[PATCH resend 0/2] i2c: hix5hd2: add i2c controller driver

[PATCH resend 0/2] i2c: hix5hd2: add i2c controller driver

[Zhangfei Gao]

Resend: verified on 3.17-rc1

Wei Yan (2):
  i2c: hix5hd2: add devicetree documentation
  i2c: hix5hd2: add i2c controller driver

 .../devicetree/bindings/i2c/i2c-hix5hd2.txt        |   31 ++
 drivers/i2c/busses/Kconfig                         |   16 +
 drivers/i2c/busses/Makefile                        |    1 +
 drivers/i2c/busses/i2c-hix5hd2.c                   |  576 ++++++++++++++++++++
 4 files changed, 624 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-hix5hd2.txt
 create mode 100644 drivers/i2c/busses/i2c-hix5hd2.c

-- 
1.7.9.5

[PATCH resend 1/2] i2c: hix5hd2: add devicetree documentation

[Zhangfei Gao]

From: Wei Yan <sledge.yanwei@huawei.com>

Signed-off-by: Wei Yan <sledge.yanwei@huawei.com>
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
 .../devicetree/bindings/i2c/i2c-hix5hd2.txt        |   31 ++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-hix5hd2.txt

diff --git a/Documentation/devicetree/bindings/i2c/i2c-hix5hd2.txt b/Documentation/devicetree/bindings/i2c/i2c-hix5hd2.txt
new file mode 100644
index 0000000..2ecc8a7
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-hix5hd2.txt
@@ -0,0 +1,31 @@
+I2C for Hisilicon hix5hd2 chipset platforms (3716,3719,3798...)
+
+Required properties:
+- compatible: Must be "hisilicon,hix5hd2-i2c"
+  Specifically, the following versions of the chipset are supported:
+	  Hi3716CV200 (support six I2C module)
+	  Hi3719CV100 (support six I2C module)
+	  Hi3718CV100 (support six I2C module)
+	  Hi3719MV100 (support two I2C module)
+	  Hi3718MV100 (support two I2C module)
+- reg: physical base address of the controller and length of memory mapped
+     region.
+- interrupts: interrupt number to the cpu.
+- #address-cells = <1>;
+- #size-cells = <0>;
+- clocks: phandles to input clocks.
+
+Optional properties:
+- clock-frequency: Desired I2C bus frequency in Hz, otherwise defaults to 400000
+- Child nodes conforming to i2c bus binding
+
+Examples:
+I2C0 at f8b10000 {
+	compatible = "hisilicon,hix5hd2-i2c";
+	reg = <0xf8b10000 0x1000>;
+	interrupts = <0 38 4>;
+	clocks = <&clock HIX5HD2_I2C0_RST>;
+	#address-cells = <1>;
+	#size-cells = <0>;
+	status = "disabled";
+}
-- 
1.7.9.5

[PATCH resend 2/2] i2c: hix5hd2: add i2c controller driver

[Zhangfei Gao]

From: Wei Yan <sledge.yanwei@huawei.com>

I2C drivers for hix5hd2 soc series, including following chipset
Hi3716CV200, Hi3719CV100, Hi3718CV100, Hi3719MV100, Hi3718MV100.

Signed-off-by: Wei Yan <sledge.yanwei@huawei.com>
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
 drivers/i2c/busses/Kconfig       |   15 +
 drivers/i2c/busses/Makefile      |    1 +
 drivers/i2c/busses/i2c-hix5hd2.c |  573 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 589 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-hix5hd2.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 2ac87fa..6c66b9e 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -77,6 +77,21 @@ config I2C_AMD8111
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-amd8111.
 
+config I2C_HIX5HD2
+	tristate "Hix5hd2 high-speed I2C driver"
+	help
+	  Say Y here to include support for high-speed I2C controller in the
+	  Hisilicon based hix5hd2 SoCs. Specifically, the following versions
+	  of the chipset are supported:
+	  Hi3716CV200 (support six I2C module)
+	  Hi3719CV100 (support six I2C module)
+	  Hi3718CV100 (support six I2C module)
+	  Hi3719MV100 (support two I2C module)
+	  Hi3718MV100 (support two I2C module)
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-hix5hd2.
+
 config I2C_I801
 	tristate "Intel 82801 (ICH/PCH)"
 	depends on PCI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 49bf07e..9739938 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_I2C_EG20T)		+= i2c-eg20t.o
 obj-$(CONFIG_I2C_EXYNOS5)	+= i2c-exynos5.o
 obj-$(CONFIG_I2C_GPIO)		+= i2c-gpio.o
 obj-$(CONFIG_I2C_HIGHLANDER)	+= i2c-highlander.o
+obj-$(CONFIG_I2C_HIX5HD2)	+= i2c-hix5hd2.o
 obj-$(CONFIG_I2C_IBM_IIC)	+= i2c-ibm_iic.o
 obj-$(CONFIG_I2C_IMX)		+= i2c-imx.o
 obj-$(CONFIG_I2C_IOP3XX)	+= i2c-iop3xx.o
diff --git a/drivers/i2c/busses/i2c-hix5hd2.c b/drivers/i2c/busses/i2c-hix5hd2.c
new file mode 100644
index 0000000..2f6b87c
--- /dev/null
+++ b/drivers/i2c/busses/i2c-hix5hd2.c
@@ -0,0 +1,573 @@
+/*
+ * Copyright (c) 2014 Linaro Ltd.
+ * Copyright (c) 2014 Hisilicon Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * publishhed by the Free Software Foundation.
+ *
+ * Now only support 7 bit address.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+/* Register Map */
+#define HIX5I2C_CTRL		0x00
+#define HIX5I2C_COM		0x04
+#define HIX5I2C_ICR		0x08
+#define HIX5I2C_SR		0x0c
+#define HIX5I2C_SCL_H		0x10
+#define HIX5I2C_SCL_L		0x14
+#define HIX5I2C_TXR		0x18
+#define HIX5I2C_RXR		0x1c
+
+/* I2C_CTRL_REG */
+#define I2C_ENABLE		BIT(8)
+#define I2C_UNMASK_TOTAL	BIT(7)
+#define I2C_UNMASK_START	BIT(6)
+#define I2C_UNMASK_END		BIT(5)
+#define I2C_UNMASK_SEND		BIT(4)
+#define I2C_UNMASK_RECEIVE	BIT(3)
+#define I2C_UNMASK_ACK		BIT(2)
+#define I2C_UNMASK_ARBITRATE	BIT(1)
+#define I2C_UNMASK_OVER		BIT(0)
+#define I2C_UNMASK_ALL		(I2C_UNMASK_ACK | I2C_UNMASK_OVER)
+
+/* I2C_COM_REG */
+#define I2C_NO_ACK		BIT(4)
+#define I2C_START		BIT(3)
+#define I2C_READ		BIT(2)
+#define I2C_WRITE		BIT(1)
+#define I2C_STOP		BIT(0)
+
+/* I2C_ICR_REG */
+#define I2C_CLEAR_START		BIT(6)
+#define I2C_CLEAR_END		BIT(5)
+#define I2C_CLEAR_SEND		BIT(4)
+#define I2C_CLEAR_RECEIVE	BIT(3)
+#define I2C_CLEAR_ACK		BIT(2)
+#define I2C_CLEAR_ARBITRATE	BIT(1)
+#define I2C_CLEAR_OVER		BIT(0)
+#define I2C_CLEAR_ALL		(I2C_CLEAR_START | I2C_CLEAR_END | \
+				I2C_CLEAR_SEND | I2C_CLEAR_RECEIVE | \
+				I2C_CLEAR_ACK | I2C_CLEAR_ARBITRATE | \
+				I2C_CLEAR_OVER)
+
+/* I2C_SR_REG */
+#define I2C_BUSY		BIT(7)
+#define I2C_START_INTR		BIT(6)
+#define I2C_END_INTR		BIT(5)
+#define I2C_SEND_INTR		BIT(4)
+#define I2C_RECEIVE_INTR	BIT(3)
+#define I2C_ACK_INTR		BIT(2)
+#define I2C_ARBITRATE_INTR	BIT(1)
+#define I2C_OVER_INTR		BIT(0)
+
+/*
+ * Controller operating frequency, timing values for operation
+ * are calculated against this frequency
+ */
+#define HIX5I2C_NS_TX_CLOCK	100000		/* 100k */
+#define HIX5I2C_HS_TX_CLOCK	400000		/* 400k */
+
+#define HIX5I2C_READ_OPERATION	0x01
+#define HIX5I2C_WRITE_OPERATION	0xfe
+
+enum hix5hd2_i2c_state {
+	HIX5I2C_STAT_RW_ERR = -1,
+	HIX5I2C_STAT_INIT,
+	HIX5I2C_STAT_RW,
+	HIX5I2C_STAT_SND_STOP,
+	HIX5I2C_STAT_RW_SUCCESS,
+};
+
+enum hix5hd2_i2c_speed {
+	HIX5I2C_NORMAL_SPD,	/* Fast speed upto 1Mbps */
+	HIX5I2C_HIG_SPD,	/* High speed upto 3.4Mbps */
+};
+
+struct hix5hd2_i2c {
+	struct i2c_adapter adap;
+	struct i2c_msg	*msg;
+	unsigned int msg_ptr;	/* msg index */
+	unsigned int len;	/* msg length */
+	int stop;
+	struct completion msg_complete;
+
+	unsigned int irq;
+	void __iomem *regs;
+	struct clk *clk;
+	struct device *dev;
+	spinlock_t lock;	/* IRQ synchronization */
+
+	int err;
+	enum hix5hd2_i2c_state state;
+	enum hix5hd2_i2c_speed speed_mode;
+
+	/* Controller frequency */
+	unsigned int s_clock;
+};
+
+static u32 hix5hd2_i2c_clr_pend_irq(struct hix5hd2_i2c *i2c)
+{
+	u32 val = readl_relaxed(i2c->regs + HIX5I2C_SR);
+
+	writel_relaxed(val, i2c->regs + HIX5I2C_ICR);
+
+	return val;
+}
+
+static void hix5hd2_i2c_clr_all_irq(struct hix5hd2_i2c *i2c)
+{
+	writel_relaxed(I2C_CLEAR_ALL, i2c->regs + HIX5I2C_ICR);
+}
+
+static void hix5hd2_i2c_disable_irq(struct hix5hd2_i2c *i2c)
+{
+	writel_relaxed(0, i2c->regs + HIX5I2C_CTRL);
+}
+
+static void hix5hd2_i2c_enable_irq(struct hix5hd2_i2c *i2c)
+{
+	writel_relaxed(I2C_ENABLE | I2C_UNMASK_TOTAL | I2C_UNMASK_ALL,
+		       i2c->regs + HIX5I2C_CTRL);
+}
+
+static void hix5hd2_i2c_drv_setrate(struct hix5hd2_i2c *i2c)
+{
+	u32 rate, val;
+	u32 sclh, scll, sysclock;
+
+	/* close all i2c interrupt */
+	val = readl_relaxed(i2c->regs + HIX5I2C_CTRL);
+	writel_relaxed(val & (~I2C_UNMASK_TOTAL), i2c->regs + HIX5I2C_CTRL);
+
+	rate = i2c->s_clock;
+	sysclock = clk_get_rate(i2c->clk);
+	sclh = (sysclock / (rate * 2)) / 2 - 1;
+	writel_relaxed(sclh, i2c->regs + HIX5I2C_SCL_H);
+	scll = (sysclock / (rate * 2)) / 2 - 1;
+	writel_relaxed(scll, i2c->regs + HIX5I2C_SCL_L);
+
+	/* restore original interrupt*/
+	writel_relaxed(val, i2c->regs + HIX5I2C_CTRL);
+
+	dev_dbg(i2c->dev, "%s: sysclock=%d, rate=%d, sclh=%d, scll=%d\n",
+		__func__, sysclock, rate, sclh, scll);
+}
+
+static void hix5hd2_i2c_init(struct hix5hd2_i2c *i2c)
+{
+	hix5hd2_i2c_disable_irq(i2c);
+	hix5hd2_i2c_drv_setrate(i2c);
+	hix5hd2_i2c_clr_all_irq(i2c);
+	hix5hd2_i2c_enable_irq(i2c);
+}
+
+static void hix5hd2_i2c_reset(struct hix5hd2_i2c *i2c)
+{
+	clk_disable_unprepare(i2c->clk);
+	msleep(20);
+	clk_prepare_enable(i2c->clk);
+	hix5hd2_i2c_init(i2c);
+}
+
+static int hix5hd2_i2c_wait_bus_idle(struct hix5hd2_i2c *i2c)
+{
+	unsigned long stop_time;
+	u32 int_status;
+
+	/* wait for 100 milli seconds for the bus to be idle */
+	stop_time = jiffies + msecs_to_jiffies(100);
+	do {
+		int_status = hix5hd2_i2c_clr_pend_irq(i2c);
+		if (!(int_status & I2C_BUSY))
+			return 0;
+
+		usleep_range(50, 200);
+	} while (time_before(jiffies, stop_time));
+
+	return -EBUSY;
+}
+
+static void hix5hd2_rw_over(struct hix5hd2_i2c *i2c)
+{
+	if (HIX5I2C_STAT_SND_STOP == i2c->state)
+		dev_dbg(i2c->dev, "%s: rw and send stop over\n", __func__);
+	else
+		dev_dbg(i2c->dev, "%s: have not data to send\n", __func__);
+
+	i2c->state = HIX5I2C_STAT_RW_SUCCESS;
+	i2c->err = 0;
+}
+
+static void hix5hd2_rw_handle_stop(struct hix5hd2_i2c *i2c)
+{
+	if (i2c->stop) {
+		i2c->state = HIX5I2C_STAT_SND_STOP;
+		writel_relaxed(I2C_STOP, i2c->regs + HIX5I2C_COM);
+	} else {
+		hix5hd2_rw_over(i2c);
+	}
+}
+
+static void hix5hd2_read_handle(struct hix5hd2_i2c *i2c)
+{
+	if (1 == i2c->len) {
+		/* the last byte don't need send ACK */
+		writel_relaxed(I2C_READ | I2C_NO_ACK, i2c->regs + HIX5I2C_COM);
+	} else if (i2c->len > 1) {
+		/* if i2c master receive data will send ACK */
+		writel_relaxed(I2C_READ, i2c->regs + HIX5I2C_COM);
+	} else {
+		hix5hd2_rw_handle_stop(i2c);
+	}
+}
+
+static void hix5hd2_write_handle(struct hix5hd2_i2c *i2c)
+{
+	u8 data;
+
+	if (i2c->len > 0) {
+		data = i2c->msg->buf[i2c->msg_ptr++];
+		writel_relaxed(data, i2c->regs + HIX5I2C_TXR);
+		writel_relaxed(I2C_WRITE, i2c->regs + HIX5I2C_COM);
+	} else {
+		hix5hd2_rw_handle_stop(i2c);
+	}
+}
+
+static int hix5hd2_rw_preprocess(struct hix5hd2_i2c *i2c)
+{
+	u8 data;
+
+	if (HIX5I2C_STAT_INIT == i2c->state) {
+		i2c->state = HIX5I2C_STAT_RW;
+	} else if (HIX5I2C_STAT_RW == i2c->state) {
+		if (i2c->msg->flags & I2C_M_RD) {
+			data = readl_relaxed(i2c->regs + HIX5I2C_RXR);
+			i2c->msg->buf[i2c->msg_ptr++] = data;
+		}
+		i2c->len--;
+	} else {
+		dev_dbg(i2c->dev, "%s: error: i2c->state = %d, len = %d\n",
+			__func__, i2c->state, i2c->len);
+		return -EAGAIN;
+	}
+	return 0;
+}
+
+static irqreturn_t hix5hd2_i2c_irq(int irqno, void *dev_id)
+{
+	struct hix5hd2_i2c *i2c = dev_id;
+	u32 int_status;
+	int ret;
+
+	spin_lock(&i2c->lock);
+
+	int_status = hix5hd2_i2c_clr_pend_irq(i2c);
+
+	/* handle error */
+	if (int_status & I2C_ARBITRATE_INTR) {
+		/*Bus error */
+		dev_dbg(i2c->dev, "ARB bus loss\n");
+		i2c->err = -ENXIO;
+		i2c->state = HIX5I2C_STAT_RW_ERR;
+		goto stop;
+	} else if (int_status & I2C_ACK_INTR) {
+		/* ack error */
+		dev_dbg(i2c->dev, "No ACK from device\n");
+		i2c->err = -ENXIO;
+		i2c->state = HIX5I2C_STAT_RW_ERR;
+		goto stop;
+	}
+
+	if (int_status & I2C_OVER_INTR) {
+		if (i2c->len > 0) {
+			ret = hix5hd2_rw_preprocess(i2c);
+			if (ret) {
+				i2c->err = ret;
+				i2c->state = HIX5I2C_STAT_RW_ERR;
+				goto stop;
+			}
+			if (i2c->msg->flags & I2C_M_RD)
+				hix5hd2_read_handle(i2c);
+			else
+				hix5hd2_write_handle(i2c);
+		} else {
+			hix5hd2_rw_over(i2c);
+		}
+	}
+
+stop:
+	if ((HIX5I2C_STAT_RW_SUCCESS == i2c->state &&
+	     i2c->msg->len == i2c->msg_ptr) ||
+	    (HIX5I2C_STAT_RW_ERR == i2c->state)) {
+		hix5hd2_i2c_disable_irq(i2c);
+		hix5hd2_i2c_clr_pend_irq(i2c);
+		complete(&i2c->msg_complete);
+	}
+
+	spin_unlock(&i2c->lock);
+
+	return IRQ_HANDLED;
+}
+
+static void hix5hd2_i2c_message_start(struct hix5hd2_i2c *i2c, int stop)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&i2c->lock, flags);
+	hix5hd2_i2c_clr_all_irq(i2c);
+	hix5hd2_i2c_enable_irq(i2c);
+
+	if (i2c->msg->flags & I2C_M_RD)
+		writel_relaxed(i2c->msg->addr | HIX5I2C_READ_OPERATION,
+			       i2c->regs + HIX5I2C_TXR);
+	else
+		writel_relaxed(i2c->msg->addr & HIX5I2C_WRITE_OPERATION,
+			       i2c->regs + HIX5I2C_TXR);
+
+	writel_relaxed(I2C_WRITE | I2C_START, i2c->regs + HIX5I2C_COM);
+	spin_unlock_irqrestore(&i2c->lock, flags);
+}
+
+static int hix5hd2_i2c_xfer_msg(struct hix5hd2_i2c *i2c,
+				struct i2c_msg *msgs, int stop)
+{
+	unsigned long timeout;
+	int ret;
+
+	i2c->msg = msgs;
+	i2c->msg_ptr = 0;
+	i2c->len = i2c->msg->len;
+	i2c->stop = stop;
+	i2c->err = 0;
+	i2c->state = HIX5I2C_STAT_INIT;
+
+	reinit_completion(&i2c->msg_complete);
+	hix5hd2_i2c_message_start(i2c, stop);
+
+	timeout = wait_for_completion_timeout(&i2c->msg_complete,
+					      i2c->adap.timeout);
+	if (timeout == 0) {
+		i2c->state = HIX5I2C_STAT_RW_ERR;
+		i2c->err = -ETIMEDOUT;
+		dev_warn(i2c->dev, "%s timeout=%d\n",
+			 msgs->flags & I2C_M_RD ? "rx" : "tx",
+			 i2c->adap.timeout);
+	}
+	ret = i2c->state;
+
+	/*
+	 * If this is the last message to be transfered (stop == 1)
+	 * Then check if the bus can be brought back to idle.
+	 */
+	if (i2c->state == HIX5I2C_STAT_RW_SUCCESS && stop)
+		ret = hix5hd2_i2c_wait_bus_idle(i2c);
+
+	if (ret < 0)
+		hix5hd2_i2c_reset(i2c);
+
+	return i2c->err;
+}
+
+static int hix5hd2_i2c_xfer(struct i2c_adapter *adap,
+			    struct i2c_msg *msgs, int num)
+{
+	struct hix5hd2_i2c *i2c = i2c_get_adapdata(adap);
+	int i, ret, stop;
+
+	pm_runtime_get_sync(i2c->dev);
+
+	for (i = 0; i < num; i++, msgs++) {
+		stop = (i == num - 1);
+		ret = hix5hd2_i2c_xfer_msg(i2c, msgs, stop);
+		if (ret < 0)
+			goto out;
+	}
+
+	if (i == num) {
+		ret = num;
+	} else {
+		/* Only one message, cannot access the device */
+		if (i == 1)
+			ret = -EREMOTEIO;
+		else
+			ret = i;
+
+		dev_warn(i2c->dev, "xfer message failed\n");
+	}
+
+out:
+	pm_runtime_mark_last_busy(i2c->dev);
+	pm_runtime_put_autosuspend(i2c->dev);
+	return ret;
+}
+
+static u32 hix5hd2_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm hix5hd2_i2c_algorithm = {
+	.master_xfer		= hix5hd2_i2c_xfer,
+	.functionality		= hix5hd2_i2c_func,
+};
+
+static int hix5hd2_i2c_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct hix5hd2_i2c *i2c;
+	struct resource *mem;
+	unsigned int op_clock;
+	int ret;
+
+	i2c = devm_kzalloc(&pdev->dev, sizeof(struct hix5hd2_i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
+		/* use default value */
+		i2c->speed_mode = HIX5I2C_HIG_SPD;
+		i2c->s_clock = HIX5I2C_HS_TX_CLOCK;
+	} else {
+		if (op_clock >= HIX5I2C_HS_TX_CLOCK) {
+			i2c->speed_mode = HIX5I2C_HIG_SPD;
+			i2c->s_clock = HIX5I2C_HS_TX_CLOCK;
+		} else {
+			i2c->speed_mode = HIX5I2C_NORMAL_SPD;
+			i2c->s_clock = op_clock;
+		}
+	}
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	i2c->regs = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(i2c->regs))
+		return PTR_ERR(i2c->regs);
+
+	i2c->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(i2c->clk)) {
+		dev_err(&pdev->dev, "cannot get clock\n");
+		return -ENOENT;
+	}
+	clk_prepare_enable(i2c->clk);
+
+	i2c->irq = platform_get_irq(pdev, 0);
+	if (i2c->irq <= 0) {
+		dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n");
+		ret = -EINVAL;
+		goto err_clk;
+	}
+
+	strlcpy(i2c->adap.name, "hix5hd2-i2c", sizeof(i2c->adap.name));
+	i2c->dev = &pdev->dev;
+	i2c->adap.owner   = THIS_MODULE;
+	i2c->adap.algo	  = &hix5hd2_i2c_algorithm;
+	i2c->adap.retries = 3;
+	i2c->adap.dev.of_node = np;
+	i2c->adap.algo_data = i2c;
+	i2c->adap.dev.parent = &pdev->dev;
+	i2c_set_adapdata(&i2c->adap, i2c);
+	platform_set_drvdata(pdev, i2c);
+	spin_lock_init(&i2c->lock);
+	init_completion(&i2c->msg_complete);
+
+	hix5hd2_i2c_init(i2c);
+
+	ret = devm_request_irq(&pdev->dev, i2c->irq, hix5hd2_i2c_irq,
+			       IRQF_NO_SUSPEND | IRQF_ONESHOT,
+			       dev_name(&pdev->dev), i2c);
+	if (ret != 0) {
+		dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", i2c->irq);
+		goto err_clk;
+	}
+
+	ret = i2c_add_adapter(&i2c->adap);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+		goto err_clk;
+	}
+
+	pm_suspend_ignore_children(&pdev->dev, true);
+	pm_runtime_set_autosuspend_delay(i2c->dev, MSEC_PER_SEC);
+	pm_runtime_use_autosuspend(i2c->dev);
+	pm_runtime_set_active(i2c->dev);
+	pm_runtime_enable(i2c->dev);
+
+	return ret;
+
+err_clk:
+	clk_disable_unprepare(i2c->clk);
+	return ret;
+}
+
+static int hix5hd2_i2c_remove(struct platform_device *pdev)
+{
+	struct hix5hd2_i2c *i2c = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&i2c->adap);
+	pm_runtime_disable(i2c->dev);
+	pm_runtime_set_suspended(i2c->dev);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int hix5hd2_i2c_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct hix5hd2_i2c *i2c = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(i2c->clk);
+
+	return 0;
+}
+
+static int hix5hd2_i2c_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct hix5hd2_i2c *i2c = platform_get_drvdata(pdev);
+
+	clk_prepare_enable(i2c->clk);
+	hix5hd2_i2c_init(i2c);
+
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops hix5hd2_i2c_pm_ops = {
+	SET_PM_RUNTIME_PM_OPS(hix5hd2_i2c_runtime_suspend,
+			      hix5hd2_i2c_runtime_resume,
+			      NULL)
+};
+
+static const struct of_device_id hix5hd2_i2c_match[] = {
+	{ .compatible = "hisilicon,hix5hd2-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, hix5hd2_i2c_match);
+
+static struct platform_driver hix5hd2_i2c_driver = {
+	.probe		= hix5hd2_i2c_probe,
+	.remove		= hix5hd2_i2c_remove,
+	.driver		= {
+		.name	= "hix5hd2-i2c",
+		.pm	= &hix5hd2_i2c_pm_ops,
+		.of_match_table = hix5hd2_i2c_match,
+	},
+};
+
+module_platform_driver(hix5hd2_i2c_driver);
+
+MODULE_DESCRIPTION("Hix5hd2 I2C Bus driver");
+MODULE_AUTHOR("Wei Yan <sledge.yanwei@huawei.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-hix5hd2");
-- 
1.7.9.5

[PATCH resend 2/2] i2c: hix5hd2: add i2c controller driver

[Wolfram Sang]

Hi,

thanks for the submission.

> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-hix5hd2.c
> @@ -0,0 +1,573 @@
> +/*
> + * Copyright (c) 2014 Linaro Ltd.
> + * Copyright (c) 2014 Hisilicon Limited.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * publishhed by the Free Software Foundation.

"publishhed"

> + *
> + * Now only support 7 bit address.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/io.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>

I think there should be at least of.h, too.

> +struct hix5hd2_i2c {
> +	struct i2c_adapter adap;
> +	struct i2c_msg	*msg;
> +	unsigned int msg_ptr;	/* msg index */

Comment seems wrong. It looks to me as the msg buffer index. If so, the
variable name is also confusing.

> +	unsigned int len;	/* msg length */
> +	int stop;
> +	struct completion msg_complete;
> +
> +	unsigned int irq;

That can be a local variable.

> +	void __iomem *regs;
> +	struct clk *clk;
> +	struct device *dev;
> +	spinlock_t lock;	/* IRQ synchronization */
> +
> +	int err;
> +	enum hix5hd2_i2c_state state;
> +	enum hix5hd2_i2c_speed speed_mode;

Where is this needed?

> +
> +	/* Controller frequency */
> +	unsigned int s_clock;
> +};
> +
> +static void hix5hd2_i2c_drv_setrate(struct hix5hd2_i2c *i2c)
> +{
> +	u32 rate, val;
> +	u32 sclh, scll, sysclock;
> +
> +	/* close all i2c interrupt */
> +	val = readl_relaxed(i2c->regs + HIX5I2C_CTRL);
> +	writel_relaxed(val & (~I2C_UNMASK_TOTAL), i2c->regs + HIX5I2C_CTRL);
> +
> +	rate = i2c->s_clock;
> +	sysclock = clk_get_rate(i2c->clk);
> +	sclh = (sysclock / (rate * 2)) / 2 - 1;
> +	writel_relaxed(sclh, i2c->regs + HIX5I2C_SCL_H);
> +	scll = (sysclock / (rate * 2)) / 2 - 1;

scll and sclh use the same formula? Have you measured the setup
frequency with a scope?

> +	writel_relaxed(scll, i2c->regs + HIX5I2C_SCL_L);
> +
> +	/* restore original interrupt*/
> +	writel_relaxed(val, i2c->regs + HIX5I2C_CTRL);
> +
> +	dev_dbg(i2c->dev, "%s: sysclock=%d, rate=%d, sclh=%d, scll=%d\n",
> +		__func__, sysclock, rate, sclh, scll);
> +}
> +
> +static void hix5hd2_rw_over(struct hix5hd2_i2c *i2c)
> +{
> +	if (HIX5I2C_STAT_SND_STOP == i2c->state)

To be honest, I don't like having the constant on the left side. It
is far easier to read if they are on the right side. Plus, we have gcc
warnings to prevent the "=" and "==" mistake. Please switch them around
in this driver.

> +		dev_dbg(i2c->dev, "%s: rw and send stop over\n", __func__);
> +	else
> +		dev_dbg(i2c->dev, "%s: have not data to send\n", __func__);
> +
> +	i2c->state = HIX5I2C_STAT_RW_SUCCESS;
> +	i2c->err = 0;
> +}
> +

...

> +	/* handle error */
> +	if (int_status & I2C_ARBITRATE_INTR) {
> +		/*Bus error */

Space missing in front of "Bus". If this is an arbitration lost error,
then please use -EAGAIN. Check Documentation/i2c/fault-codes for the
convention.

> +		dev_dbg(i2c->dev, "ARB bus loss\n");
> +		i2c->err = -ENXIO;
> +		i2c->state = HIX5I2C_STAT_RW_ERR;
> +		goto stop;
> +	} else if (int_status & I2C_ACK_INTR) {
> +		/* ack error */
> +		dev_dbg(i2c->dev, "No ACK from device\n");
> +		i2c->err = -ENXIO;
> +		i2c->state = HIX5I2C_STAT_RW_ERR;
> +		goto stop;
> +	}
> +
> +static void hix5hd2_i2c_message_start(struct hix5hd2_i2c *i2c, int stop)
> +{
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(&i2c->lock, flags);
> +	hix5hd2_i2c_clr_all_irq(i2c);
> +	hix5hd2_i2c_enable_irq(i2c);
> +
> +	if (i2c->msg->flags & I2C_M_RD)
> +		writel_relaxed(i2c->msg->addr | HIX5I2C_READ_OPERATION,
> +			       i2c->regs + HIX5I2C_TXR);
> +	else
> +		writel_relaxed(i2c->msg->addr & HIX5I2C_WRITE_OPERATION,
> +			       i2c->regs + HIX5I2C_TXR);

??? Does this really work? i2c->msg->addr should be left shifted by 1?

> +
> +	writel_relaxed(I2C_WRITE | I2C_START, i2c->regs + HIX5I2C_COM);
> +	spin_unlock_irqrestore(&i2c->lock, flags);
> +}
> +
> +static int hix5hd2_i2c_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct hix5hd2_i2c *i2c;
> +	struct resource *mem;
> +	unsigned int op_clock;
> +	int ret;
> +
> +	i2c = devm_kzalloc(&pdev->dev, sizeof(struct hix5hd2_i2c), GFP_KERNEL);
> +	if (!i2c)
> +		return -ENOMEM;
> +
> +	if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
> +		/* use default value */
> +		i2c->speed_mode = HIX5I2C_HIG_SPD;
> +		i2c->s_clock = HIX5I2C_HS_TX_CLOCK;

Please use 100kHz as the default. This is the speed devices should
support. 400kHz is optional. And I think 100000 is easier to read than a
define.

> +	} else {
> +		if (op_clock >= HIX5I2C_HS_TX_CLOCK) {
> +			i2c->speed_mode = HIX5I2C_HIG_SPD;
> +			i2c->s_clock = HIX5I2C_HS_TX_CLOCK;

So, if the speed is bigger than 400kHz, it will be capped down to
400kHz? Is that true? Then, the user should be informed about that.

> +		} else {
> +			i2c->speed_mode = HIX5I2C_NORMAL_SPD;
> +			i2c->s_clock = op_clock;
> +		}
> +	}
> +

...

> +	i2c->adap.owner   = THIS_MODULE;
> +	i2c->adap.algo	  = &hix5hd2_i2c_algorithm;

Single space as indentation.

Thanks,

   Wolfram

[PATCH resend 2/2] i2c: hix5hd2: add i2c controller driver

[zhangfei]

Thanks Wolfram for the careful review

On 09/20/2014 01:18 AM, Wolfram Sang wrote:
> Hi,
>
> thanks for the submission.
>
>> --- /dev/null
>> +++ b/drivers/i2c/busses/i2c-hix5hd2.c
>> @@ -0,0 +1,573 @@
>> +/*
>> + * Copyright (c) 2014 Linaro Ltd.
>> + * Copyright (c) 2014 Hisilicon Limited.
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * publishhed by the Free Software Foundation.
>
> "publishhed"
OK.
>
>> + *
>> + * Now only support 7 bit address.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/delay.h>
>> +#include <linux/i2c.h>
>> +#include <linux/io.h>
>> +#include <linux/interrupt.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/pm_runtime.h>
>
> I think there should be at least of.h, too.
The of.h is already in i2c.h
include/linux/i2c.h:33:#include <linux/of.h>
>
>> +struct hix5hd2_i2c {
>> +	struct i2c_adapter adap;
>> +	struct i2c_msg	*msg;
>> +	unsigned int msg_ptr;	/* msg index */
>
> Comment seems wrong. It looks to me as the msg buffer index. If so, the
> variable name is also confusing.
Change to msg_idx & msg_len.
>
>> +	unsigned int len;	/* msg length */
>> +	int stop;
>> +	struct completion msg_complete;
>> +
>> +	unsigned int irq;
>
> That can be a local variable.
Yes
>
>> +	void __iomem *regs;
>> +	struct clk *clk;
>> +	struct device *dev;
>> +	spinlock_t lock;	/* IRQ synchronization */
>> +
>> +	int err;
>> +	enum hix5hd2_i2c_state state;
>> +	enum hix5hd2_i2c_speed speed_mode;
>
> Where is this needed?
will remove
>
>> +
>> +	/* Controller frequency */
>> +	unsigned int s_clock;
>> +};
>> +
>> +static void hix5hd2_i2c_drv_setrate(struct hix5hd2_i2c *i2c)
>> +{
>> +	u32 rate, val;
>> +	u32 sclh, scll, sysclock;
>> +
>> +	/* close all i2c interrupt */
>> +	val = readl_relaxed(i2c->regs + HIX5I2C_CTRL);
>> +	writel_relaxed(val & (~I2C_UNMASK_TOTAL), i2c->regs + HIX5I2C_CTRL);
>> +
>> +	rate = i2c->s_clock;
>> +	sysclock = clk_get_rate(i2c->clk);
>> +	sclh = (sysclock / (rate * 2)) / 2 - 1;
>> +	writel_relaxed(sclh, i2c->regs + HIX5I2C_SCL_H);
>> +	scll = (sysclock / (rate * 2)) / 2 - 1;
>
> scll and sclh use the same formula? Have you measured the setup
> frequency with a scope?
Yes, it is confusing, will use the same vector scl instead.
The value is same means sclk high voltage and low voltage keep same time.
>
>> +	writel_relaxed(scll, i2c->regs + HIX5I2C_SCL_L);
>> +
>> +	/* restore original interrupt*/
>> +	writel_relaxed(val, i2c->regs + HIX5I2C_CTRL);
>> +
>> +	dev_dbg(i2c->dev, "%s: sysclock=%d, rate=%d, sclh=%d, scll=%d\n",
>> +		__func__, sysclock, rate, sclh, scll);
>> +}
>> +
>> +static void hix5hd2_rw_over(struct hix5hd2_i2c *i2c)
>> +{
>> +	if (HIX5I2C_STAT_SND_STOP == i2c->state)
>
> To be honest, I don't like having the constant on the left side. It
> is far easier to read if they are on the right side. Plus, we have gcc
> warnings to prevent the "=" and "==" mistake. Please switch them around
> in this driver.
Got it.
>
>> +		dev_dbg(i2c->dev, "%s: rw and send stop over\n", __func__);
>> +	else
>> +		dev_dbg(i2c->dev, "%s: have not data to send\n", __func__);
>> +
>> +	i2c->state = HIX5I2C_STAT_RW_SUCCESS;
>> +	i2c->err = 0;
>> +}
>> +
>
> ...
>
>> +	/* handle error */
>> +	if (int_status & I2C_ARBITRATE_INTR) {
>> +		/*Bus error */
>
> Space missing in front of "Bus". If this is an arbitration lost error,
> then please use -EAGAIN. Check Documentation/i2c/fault-codes for the
> convention.
OK.
>
>> +		dev_dbg(i2c->dev, "ARB bus loss\n");
>> +		i2c->err = -ENXIO;
>> +		i2c->state = HIX5I2C_STAT_RW_ERR;
>> +		goto stop;
>> +	} else if (int_status & I2C_ACK_INTR) {
>> +		/* ack error */
>> +		dev_dbg(i2c->dev, "No ACK from device\n");
>> +		i2c->err = -ENXIO;
>> +		i2c->state = HIX5I2C_STAT_RW_ERR;
>> +		goto stop;
>> +	}
>> +
>> +static void hix5hd2_i2c_message_start(struct hix5hd2_i2c *i2c, int stop)
>> +{
>> +	unsigned long flags;
>> +
>> +	spin_lock_irqsave(&i2c->lock, flags);
>> +	hix5hd2_i2c_clr_all_irq(i2c);
>> +	hix5hd2_i2c_enable_irq(i2c);
>> +
>> +	if (i2c->msg->flags & I2C_M_RD)
>> +		writel_relaxed(i2c->msg->addr | HIX5I2C_READ_OPERATION,
>> +			       i2c->regs + HIX5I2C_TXR);
>> +	else
>> +		writel_relaxed(i2c->msg->addr & HIX5I2C_WRITE_OPERATION,
>> +			       i2c->regs + HIX5I2C_TXR);
>
> ??? Does this really work? i2c->msg->addr should be left shifted by 1?

Double checked, it is because the test applictaion do the left shift.
Yes, will do the left shift by 1.
>
>> +
>> +	writel_relaxed(I2C_WRITE | I2C_START, i2c->regs + HIX5I2C_COM);
>> +	spin_unlock_irqrestore(&i2c->lock, flags);
>> +}
>> +
>> +static int hix5hd2_i2c_probe(struct platform_device *pdev)
>> +{
>> +	struct device_node *np = pdev->dev.of_node;
>> +	struct hix5hd2_i2c *i2c;
>> +	struct resource *mem;
>> +	unsigned int op_clock;
>> +	int ret;
>> +
>> +	i2c = devm_kzalloc(&pdev->dev, sizeof(struct hix5hd2_i2c), GFP_KERNEL);
>> +	if (!i2c)
>> +		return -ENOMEM;
>> +
>> +	if (of_property_read_u32(np, "clock-frequency", &op_clock)) {
>> +		/* use default value */
>> +		i2c->speed_mode = HIX5I2C_HIG_SPD;
>> +		i2c->s_clock = HIX5I2C_HS_TX_CLOCK;
>
> Please use 100kHz as the default. This is the speed devices should
> support. 400kHz is optional. And I think 100000 is easier to read than a
> define.
OK.
>
>> +	} else {
>> +		if (op_clock >= HIX5I2C_HS_TX_CLOCK) {
>> +			i2c->speed_mode = HIX5I2C_HIG_SPD;
>> +			i2c->s_clock = HIX5I2C_HS_TX_CLOCK;
>
> So, if the speed is bigger than 400kHz, it will be capped down to
> 400kHz? Is that true? Then, the user should be informed about that.
Will add dev_warn to notify.
>
>> +		} else {
>> +			i2c->speed_mode = HIX5I2C_NORMAL_SPD;
>> +			i2c->s_clock = op_clock;
>> +		}
>> +	}
>> +
>
> ...
>
>> +	i2c->adap.owner   = THIS_MODULE;
>> +	i2c->adap.algo	  = &hix5hd2_i2c_algorithm;
>
> Single space as indentation.
Got it.

Thanks

[PATCH resend 2/2] i2c: hix5hd2: add i2c controller driver

[Wolfram Sang]

> >>+#include <linux/clk.h>
> >>+#include <linux/delay.h>
> >>+#include <linux/i2c.h>
> >>+#include <linux/io.h>
> >>+#include <linux/interrupt.h>
> >>+#include <linux/module.h>
> >>+#include <linux/platform_device.h>
> >>+#include <linux/pm_runtime.h>
> >
> >I think there should be at least of.h, too.
> The of.h is already in i2c.h
> include/linux/i2c.h:33:#include <linux/of.h>

Please add it nonetheless, because you use e.g. of_property_read_u32()
directly. That makes you independet of changes to i2c.h.

> >>+	rate = i2c->s_clock;
> >>+	sysclock = clk_get_rate(i2c->clk);
> >>+	sclh = (sysclock / (rate * 2)) / 2 - 1;
> >>+	writel_relaxed(sclh, i2c->regs + HIX5I2C_SCL_H);
> >>+	scll = (sysclock / (rate * 2)) / 2 - 1;
> >
> >scll and sclh use the same formula? Have you measured the setup
> >frequency with a scope?
> Yes, it is confusing, will use the same vector scl instead.
> The value is same means sclk high voltage and low voltage keep same time.

OK.

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[PATCH resend 0/2] i2c: hix5hd2: add i2c controller driver

[Zhangfei Gao]

On 26 August 2014 13:25, Zhangfei Gao <zhangfei.gao@linaro.org> wrote:
> Resend: verified on 3.17-rc1
>
> Wei Yan (2):
>   i2c: hix5hd2: add devicetree documentation
>   i2c: hix5hd2: add i2c controller driver
>
>  .../devicetree/bindings/i2c/i2c-hix5hd2.txt        |   31 ++
>  drivers/i2c/busses/Kconfig                         |   16 +
>  drivers/i2c/busses/Makefile                        |    1 +
>  drivers/i2c/busses/i2c-hix5hd2.c                   |  576 ++++++++++++++++++++
>  4 files changed, 624 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/i2c/i2c-hix5hd2.txt
>  create mode 100644 drivers/i2c/busses/i2c-hix5hd2.c
>

Any comments, thanks a lot.