cedric Madianga]

This patch adds support for the STM32F4 I2C controller.

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 drivers/i2c/busses/Kconfig       |  10 +
 drivers/i2c/busses/Makefile      |   1 +
 drivers/i2c/busses/i2c-stm32f4.c | 851 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 862 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-stm32f4.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 8e43914..584e0d7 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -886,6 +886,16 @@ config I2C_ST
 	  This driver can also be built as module. If so, the module
 	  will be called i2c-st.
 
+config I2C_STM32F4
+	tristate "STMicroelectronics STM32F4 I2C support"
+	depends on ARCH_STM32  || COMPILE_TEST
+	help
+	  Enable this option to add support for STM32 I2C controller embedded
+	  in STM32F4 SoCs.
+
+	  This driver can also be built as module. If so, the module
+	  will be called i2c-stm32f4.
+
 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 1c1bac8..a2c6ff5 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -85,6 +85,7 @@ obj-$(CONFIG_I2C_SH_MOBILE)	+= i2c-sh_mobile.o
 obj-$(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_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-stm32f4.c b/drivers/i2c/busses/i2c-stm32f4.c
new file mode 100644
index 0000000..0630354
--- /dev/null
+++ b/drivers/i2c/busses/i2c-stm32f4.c
@@ -0,0 +1,851 @@
+/*
+ * Driver for STMicroelectronics STM32 I2C controller
+ *
+ * Copyright (C) M'boumba Cedric Madianga 2015
+ * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
+ *
+ * This driver is based on i2c-st.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_address.h>
+#include <linux/of_irq.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+/* STM32F4 I2C offset registers */
+#define STM32F4_I2C_CR1			0x00
+#define STM32F4_I2C_CR2			0x04
+#define STM32F4_I2C_DR			0x10
+#define STM32F4_I2C_SR1			0x14
+#define STM32F4_I2C_SR2			0x18
+#define STM32F4_I2C_CCR			0x1C
+#define STM32F4_I2C_TRISE		0x20
+#define STM32F4_I2C_FLTR		0x24
+
+/* STM32F4 I2C control 1*/
+#define STM32F4_I2C_CR1_SWRST		BIT(15)
+#define STM32F4_I2C_CR1_POS		BIT(11)
+#define STM32F4_I2C_CR1_ACK		BIT(10)
+#define STM32F4_I2C_CR1_STOP		BIT(9)
+#define STM32F4_I2C_CR1_START		BIT(8)
+#define STM32F4_I2C_CR1_PE		BIT(0)
+
+/* STM32F4 I2C control 2 */
+#define STM32F4_I2C_CR2_FREQ_MASK	GENMASK(5, 0)
+#define STM32F4_I2C_CR2_FREQ(n)		((n & STM32F4_I2C_CR2_FREQ_MASK))
+#define STM32F4_I2C_CR2_ITBUFEN		BIT(10)
+#define STM32F4_I2C_CR2_ITEVTEN		BIT(9)
+#define STM32F4_I2C_CR2_ITERREN		BIT(8)
+#define STM32F4_I2C_CR2_IRQ_MASK	(STM32F4_I2C_CR2_ITBUFEN \
+					| STM32F4_I2C_CR2_ITEVTEN \
+					| STM32F4_I2C_CR2_ITERREN)
+
+/* STM32F4 I2C Status 1 */
+#define STM32F4_I2C_SR1_AF		BIT(10)
+#define STM32F4_I2C_SR1_ARLO		BIT(9)
+#define STM32F4_I2C_SR1_BERR		BIT(8)
+#define STM32F4_I2C_SR1_TXE		BIT(7)
+#define STM32F4_I2C_SR1_RXNE		BIT(6)
+#define STM32F4_I2C_SR1_BTF		BIT(2)
+#define STM32F4_I2C_SR1_ADDR		BIT(1)
+#define STM32F4_I2C_SR1_SB		BIT(0)
+#define STM32F4_I2C_SR1_ITEVTEN_MASK	(STM32F4_I2C_SR1_BTF \
+					| STM32F4_I2C_SR1_ADDR \
+					| STM32F4_I2C_SR1_SB)
+#define STM32F4_I2C_SR1_ITBUFEN_MASK	(STM32F4_I2C_SR1_TXE \
+					| STM32F4_I2C_SR1_RXNE)
+#define STM32F4_I2C_SR1_ITERREN_MASK	(STM32F4_I2C_SR1_AF \
+					| STM32F4_I2C_SR1_ARLO \
+					| STM32F4_I2C_SR1_BERR)
+
+/* STM32F4 I2C Status 2 */
+#define STM32F4_I2C_SR2_BUSY		BIT(1)
+
+/* STM32F4 I2C Control Clock */
+#define STM32F4_I2C_CCR_CCR_MASK	GENMASK(11, 0)
+#define STM32F4_I2C_CCR_CCR(n)		((n & STM32F4_I2C_CCR_CCR_MASK))
+#define STM32F4_I2C_CCR_FS		BIT(15)
+#define STM32F4_I2C_CCR_DUTY		BIT(14)
+
+/* STM32F4 I2C Trise */
+#define STM32F4_I2C_TRISE_VALUE_MASK	GENMASK(5, 0)
+#define STM32F4_I2C_TRISE_VALUE(n)	((n & STM32F4_I2C_TRISE_VALUE_MASK))
+
+/* STM32F4 I2C Filter */
+#define STM32F4_I2C_FLTR_DNF_MASK	GENMASK(3, 0)
+#define STM32F4_I2C_FLTR_DNF(n)		((n & STM32F4_I2C_FLTR_DNF_MASK))
+#define STM32F4_I2C_FLTR_ANOFF		BIT(4)
+
+#define STM32F4_I2C_MIN_FREQ		2
+#define STM32F4_I2C_MAX_FREQ		42
+#define FAST_MODE_MAX_RISE_TIME		1000
+#define STD_MODE_MAX_RISE_TIME		300
+#define MHZ_TO_HZ			1000000
+
+enum stm32f4_i2c_speed {
+	STM32F4_I2C_SPEED_STANDARD, /* 100 kHz */
+	STM32F4_I2C_SPEED_FAST, /* 400 kHz */
+	STM32F4_I2C_SPEED_END,
+};
+
+/**
+ * struct stm32f4_i2c_timings - per-Mode tuning parameters
+ * @duty: Fast mode duty cycle
+ * @mul_ccr: Value to be multiplied to CCR to reach 100Khz/400Khz SCL frequency
+ * @min_ccr: Minimum clock ctrl reg value to reach 100Khz/400Khz SCL frequency
+ */
+struct stm32f4_i2c_timings {
+	u32 rate;
+	u32 duty;
+	u32 mul_ccr;
+	u32 min_ccr;
+};
+
+/**
+ * struct stm32f4_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 stm32f4_i2c_msg {
+	u8	addr;
+	u32	count;
+	u8	*buf;
+	int	result;
+	bool	stop;
+};
+
+/**
+ * struct stm32f4_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
+ * @irq_event: interrupt event line for the controller
+ * @irq_error: interrupt error line for the controller
+ * @clk: hw i2c clock
+ * speed: I2C clock frequency of the controller. Standard or Fast only supported
+ * @msg: I2C transfer information
+ */
+struct stm32f4_i2c_dev {
+	struct i2c_adapter		adap;
+	struct device			*dev;
+	void __iomem			*base;
+	struct completion		complete;
+	int				irq_event;
+	int				irq_error;
+	struct clk			*clk;
+	int				speed;
+	struct stm32f4_i2c_msg		msg;
+};
+
+static struct stm32f4_i2c_timings i2c_timings[] = {
+	[STM32F4_I2C_SPEED_STANDARD] = {
+		.mul_ccr		= 1,
+		.min_ccr		= 4,
+		.duty			= 0,
+	},
+	[STM32F4_I2C_SPEED_FAST] = {
+		.mul_ccr		= 16,
+		.min_ccr		= 1,
+		.duty			= 1,
+	},
+};
+
+static inline void stm32f4_i2c_set_bits(void __iomem *reg, u32 mask)
+{
+	writel_relaxed(readl_relaxed(reg) | mask, reg);
+}
+
+static inline void stm32f4_i2c_clr_bits(void __iomem *reg, u32 mask)
+{
+	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
+}
+
+static void stm32f4_i2c_soft_reset(struct stm32f4_i2c_dev *i2c_dev)
+{
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR1;
+
+	stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_SWRST);
+	stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_SWRST);
+}
+
+static void stm32f4_i2c_disable_it(struct stm32f4_i2c_dev *i2c_dev)
+{
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_IRQ_MASK);
+}
+
+static void stm32f4_i2c_set_periph_clk_freq(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 clk_rate, cr2, freq;
+
+	cr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
+	cr2 &= ~STM32F4_I2C_CR2_FREQ_MASK;
+	clk_rate = clk_get_rate(i2c_dev->clk);
+	freq = clk_rate / MHZ_TO_HZ;
+	freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
+	cr2 |= STM32F4_I2C_CR2_FREQ(freq);
+	writel_relaxed(cr2, i2c_dev->base + STM32F4_I2C_CR2);
+}
+
+static void stm32f4_i2c_set_rise_time(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 trise, freq, cr2, val;
+
+	cr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
+	freq = cr2 & STM32F4_I2C_CR2_FREQ_MASK;
+
+	trise = readl_relaxed(i2c_dev->base + STM32F4_I2C_TRISE);
+	trise &= ~STM32F4_I2C_TRISE_VALUE_MASK;
+
+	/* Maximum rise time computation */
+	if (i2c_dev->speed == STM32F4_I2C_SPEED_STANDARD) {
+		trise |= STM32F4_I2C_TRISE_VALUE((freq + 1));
+	} else {
+		val = freq * FAST_MODE_MAX_RISE_TIME / STD_MODE_MAX_RISE_TIME;
+		trise |= STM32F4_I2C_TRISE_VALUE((val + 1));
+	}
+
+	writel_relaxed(trise, i2c_dev->base + STM32F4_I2C_TRISE);
+}
+
+static void stm32f4_i2c_set_speed_mode(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_timings *t = &i2c_timings[i2c_dev->speed];
+	u32 ccr, clk_rate;
+	int val;
+
+	ccr = readl_relaxed(i2c_dev->base + STM32F4_I2C_CCR);
+	ccr &= ~(STM32F4_I2C_CCR_FS | STM32F4_I2C_CCR_DUTY |
+		 STM32F4_I2C_CCR_CCR_MASK);
+
+	clk_rate = clk_get_rate(i2c_dev->clk);
+	val = clk_rate / MHZ_TO_HZ * t->mul_ccr;
+	if (val < t->min_ccr)
+		val = t->min_ccr;
+	ccr |= STM32F4_I2C_CCR_CCR(val);
+
+	if (t->duty)
+		ccr |= STM32F4_I2C_CCR_FS | STM32F4_I2C_CCR_DUTY;
+
+	writel_relaxed(ccr, i2c_dev->base + STM32F4_I2C_CCR);
+}
+
+static void stm32f4_i2c_set_filter(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 filter;
+
+	/* Enable analog noise filter and disable digital noise filter */
+	filter = readl_relaxed(i2c_dev->base + STM32F4_I2C_FLTR);
+	filter &= ~(STM32F4_I2C_FLTR_ANOFF | STM32F4_I2C_FLTR_DNF_MASK);
+	writel_relaxed(filter, i2c_dev->base + STM32F4_I2C_FLTR);
+}
+
+/**
+ * stm32f4_i2c_hw_config() - Prepare I2C block
+ * @i2c_dev: Controller's private data
+ */
+static void stm32f4_i2c_hw_config(struct stm32f4_i2c_dev *i2c_dev)
+{
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR1;
+
+	/* Disable I2C */
+	stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_PE);
+
+	stm32f4_i2c_set_periph_clk_freq(i2c_dev);
+
+	stm32f4_i2c_set_rise_time(i2c_dev);
+
+	stm32f4_i2c_set_speed_mode(i2c_dev);
+
+	stm32f4_i2c_set_filter(i2c_dev);
+
+	/* Enable I2C */
+	stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_PE);
+}
+
+static int stm32f4_i2c_wait_free_bus(struct stm32f4_i2c_dev *i2c_dev)
+{
+	u32 status;
+	int ret;
+
+	ret = readl_relaxed_poll_timeout(i2c_dev->base + STM32F4_I2C_SR2,
+					 status,
+					 !(status & STM32F4_I2C_SR2_BUSY),
+					 10, 1000);
+	if (ret) {
+		dev_err(i2c_dev->dev, "bus not free\n");
+		ret = -EBUSY;
+	}
+
+	return ret;
+}
+
+/**
+ * stm32f4_i2c_write_ byte() - Write a byte in the data register
+ * @i2c_dev: Controller's private data
+ * @byte: Data to write in the register
+ */
+static void stm32f4_i2c_write_byte(struct stm32f4_i2c_dev *i2c_dev, u8 byte)
+{
+	writel_relaxed(byte, i2c_dev->base + STM32F4_I2C_DR);
+}
+
+/**
+ * stm32f4_i2c_write_msg() - Fill the data register in write mode
+ * @i2c_dev: Controller's private data
+ *
+ * This function fills the data register with I2C transfer buffer
+ */
+static void stm32f4_i2c_write_msg(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+
+	stm32f4_i2c_write_byte(i2c_dev, *msg->buf++);
+	msg->count--;
+}
+
+static void stm32f4_i2c_read_msg(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	u32 rbuf;
+
+	rbuf = readl_relaxed(i2c_dev->base + STM32F4_I2C_DR);
+	*msg->buf++ = (u8)rbuf & 0xff;
+	msg->count--;
+}
+
+static void stm32f4_i2c_terminate_xfer(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	stm32f4_i2c_disable_it(i2c_dev);
+
+	reg = i2c_dev->base + STM32F4_I2C_CR1;
+	if (msg->stop)
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_STOP);
+	else
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_START);
+
+	complete(&i2c_dev->complete);
+}
+
+/**
+ * stm32f4_i2c_handle_write() - Handle FIFO empty interrupt in case of write
+ * @i2c_dev: Controller's private data
+ */
+static void stm32f4_i2c_handle_write(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	if (msg->count) {
+		stm32f4_i2c_write_msg(i2c_dev);
+		if (!msg->count) {
+			/* Disable BUF interrupt */
+			stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_ITBUFEN);
+		}
+	} else {
+		stm32f4_i2c_terminate_xfer(i2c_dev);
+	}
+}
+
+/**
+ * stm32f4_i2c_handle_read() - Handle FIFO empty interrupt in case of read
+ * @i2c_dev: Controller's private data
+ */
+static void stm32f4_i2c_handle_read(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
+
+	switch (msg->count) {
+	case 1:
+		stm32f4_i2c_disable_it(i2c_dev);
+		stm32f4_i2c_read_msg(i2c_dev);
+		complete(&i2c_dev->complete);
+		break;
+	case 2:
+	case 3:
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_ITBUFEN);
+		break;
+	default:
+		stm32f4_i2c_read_msg(i2c_dev);
+	}
+}
+
+/**
+ * stm32f4_i2c_handle_rx_btf() - Handle byte transfer finished interrupt
+ * in case of read
+ * @i2c_dev: Controller's private data
+ */
+static void stm32f4_i2c_handle_rx_btf(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg;
+	u32 mask;
+	int i;
+
+	switch (msg->count) {
+	case 2:
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		/* Generate STOP or REPSTART */
+		if (msg->stop)
+			stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_STOP);
+		else
+			stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_START);
+
+		/* Read two last data bytes */
+		for (i = 2; i > 0; i--)
+			stm32f4_i2c_read_msg(i2c_dev);
+
+		/* Disable EVT and ERR interrupt */
+		reg = i2c_dev->base + STM32F4_I2C_CR2;
+		mask = STM32F4_I2C_CR2_ITEVTEN | STM32F4_I2C_CR2_ITERREN;
+		stm32f4_i2c_clr_bits(reg, mask);
+
+		complete(&i2c_dev->complete);
+		break;
+	case 3:
+		/* Enable ACK and read data */
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_ACK);
+		stm32f4_i2c_read_msg(i2c_dev);
+		break;
+	default:
+		stm32f4_i2c_read_msg(i2c_dev);
+	}
+}
+
+/**
+ * stm32f4_i2c_handle_rx_addr() - Handle address matched interrupt in case of
+ * master receiver
+ * @i2c_dev: Controller's private data
+ */
+static void stm32f4_i2c_handle_rx_addr(struct stm32f4_i2c_dev *i2c_dev)
+{
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg;
+	u32 sr2;
+
+	switch (msg->count) {
+	case 0:
+		stm32f4_i2c_terminate_xfer(i2c_dev);
+		/* Clear ADDR flag */
+		sr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+		break;
+	case 1:
+		/*
+		 * Single byte reception:
+		 * Enable NACK, clear ADDR flag and generate STOP or RepSTART
+		 */
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_ACK);
+		sr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+		if (msg->stop)
+			stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_STOP);
+		else
+			stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_START);
+		break;
+	case 2:
+		/*
+		 * 2-byte reception:
+		 * Enable NACK and PEC Position Ack and clear ADDR flag
+		 */
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_ACK);
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_POS);
+		sr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+		break;
+
+	default:
+		/* N-byte reception: Enable ACK and clear ADDR flag */
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_ACK);
+		sr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+		break;
+	}
+}
+
+/**
+ * stm32f4_i2c_isr_event() - Interrupt routine for I2C bus event
+ * @irq: interrupt number
+ * @data: Controller's private data
+ */
+static irqreturn_t stm32f4_i2c_isr_event(int irq, void *data)
+{
+	struct stm32f4_i2c_dev *i2c_dev = data;
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg;
+	u32 real_status, possible_status, ien, sr2;
+	int flag;
+
+	ien = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
+	ien &= STM32F4_I2C_CR2_IRQ_MASK;
+	possible_status = 0;
+
+	/* Check possible status combinations */
+	if (ien & STM32F4_I2C_CR2_ITEVTEN) {
+		possible_status = STM32F4_I2C_SR1_ITEVTEN_MASK;
+		if (ien & STM32F4_I2C_CR2_ITBUFEN)
+			possible_status |= STM32F4_I2C_SR1_ITBUFEN_MASK;
+	}
+
+	real_status = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR1);
+
+	if (!(real_status & possible_status)) {
+		dev_dbg(i2c_dev->dev,
+			"spurious evt it (status=0x%08x, ien=0x%08x)\n",
+			real_status, ien);
+		return IRQ_NONE;
+	}
+
+	/* Use __fls() to check error bits first */
+	flag = __fls(real_status & possible_status);
+
+	switch (1 << flag) {
+	case STM32F4_I2C_SR1_SB:
+		stm32f4_i2c_write_byte(i2c_dev, msg->addr);
+		break;
+
+	case STM32F4_I2C_SR1_ADDR:
+		if (msg->addr & I2C_M_RD)
+			stm32f4_i2c_handle_rx_addr(i2c_dev);
+		else
+			sr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR2);
+
+		/* Enable ITBUF interrupts */
+		reg = i2c_dev->base + STM32F4_I2C_CR2;
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR2_ITBUFEN);
+		break;
+
+	case STM32F4_I2C_SR1_BTF:
+		if (msg->addr & I2C_M_RD)
+			stm32f4_i2c_handle_rx_btf(i2c_dev);
+		else
+			stm32f4_i2c_handle_write(i2c_dev);
+		break;
+
+	case STM32F4_I2C_SR1_TXE:
+		stm32f4_i2c_handle_write(i2c_dev);
+		break;
+
+	case STM32F4_I2C_SR1_RXNE:
+		stm32f4_i2c_handle_read(i2c_dev);
+		break;
+
+	default:
+		dev_err(i2c_dev->dev,
+			"evt it unhandled: status=0x%08x)\n", real_status);
+		return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * stm32f4_i2c_isr_error() - Interrupt routine for I2C bus error
+ * @irq: interrupt number
+ * @data: Controller's private data
+ */
+static irqreturn_t stm32f4_i2c_isr_error(int irq, void *data)
+{
+	struct stm32f4_i2c_dev *i2c_dev = data;
+	struct stm32f4_i2c_msg *msg = &i2c_dev->msg;
+	void __iomem *reg;
+	u32 real_status, possible_status, ien;
+	int flag;
+
+	ien = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
+	ien &= STM32F4_I2C_CR2_IRQ_MASK;
+	possible_status = 0;
+
+	/* Check possible status combinations */
+	if (ien & STM32F4_I2C_CR2_ITERREN)
+		possible_status = STM32F4_I2C_SR1_ITERREN_MASK;
+
+	real_status = readl_relaxed(i2c_dev->base + STM32F4_I2C_SR1);
+
+	if (!(real_status & possible_status)) {
+		dev_dbg(i2c_dev->dev,
+			"spurious err it (status=0x%08x, ien=0x%08x)\n",
+			real_status, ien);
+		return IRQ_NONE;
+	}
+
+	/* Use __fls() to check error bits first */
+	flag = __fls(real_status & possible_status);
+
+	switch (1 << flag) {
+	case STM32F4_I2C_SR1_BERR:
+		reg = i2c_dev->base + STM32F4_I2C_SR1;
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_SR1_BERR);
+		msg->result = -EIO;
+		break;
+
+	case STM32F4_I2C_SR1_ARLO:
+		reg = i2c_dev->base + STM32F4_I2C_SR1;
+		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_SR1_ARLO);
+		msg->result = -EAGAIN;
+		break;
+
+	case STM32F4_I2C_SR1_AF:
+		reg = i2c_dev->base + STM32F4_I2C_CR1;
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_STOP);
+		msg->result = -EIO;
+		break;
+
+	default:
+		dev_err(i2c_dev->dev,
+			"err it unhandled: status=0x%08x)\n", real_status);
+		return IRQ_NONE;
+	}
+
+	stm32f4_i2c_soft_reset(i2c_dev);
+	stm32f4_i2c_disable_it(i2c_dev);
+	complete(&i2c_dev->complete);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * stm32f4_i2c_xfer_msg() - Transfer a single I2C message
+ * @i2c_dev: Controller's private data
+ * @msg: I2C message to transfer
+ * @is_first: first message of the sequence
+ * @is_last: last message of the sequence
+ */
+static int stm32f4_i2c_xfer_msg(struct stm32f4_i2c_dev *i2c_dev,
+				struct i2c_msg *msg, bool is_first,
+				bool is_last)
+{
+	struct stm32f4_i2c_msg *f4_msg = &i2c_dev->msg;
+	void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR1;
+	unsigned long timeout;
+	u32 mask;
+	int ret;
+
+	f4_msg->addr = i2c_8bit_addr_from_msg(msg);
+	f4_msg->buf = msg->buf;
+	f4_msg->count = msg->len;
+	f4_msg->result = 0;
+	f4_msg->stop = is_last;
+
+	reinit_completion(&i2c_dev->complete);
+
+	/* Enable ITEVT and ITERR interrupts */
+	mask = STM32F4_I2C_CR2_ITEVTEN | STM32F4_I2C_CR2_ITERREN;
+	stm32f4_i2c_set_bits(i2c_dev->base + STM32F4_I2C_CR2, mask);
+
+	if (is_first) {
+		ret = stm32f4_i2c_wait_free_bus(i2c_dev);
+		if (ret)
+			return ret;
+
+		/* START generation */
+		stm32f4_i2c_set_bits(reg, STM32F4_I2C_CR1_START);
+	}
+
+	timeout = wait_for_completion_timeout(&i2c_dev->complete,
+					      i2c_dev->adap.timeout);
+	ret = f4_msg->result;
+
+	/* Disable PEC position Ack */
+	stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR1_POS);
+
+	if (!timeout)
+		ret = -ETIMEDOUT;
+
+	return ret;
+}
+
+/**
+ * stm32f4_i2c_xfer() - Transfer combined I2C message
+ * @i2c_adap: Adapter pointer to the controller
+ * @msgs: Pointer to data to be written.
+ * @num: Number of messages to be executed
+ */
+static int stm32f4_i2c_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg msgs[],
+			    int num)
+{
+	struct stm32f4_i2c_dev *i2c_dev = i2c_get_adapdata(i2c_adap);
+	int ret, i;
+
+	ret = clk_enable(i2c_dev->clk);
+	if (ret) {
+		dev_err(i2c_dev->dev, "Failed to enable clock\n");
+		return ret;
+	}
+
+	stm32f4_i2c_hw_config(i2c_dev);
+
+	for (i = 0; i < num && !ret; i++)
+		ret = stm32f4_i2c_xfer_msg(i2c_dev, &msgs[i], i == 0,
+					   i == num - 1);
+
+	clk_disable(i2c_dev->clk);
+
+	return (ret < 0) ? ret : i;
+}
+
+static u32 stm32f4_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm stm32f4_i2c_algo = {
+	.master_xfer = stm32f4_i2c_xfer,
+	.functionality = stm32f4_i2c_func,
+};
+
+static int stm32f4_i2c_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct stm32f4_i2c_dev *i2c_dev;
+	struct resource *res;
+	u32 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);
+
+	i2c_dev->irq_event = irq_of_parse_and_map(np, 0);
+	if (!i2c_dev->irq_event) {
+		dev_err(&pdev->dev, "IRQ missing or invalid\n");
+		return -EINVAL;
+	}
+
+	i2c_dev->irq_error = irq_of_parse_and_map(np, 1);
+	if (!i2c_dev->irq_error) {
+		dev_err(&pdev->dev, "IRQ 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(i2c_dev->clk);
+	if (ret) {
+		dev_err(i2c_dev->dev, "Failed to prepare 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 = STM32F4_I2C_SPEED_STANDARD;
+	ret = of_property_read_u32(np, "clock-frequency", &clk_rate);
+	if ((!ret) && (clk_rate == 400000))
+		i2c_dev->speed = STM32F4_I2C_SPEED_FAST;
+
+	i2c_dev->dev = &pdev->dev;
+
+	ret = devm_request_threaded_irq(&pdev->dev, i2c_dev->irq_event,
+					NULL, stm32f4_i2c_isr_event,
+					IRQF_ONESHOT, pdev->name, i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq %i\n",
+			i2c_dev->irq_error);
+		goto clk_free;
+	}
+
+	ret = devm_request_threaded_irq(&pdev->dev, i2c_dev->irq_error,
+					NULL, stm32f4_i2c_isr_error,
+					IRQF_ONESHOT, pdev->name, i2c_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to request irq %i\n",
+			i2c_dev->irq_error);
+		goto clk_free;
+	}
+
+	adap = &i2c_dev->adap;
+	i2c_set_adapdata(adap, i2c_dev);
+	snprintf(adap->name, sizeof(adap->name), "STM32 I2C(%pa)", &res->start);
+	adap->owner = THIS_MODULE;
+	adap->timeout = 2 * HZ;
+	adap->retries = 0;
+	adap->algo = &stm32f4_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)
+		goto clk_free;
+
+	platform_set_drvdata(pdev, i2c_dev);
+
+	dev_info(i2c_dev->dev, "STM32F4 I2C driver initialized\n");
+
+	return 0;
+
+clk_free:
+	clk_unprepare(i2c_dev->clk);
+	return ret;
+}
+
+static int stm32f4_i2c_remove(struct platform_device *pdev)
+{
+	struct stm32f4_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 stm32f4_i2c_match[] = {
+	{ .compatible = "st,stm32f4-i2c", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, stm32f4_i2c_match);
+
+static struct platform_driver stm32f4_i2c_driver = {
+	.driver = {
+		.name = "stm32f4-i2c",
+		.of_match_table = stm32f4_i2c_match,
+	},
+	.probe = stm32f4_i2c_probe,
+	.remove = stm32f4_i2c_remove,
+};
+
+module_platform_driver(stm32f4_i2c_driver);
+
+MODULE_AUTHOR("M'boumba Cedric Madianga <cedric.madianga@gmail.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32F4 I2C driver");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

[PATCH v5 2/5] i2c: Add STM32F4 I2C driver

[kbuild test robot]

Hi M'boumba,

[auto build test WARNING on wsa/i2c/for-next]
[also build test WARNING on v4.9-rc8 next-20161208]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/M-boumba-Cedric-Madianga/Add-support-for-the-STM32F4-I2C/20161208-173240
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next
config: i386-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All warnings (new ones prefixed by >>):

   In file included from include/linux/clk.h:16:0,
                    from drivers/i2c/busses/i2c-stm32f4.c:12:
   drivers/i2c/busses/i2c-stm32f4.c: In function 'stm32f4_i2c_set_periph_clk_freq':
   include/linux/kernel.h:749:16: warning: comparison of distinct pointer types lacks a cast
     (void) (&max1 == &max2);   \
                   ^
   include/linux/kernel.h:737:2: note: in definition of macro '__min'
     t1 min1 = (x);     \
     ^~
   include/linux/kernel.h:778:28: note: in expansion of macro 'min'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                               ^~~
>> include/linux/kernel.h:752:2: note: in expansion of macro '__max'
     __max(typeof(x), typeof(y),   \
     ^~~~~
>> include/linux/kernel.h:778:45: note: in expansion of macro 'max'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                                                ^~~
>> drivers/i2c/busses/i2c-stm32f4.c:201:9: note: in expansion of macro 'clamp'
     freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
            ^~~~~
   include/linux/kernel.h:749:16: warning: comparison of distinct pointer types lacks a cast
     (void) (&max1 == &max2);   \
                   ^
   include/linux/kernel.h:737:13: note: in definition of macro '__min'
     t1 min1 = (x);     \
                ^
   include/linux/kernel.h:778:28: note: in expansion of macro 'min'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                               ^~~
>> include/linux/kernel.h:752:2: note: in expansion of macro '__max'
     __max(typeof(x), typeof(y),   \
     ^~~~~
>> include/linux/kernel.h:778:45: note: in expansion of macro 'max'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                                                ^~~
>> drivers/i2c/busses/i2c-stm32f4.c:201:9: note: in expansion of macro 'clamp'
     freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
            ^~~~~
   include/linux/kernel.h:739:16: warning: comparison of distinct pointer types lacks a cast
     (void) (&min1 == &min2);   \
                   ^
   include/linux/kernel.h:742:2: note: in expansion of macro '__min'
     __min(typeof(x), typeof(y),   \
     ^~~~~
   include/linux/kernel.h:778:28: note: in expansion of macro 'min'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                               ^~~
>> drivers/i2c/busses/i2c-stm32f4.c:201:9: note: in expansion of macro 'clamp'
     freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
            ^~~~~

vim +/clamp +201 drivers/i2c/busses/i2c-stm32f4.c

   185	
   186	static void stm32f4_i2c_disable_it(struct stm32f4_i2c_dev *i2c_dev)
   187	{
   188		void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
   189	
   190		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_IRQ_MASK);
   191	}
   192	
   193	static void stm32f4_i2c_set_periph_clk_freq(struct stm32f4_i2c_dev *i2c_dev)
   194	{
   195		u32 clk_rate, cr2, freq;
   196	
   197		cr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
   198		cr2 &= ~STM32F4_I2C_CR2_FREQ_MASK;
   199		clk_rate = clk_get_rate(i2c_dev->clk);
   200		freq = clk_rate / MHZ_TO_HZ;
 > 201		freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
   202		cr2 |= STM32F4_I2C_CR2_FREQ(freq);
   203		writel_relaxed(cr2, i2c_dev->base + STM32F4_I2C_CR2);
   204	}
   205	
   206	static void stm32f4_i2c_set_rise_time(struct stm32f4_i2c_dev *i2c_dev)
   207	{
   208		u32 trise, freq, cr2, val;
   209	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
-------------- next part --------------
A non-text attachment was scrubbed...
Name: .config.gz
Type: application/gzip
Size: 56838 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20161208/776da99e/attachment-0001.gz>

[PATCH v5 2/5] i2c: Add STM32F4 I2C driver

[kbuild test robot]

Hi M'boumba,

[auto build test WARNING on wsa/i2c/for-next]
[also build test WARNING on v4.9-rc8 next-20161208]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/M-boumba-Cedric-Madianga/Add-support-for-the-STM32F4-I2C/20161208-173240
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next
config: openrisc-allyesconfig (attached as .config)
compiler: or32-linux-gcc (GCC) 4.5.1-or32-1.0rc1
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=openrisc 

All warnings (new ones prefixed by >>):

   drivers/i2c/busses/i2c-stm32f4.c: In function 'stm32f4_i2c_set_periph_clk_freq':
>> drivers/i2c/busses/i2c-stm32f4.c:201:9: warning: comparison of distinct pointer types lacks a cast
>> drivers/i2c/busses/i2c-stm32f4.c:201:9: warning: comparison of distinct pointer types lacks a cast
>> drivers/i2c/busses/i2c-stm32f4.c:201:9: warning: comparison of distinct pointer types lacks a cast

vim +201 drivers/i2c/busses/i2c-stm32f4.c

   185	
   186	static void stm32f4_i2c_disable_it(struct stm32f4_i2c_dev *i2c_dev)
   187	{
   188		void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
   189	
   190		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_IRQ_MASK);
   191	}
   192	
   193	static void stm32f4_i2c_set_periph_clk_freq(struct stm32f4_i2c_dev *i2c_dev)
   194	{
   195		u32 clk_rate, cr2, freq;
   196	
   197		cr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
   198		cr2 &= ~STM32F4_I2C_CR2_FREQ_MASK;
   199		clk_rate = clk_get_rate(i2c_dev->clk);
   200		freq = clk_rate / MHZ_TO_HZ;
 > 201		freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
   202		cr2 |= STM32F4_I2C_CR2_FREQ(freq);
   203		writel_relaxed(cr2, i2c_dev->base + STM32F4_I2C_CR2);
   204	}
   205	
   206	static void stm32f4_i2c_set_rise_time(struct stm32f4_i2c_dev *i2c_dev)
   207	{
   208		u32 trise, freq, cr2, val;
   209	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
-------------- next part --------------
A non-text attachment was scrubbed...
Name: .config.gz
Type: application/gzip
Size: 39528 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20161208/970e614a/attachment-0001.gz>

[PATCH v5 2/5] i2c: Add STM32F4 I2C driver

[kbuild test robot]

Hi M'boumba,

[auto build test WARNING on wsa/i2c/for-next]
[also build test WARNING on v4.9-rc8 next-20161208]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/M-boumba-Cedric-Madianga/Add-support-for-the-STM32F4-I2C/20161208-173240
base:   https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next
reproduce:
        # apt-get install sparse
        make ARCH=x86_64 allmodconfig
        make C=1 CF=-D__CHECK_ENDIAN__


sparse warnings: (new ones prefixed by >>)

   include/linux/compiler.h:253:8: sparse: attribute 'no_sanitize_address': unknown attribute
>> drivers/i2c/busses/i2c-stm32f4.c:201:16: sparse: incompatible types in comparison expression (different signedness)
>> drivers/i2c/busses/i2c-stm32f4.c:201:16: sparse: incompatible types in comparison expression (different signedness)
>> drivers/i2c/busses/i2c-stm32f4.c:201:16: sparse: incompatible types in comparison expression (different signedness)
   In file included from include/linux/clk.h:16:0,
                    from drivers/i2c/busses/i2c-stm32f4.c:12:
   drivers/i2c/busses/i2c-stm32f4.c: In function 'stm32f4_i2c_set_periph_clk_freq':
   include/linux/kernel.h:749:16: warning: comparison of distinct pointer types lacks a cast
     (void) (&max1 == &max2);   \
                   ^
   include/linux/kernel.h:737:2: note: in definition of macro '__min'
     t1 min1 = (x);     \
     ^~
   include/linux/kernel.h:778:28: note: in expansion of macro 'min'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                               ^~~
   include/linux/kernel.h:752:2: note: in expansion of macro '__max'
     __max(typeof(x), typeof(y),   \
     ^~~~~
   include/linux/kernel.h:778:45: note: in expansion of macro 'max'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                                                ^~~
   drivers/i2c/busses/i2c-stm32f4.c:201:9: note: in expansion of macro 'clamp'
     freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
            ^~~~~
   include/linux/kernel.h:749:16: warning: comparison of distinct pointer types lacks a cast
     (void) (&max1 == &max2);   \
                   ^
   include/linux/kernel.h:737:13: note: in definition of macro '__min'
     t1 min1 = (x);     \
                ^
   include/linux/kernel.h:778:28: note: in expansion of macro 'min'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                               ^~~
   include/linux/kernel.h:752:2: note: in expansion of macro '__max'
     __max(typeof(x), typeof(y),   \
     ^~~~~
   include/linux/kernel.h:778:45: note: in expansion of macro 'max'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                                                ^~~
   drivers/i2c/busses/i2c-stm32f4.c:201:9: note: in expansion of macro 'clamp'
     freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
            ^~~~~
   include/linux/kernel.h:739:16: warning: comparison of distinct pointer types lacks a cast
     (void) (&min1 == &min2);   \
                   ^
   include/linux/kernel.h:742:2: note: in expansion of macro '__min'
     __min(typeof(x), typeof(y),   \
     ^~~~~
   include/linux/kernel.h:778:28: note: in expansion of macro 'min'
    #define clamp(val, lo, hi) min((typeof(val))max(val, lo), hi)
                               ^~~
   drivers/i2c/busses/i2c-stm32f4.c:201:9: note: in expansion of macro 'clamp'
     freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
            ^~~~~

vim +201 drivers/i2c/busses/i2c-stm32f4.c

   185	
   186	static void stm32f4_i2c_disable_it(struct stm32f4_i2c_dev *i2c_dev)
   187	{
   188		void __iomem *reg = i2c_dev->base + STM32F4_I2C_CR2;
   189	
   190		stm32f4_i2c_clr_bits(reg, STM32F4_I2C_CR2_IRQ_MASK);
   191	}
   192	
   193	static void stm32f4_i2c_set_periph_clk_freq(struct stm32f4_i2c_dev *i2c_dev)
   194	{
   195		u32 clk_rate, cr2, freq;
   196	
   197		cr2 = readl_relaxed(i2c_dev->base + STM32F4_I2C_CR2);
   198		cr2 &= ~STM32F4_I2C_CR2_FREQ_MASK;
   199		clk_rate = clk_get_rate(i2c_dev->clk);
   200		freq = clk_rate / MHZ_TO_HZ;
 > 201		freq = clamp(freq, STM32F4_I2C_MIN_FREQ, STM32F4_I2C_MAX_FREQ);
   202		cr2 |= STM32F4_I2C_CR2_FREQ(freq);
   203		writel_relaxed(cr2, i2c_dev->base + STM32F4_I2C_CR2);
   204	}
   205	
   206	static void stm32f4_i2c_set_rise_time(struct stm32f4_i2c_dev *i2c_dev)
   207	{
   208		u32 trise, freq, cr2, val;
   209	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[PATCH v5 2/5] i2c: Add STM32F4 I2C driver

[Wolfram Sang]

Hi,

> +config I2C_STM32F4
> +	tristate "STMicroelectronics STM32F4 I2C support"
> +	depends on ARCH_STM32  || COMPILE_TEST

Double space.

> +#define STM32F4_I2C_MIN_FREQ		2
> +#define STM32F4_I2C_MAX_FREQ		42

Those two must be unsigned to fix the build error (e.g. 2U) reported by
build-bot.

Also, I get the following build warnings:

  CC      drivers/i2c/busses/i2c-stm32f4.o
drivers/i2c/busses/i2c-stm32f4.c: In function ?stm32f4_i2c_handle_rx_addr?:
drivers/i2c/busses/i2c-stm32f4.c:445:6: warning: variable ?sr2? set but not used [-Wunused-but-set-variable]
  u32 sr2;
      ^~~
drivers/i2c/busses/i2c-stm32f4.c: In function ?stm32f4_i2c_isr_event?:
drivers/i2c/busses/i2c-stm32f4.c:496:41: warning: variable ?sr2? set but not used [-Wunused-but-set-variable]
  u32 real_status, possible_status, ien, sr2;

I assume those are reads to clear the register, so we really don't need
to save the value in a variable.

Rest is looking good.

Thanks,

   Wolfram

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20161211/0379cc61/attachment.sig>

[PATCH v5 2/5] i2c: Add STM32F4 I2C driver

[M'boumba Cedric Madianga]

Hi Wolfram,

Thanks for your comments.
I will fix all of them + build errors reported by build-bot in the V6.

Best regards,

Cedric Madianga

2016-12-11 22:42 GMT+01:00 Wolfram Sang <wsa@the-dreams.de>:
> Hi,
>
>> +config I2C_STM32F4
>> +     tristate "STMicroelectronics STM32F4 I2C support"
>> +     depends on ARCH_STM32  || COMPILE_TEST
>
> Double space.
>
>> +#define STM32F4_I2C_MIN_FREQ         2
>> +#define STM32F4_I2C_MAX_FREQ         42
>
> Those two must be unsigned to fix the build error (e.g. 2U) reported by
> build-bot.
>
> Also, I get the following build warnings:
>
>   CC      drivers/i2c/busses/i2c-stm32f4.o
> drivers/i2c/busses/i2c-stm32f4.c: In function ?stm32f4_i2c_handle_rx_addr?:
> drivers/i2c/busses/i2c-stm32f4.c:445:6: warning: variable ?sr2? set but not used [-Wunused-but-set-variable]
>   u32 sr2;
>       ^~~
> drivers/i2c/busses/i2c-stm32f4.c: In function ?stm32f4_i2c_isr_event?:
> drivers/i2c/busses/i2c-stm32f4.c:496:41: warning: variable ?sr2? set but not used [-Wunused-but-set-variable]
>   u32 real_status, possible_status, ien, sr2;
>
> I assume those are reads to clear the register, so we really don't need
> to save the value in a variable.
>
> Rest is looking good.
>
> Thanks,
>
>    Wolfram
>

[PATCH v5 3/5] ARM: dts: Add I2C1 support for STM32F429 SoC

[M'boumba Cedric Madianga]

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 arch/arm/boot/dts/stm32f429.dtsi | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/arch/arm/boot/dts/stm32f429.dtsi b/arch/arm/boot/dts/stm32f429.dtsi
index 7de52ee..cbdece7 100644
--- a/arch/arm/boot/dts/stm32f429.dtsi
+++ b/arch/arm/boot/dts/stm32f429.dtsi
@@ -48,6 +48,7 @@
 #include "skeleton.dtsi"
 #include "armv7-m.dtsi"
 #include <dt-bindings/pinctrl/stm32f429-pinfunc.h>
+#include <dt-bindings/mfd/stm32f4-rcc.h>
 
 / {
 	clocks {
@@ -337,6 +338,16 @@
 					slew-rate = <2>;
 				};
 			};
+
+			i2c1_pins_b: i2c1 at 0 {
+				pins1 {
+					pinmux = <STM32F429_PB9_FUNC_I2C1_SDA>;
+					drive-open-drain;
+				};
+				pins2 {
+					pinmux = <STM32F429_PB6_FUNC_I2C1_SCL>;
+				};
+			};
 		};
 
 		rcc: rcc at 40023810 {
@@ -409,6 +420,18 @@
 			interrupts = <80>;
 			clocks = <&rcc 0 38>;
 		};
+
+		i2c1: i2c at 40005400 {
+			compatible = "st,stm32f4-i2c";
+			reg = <0x40005400 0x400>;
+			interrupts = <31>,
+				     <32>;
+			resets = <&rcc STM32F4_APB1_RESET(I2C1)>;
+			clocks = <&rcc 0 STM32F4_APB1_CLOCK(I2C1)>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			status = "disabled";
+		};
 	};
 };
 
-- 
1.9.1

[PATCH v5 4/5] ARM: dts: Add I2C1 support for STM32429 eval board

[M'boumba Cedric Madianga]

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 arch/arm/boot/dts/stm32429i-eval.dts | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/boot/dts/stm32429i-eval.dts b/arch/arm/boot/dts/stm32429i-eval.dts
index afb90bc..74e0045 100644
--- a/arch/arm/boot/dts/stm32429i-eval.dts
+++ b/arch/arm/boot/dts/stm32429i-eval.dts
@@ -141,3 +141,9 @@
 	pinctrl-names = "default";
 	status = "okay";
 };
+
+&i2c1 {
+	pinctrl-0 = <&i2c1_pins_b>;
+	pinctrl-names = "default";
+	status = "okay";
+};
-- 
1.9.1

[PATCH v5 4/5] ARM: dts: Add I2C1 support for STM32429 eval board

[Alexandre Torgue]

Hi Cedric,

On 12/08/2016 09:26 AM, M'boumba Cedric Madianga wrote:
> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
> ---
>  arch/arm/boot/dts/stm32429i-eval.dts | 6 ++++++
>  1 file changed, 6 insertions(+)
>
Can you change the commit header by: ARM: dts: stm32: Add I2C1 support 
for STM32429 eval board

thx
Alex

> diff --git a/arch/arm/boot/dts/stm32429i-eval.dts b/arch/arm/boot/dts/stm32429i-eval.dts
> index afb90bc..74e0045 100644
> --- a/arch/arm/boot/dts/stm32429i-eval.dts
> +++ b/arch/arm/boot/dts/stm32429i-eval.dts
> @@ -141,3 +141,9 @@
>  	pinctrl-names = "default";
>  	status = "okay";
>  };
> +
> +&i2c1 {
> +	pinctrl-0 = <&i2c1_pins_b>;
> +	pinctrl-names = "default";
> +	status = "okay";
> +};
>

[PATCH v5 4/5] ARM: dts: Add I2C1 support for STM32429 eval board

[M'boumba Cedric Madianga]

Hi Alex,


2016-12-08 9:39 GMT+01:00 Alexandre Torgue <alexandre.torgue@st.com>:
> Hi Cedric,
>
> On 12/08/2016 09:26 AM, M'boumba Cedric Madianga wrote:
>>
>> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
>> ---
>>  arch/arm/boot/dts/stm32429i-eval.dts | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
> Can you change the commit header by: ARM: dts: stm32: Add I2C1 support for
> STM32429 eval board
Ok, I will use this typo in the next version

>
> thx
> Alex
>
>
>> diff --git a/arch/arm/boot/dts/stm32429i-eval.dts
>> b/arch/arm/boot/dts/stm32429i-eval.dts
>> index afb90bc..74e0045 100644
>> --- a/arch/arm/boot/dts/stm32429i-eval.dts
>> +++ b/arch/arm/boot/dts/stm32429i-eval.dts
>> @@ -141,3 +141,9 @@
>>         pinctrl-names = "default";
>>         status = "okay";
>>  };
>> +
>> +&i2c1 {
>> +       pinctrl-0 = <&i2c1_pins_b>;
>> +       pinctrl-names = "default";
>> +       status = "okay";
>> +};
>>
>

[PATCH v5 5/5] ARM: configs: Add I2C support for STM32 defconfig

[M'boumba Cedric Madianga]

Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
---
 arch/arm/configs/stm32_defconfig | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
index e7b56d4..9494eaf 100644
--- a/arch/arm/configs/stm32_defconfig
+++ b/arch/arm/configs/stm32_defconfig
@@ -52,6 +52,9 @@ CONFIG_SERIAL_NONSTANDARD=y
 CONFIG_SERIAL_STM32=y
 CONFIG_SERIAL_STM32_CONSOLE=y
 # CONFIG_HW_RANDOM is not set
+CONFIG_I2C=y
+CONFIG_I2C_CHARDEV=y
+CONFIG_I2C_STM32F4=y
 # CONFIG_HWMON is not set
 # CONFIG_USB_SUPPORT is not set
 CONFIG_NEW_LEDS=y
-- 
1.9.1

[PATCH v5 5/5] ARM: configs: Add I2C support for STM32 defconfig

[Alexandre Torgue]

Hi Cedric,

On 12/08/2016 09:26 AM, M'boumba Cedric Madianga wrote:
> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
> ---
>  arch/arm/configs/stm32_defconfig | 3 +++
>  1 file changed, 3 insertions(+)
>
Can you change the commit header by ARM: configs: stm32: Add I2C support

Thx
alex




> diff --git a/arch/arm/configs/stm32_defconfig b/arch/arm/configs/stm32_defconfig
> index e7b56d4..9494eaf 100644
> --- a/arch/arm/configs/stm32_defconfig
> +++ b/arch/arm/configs/stm32_defconfig
> @@ -52,6 +52,9 @@ CONFIG_SERIAL_NONSTANDARD=y
>  CONFIG_SERIAL_STM32=y
>  CONFIG_SERIAL_STM32_CONSOLE=y
>  # CONFIG_HW_RANDOM is not set
> +CONFIG_I2C=y
> +CONFIG_I2C_CHARDEV=y
> +CONFIG_I2C_STM32F4=y
>  # CONFIG_HWMON is not set
>  # CONFIG_USB_SUPPORT is not set
>  CONFIG_NEW_LEDS=y
>

[PATCH v5 5/5] ARM: configs: Add I2C support for STM32 defconfig

[M'boumba Cedric Madianga]

Hi Alex,

2016-12-08 9:38 GMT+01:00 Alexandre Torgue <alexandre.torgue@st.com>:
> Hi Cedric,
>
> On 12/08/2016 09:26 AM, M'boumba Cedric Madianga wrote:
>>
>> Signed-off-by: M'boumba Cedric Madianga <cedric.madianga@gmail.com>
>> ---
>>  arch/arm/configs/stm32_defconfig | 3 +++
>>  1 file changed, 3 insertions(+)
>>
> Can you change the commit header by ARM: configs: stm32: Add I2C support
Ok, I will use this typo in the next version

>
> Thx
> alex
>
>
>
>
>
>> diff --git a/arch/arm/configs/stm32_defconfig
>> b/arch/arm/configs/stm32_defconfig
>> index e7b56d4..9494eaf 100644
>> --- a/arch/arm/configs/stm32_defconfig
>> +++ b/arch/arm/configs/stm32_defconfig
>> @@ -52,6 +52,9 @@ CONFIG_SERIAL_NONSTANDARD=y
>>  CONFIG_SERIAL_STM32=y
>>  CONFIG_SERIAL_STM32_CONSOLE=y
>>  # CONFIG_HW_RANDOM is not set
>> +CONFIG_I2C=y
>> +CONFIG_I2C_CHARDEV=y
>> +CONFIG_I2C_STM32F4=y
>>  # CONFIG_HWMON is not set
>>  # CONFIG_USB_SUPPORT is not set
>>  CONFIG_NEW_LEDS=y
>>
>