[PATCH v2 0/2] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform

[PATCH v2 0/2] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform

[Masahiro Yamada]

This series adds two I2C controller drivers.
(they are completely different IPs.)

The first one is a very simple FIFO-less I2C controller,
which is used on some older UniPhier SoCs.

The other one is higher-performance I2C controller with TX/RX FIFO,
used on newer UniPhier SoCs.


Changes in v2:
  - Delete if-block after platform_get_resource()
  - Add I2C_FUNC_SMBUS_EMUL to functionality
  - Add bindings document
  - Add entry to MAINTAINERS
  - Delete if-block after platform_get_resource()
  - Add I2C_FUNC_SMBUS_EMUL to functionality
  - Add bindings document
  - Fix a typo in a comment block

Masahiro Yamada (2):
  i2c: uniphier: add UniPhier FIFO-less I2C driver
  i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver

 .../devicetree/bindings/i2c/i2c-uniphier-f.txt     |  25 +
 .../devicetree/bindings/i2c/i2c-uniphier.txt       |  25 +
 MAINTAINERS                                        |   1 +
 drivers/i2c/busses/Kconfig                         |  16 +
 drivers/i2c/busses/Makefile                        |   2 +
 drivers/i2c/busses/i2c-uniphier-f.c                | 584 +++++++++++++++++++++
 drivers/i2c/busses/i2c-uniphier.c                  | 441 ++++++++++++++++
 7 files changed, 1094 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
 create mode 100644 drivers/i2c/busses/i2c-uniphier-f.c
 create mode 100644 drivers/i2c/busses/i2c-uniphier.c

-- 
1.9.1

[PATCH v2 1/2] i2c: uniphier: add UniPhier FIFO-less I2C driver

[Masahiro Yamada]

Add support for on-chip I2C controller used on old UniPhier SoCs
such as PH1-LD4, PH1-sLD8, etc.  This adapter is so simple that
it has no FIFO in it.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v2:
  - Delete if-block after platform_get_resource()
  - Add I2C_FUNC_SMBUS_EMUL to functionality
  - Add bindings document
  - Add entry to MAINTAINERS

 .../devicetree/bindings/i2c/i2c-uniphier.txt       |  25 ++
 MAINTAINERS                                        |   1 +
 drivers/i2c/busses/Kconfig                         |   8 +
 drivers/i2c/busses/Makefile                        |   1 +
 drivers/i2c/busses/i2c-uniphier.c                  | 441 +++++++++++++++++++++
 5 files changed, 476 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
 create mode 100644 drivers/i2c/busses/i2c-uniphier.c

diff --git a/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt b/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
new file mode 100644
index 0000000..26f9d95
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
@@ -0,0 +1,25 @@
+UniPhier I2C controller (FIFO-less)
+
+Required properties:
+- compatible: should be "socionext,uniphier-i2c".
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+- reg: offset and length of the register set for the device.
+- interrupts: a single interrupt specifier.
+- clocks: phandle to the input clock.
+
+Optional properties:
+- clock-frequency: desired I2C bus frequency in Hz.  The maximum supported
+  value is 400000.  Defaults to 100000 if not specified.
+
+Examples:
+
+	i2c0: i2c@58400000 {
+		compatible = "socionext,uniphier-i2c";
+		reg = <0x58400000 0x40>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupts = <0 41 1>;
+		clocks = <&i2c_clk>;
+		clock-frequency = <100000>;
+	};
diff --git a/MAINTAINERS b/MAINTAINERS
index fb7d2e4..b21c456 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1607,6 +1607,7 @@ L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:	Maintained
 F:	arch/arm/boot/dts/uniphier*
 F:	arch/arm/mach-uniphier/
+F:	drivers/i2c/busses/i2c-uniphier*
 F:	drivers/pinctrl/uniphier/
 F:	drivers/tty/serial/8250/8250_uniphier.c
 N:	uniphier
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 08b8617..2a176b0 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -902,6 +902,14 @@ config I2C_TEGRA
 	  If you say yes to this option, support will be included for the
 	  I2C controller embedded in NVIDIA Tegra SOCs
 
+config I2C_UNIPHIER
+	tristate "UniPhier FIFO-less I2C controller"
+	depends on ARCH_UNIPHIER
+	help
+	  If you say yes to this option, support will be included for
+	  the UniPhier FIFO-less I2C interface embedded in PH1-LD4, PH1-sLD8,
+	  or older UniPhier SoCs.
+
 config I2C_VERSATILE
 	tristate "ARM Versatile/Realview I2C bus support"
 	depends on ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 6df3b30..f9f0902 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -87,6 +87,7 @@ obj-$(CONFIG_I2C_ST)		+= i2c-st.o
 obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_SUN6I_P2WI)	+= i2c-sun6i-p2wi.o
 obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
+obj-$(CONFIG_I2C_UNIPHIER)	+= i2c-uniphier.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 obj-$(CONFIG_I2C_WMT)		+= i2c-wmt.o
 obj-$(CONFIG_I2C_OCTEON)	+= i2c-octeon.o
diff --git a/drivers/i2c/busses/i2c-uniphier.c b/drivers/i2c/busses/i2c-uniphier.c
new file mode 100644
index 0000000..e3c3861
--- /dev/null
+++ b/drivers/i2c/busses/i2c-uniphier.c
@@ -0,0 +1,441 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define UNIPHIER_I2C_DTRM	0x00	/* TX register */
+#define     UNIPHIER_I2C_DTRM_IRQEN	BIT(11)	/* enable interrupt */
+#define     UNIPHIER_I2C_DTRM_STA	BIT(10)	/* start condition */
+#define     UNIPHIER_I2C_DTRM_STO	BIT(9)	/* stop condition */
+#define     UNIPHIER_I2C_DTRM_NACK	BIT(8)	/* do not return ACK */
+#define     UNIPHIER_I2C_DTRM_RD	BIT(0)	/* read transaction */
+#define UNIPHIER_I2C_DREC	0x04	/* RX register */
+#define     UNIPHIER_I2C_DREC_MST	BIT(14)	/* 1 = master, 0 = slave */
+#define     UNIPHIER_I2C_DREC_TX	BIT(13)	/* 1 = transmit, 0 = receive */
+#define     UNIPHIER_I2C_DREC_STS	BIT(12)	/* stop condition detected */
+#define     UNIPHIER_I2C_DREC_LRB	BIT(11)	/* no ACK */
+#define     UNIPHIER_I2C_DREC_LAB	BIT(9)	/* arbitration lost */
+#define     UNIPHIER_I2C_DREC_BBN	BIT(8)	/* bus not busy */
+#define UNIPHIER_I2C_MYAD	0x08	/* slave address */
+#define UNIPHIER_I2C_CLK	0x0c	/* clock frequency control */
+#define UNIPHIER_I2C_BRST	0x10	/* bus reset */
+#define     UNIPHIER_I2C_BRST_FOEN	BIT(1)	/* normal operation */
+#define     UNIPHIER_I2C_BRST_RSCL	BIT(0)	/* release SCL */
+#define UNIPHIER_I2C_HOLD	0x14	/* hold time control */
+#define UNIPHIER_I2C_BSTS	0x18	/* bus status monitor */
+#define     UNIPHIER_I2C_BSTS_SDA	BIT(1)	/* readback of SDA line */
+#define     UNIPHIER_I2C_BSTS_SCL	BIT(0)	/* readback of SCL line */
+#define UNIPHIER_I2C_NOISE	0x1c	/* noise filter control */
+#define UNIPHIER_I2C_SETUP	0x20	/* setup time control */
+
+#define UNIPHIER_I2C_DEFAULT_SPEED	100000
+#define UNIPHIER_I2C_MAX_SPEED		400000
+
+struct uniphier_i2c_priv {
+	struct completion comp;
+	struct i2c_adapter adap;
+	void __iomem *membase;
+	struct clk *clk;
+	unsigned int busy_cnt;
+};
+
+static irqreturn_t uniphier_i2c_interrupt(int irq, void *dev_id)
+{
+	struct uniphier_i2c_priv *priv = dev_id;
+
+	/*
+	 * This hardware uses edge triggered interrupt.  Do not touch the
+	 * hardware registers in this handler to make sure to catch the next
+	 * interrupt edge.  Just send a complete signal and return.
+	 */
+	complete(&priv->comp);
+
+	return IRQ_HANDLED;
+}
+
+static int uniphier_i2c_xfer_byte(struct i2c_adapter *adap, u32 txdata,
+				  u32 *rxdatap)
+{
+	struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap);
+	unsigned long time_left;
+	u32 rxdata;
+
+	reinit_completion(&priv->comp);
+
+	txdata |= UNIPHIER_I2C_DTRM_IRQEN;
+	dev_dbg(&adap->dev, "write data: 0x%04x\n", txdata);
+	writel(txdata, priv->membase + UNIPHIER_I2C_DTRM);
+
+	time_left = wait_for_completion_timeout(&priv->comp, adap->timeout);
+	if (unlikely(!time_left)) {
+		dev_err(&adap->dev, "transaction timeout\n");
+		return -ETIMEDOUT;
+	}
+
+	rxdata = readl(priv->membase + UNIPHIER_I2C_DREC);
+	dev_dbg(&adap->dev, "read data: 0x%04x\n", rxdata);
+
+	if (rxdatap)
+		*rxdatap = rxdata;
+
+	return 0;
+}
+
+static int uniphier_i2c_send_byte(struct i2c_adapter *adap, u32 txdata)
+{
+	u32 rxdata;
+	int ret;
+
+	ret = uniphier_i2c_xfer_byte(adap, txdata, &rxdata);
+	if (ret)
+		return ret;
+
+	if (unlikely(rxdata & UNIPHIER_I2C_DREC_LAB)) {
+		dev_dbg(&adap->dev, "arbitration lost\n");
+		return -EAGAIN;
+	}
+	if (unlikely(rxdata & UNIPHIER_I2C_DREC_LRB)) {
+		dev_dbg(&adap->dev, "could not get ACK\n");
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static int uniphier_i2c_tx(struct i2c_adapter *adap, u16 addr, u16 len,
+			   const u8 *buf)
+{
+	int ret;
+
+	dev_dbg(&adap->dev, "start condition\n");
+	ret = uniphier_i2c_send_byte(adap, addr << 1 |
+				     UNIPHIER_I2C_DTRM_STA |
+				     UNIPHIER_I2C_DTRM_NACK);
+	if (ret)
+		return ret;
+
+	while (len--) {
+		ret = uniphier_i2c_send_byte(adap,
+					     UNIPHIER_I2C_DTRM_NACK | *buf++);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int uniphier_i2c_rx(struct i2c_adapter *adap, u16 addr, u16 len,
+			   u8 *buf)
+{
+	int ret;
+
+	dev_dbg(&adap->dev, "start condition\n");
+	ret = uniphier_i2c_send_byte(adap, addr << 1 |
+				     UNIPHIER_I2C_DTRM_STA |
+				     UNIPHIER_I2C_DTRM_NACK |
+				     UNIPHIER_I2C_DTRM_RD);
+	if (ret)
+		return ret;
+
+	while (len--) {
+		u32 rxdata;
+
+		ret = uniphier_i2c_xfer_byte(adap,
+					     len ? 0 : UNIPHIER_I2C_DTRM_NACK,
+					     &rxdata);
+		if (ret)
+			return ret;
+		*buf++ = rxdata;
+	}
+
+	return 0;
+}
+
+static int uniphier_i2c_stop(struct i2c_adapter *adap)
+{
+	dev_dbg(&adap->dev, "stop condition\n");
+	return uniphier_i2c_send_byte(adap, UNIPHIER_I2C_DTRM_STO |
+				      UNIPHIER_I2C_DTRM_NACK);
+}
+
+static int uniphier_i2c_master_xfer_one(struct i2c_adapter *adap,
+					struct i2c_msg *msg, bool stop)
+{
+	bool is_read = msg->flags & I2C_M_RD;
+	bool recovery = false;
+	int ret;
+
+	dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n",
+		is_read ? "receive" : "transmit", msg->addr, msg->len, stop);
+
+	if (is_read)
+		ret = uniphier_i2c_rx(adap, msg->addr, msg->len, msg->buf);
+	else
+		ret = uniphier_i2c_tx(adap, msg->addr, msg->len, msg->buf);
+
+	if (ret == -EAGAIN) /* could not acquire bus. bail out without STOP */
+		return ret;
+
+	if (ret == -ETIMEDOUT) {
+		/* This error is fatal.  Needs recovery. */
+		stop = false;
+		recovery = true;
+	}
+
+	if (stop) {
+		int ret2 = uniphier_i2c_stop(adap);
+
+		if (ret2) {
+			/* Failed to issue STOP.  The bus needs recovery. */
+			recovery = true;
+			ret = ret ?: ret2;
+		}
+	}
+
+	if (recovery)
+		i2c_recover_bus(adap);
+
+	return ret;
+}
+
+static int uniphier_i2c_check_bus_busy(struct i2c_adapter *adap)
+{
+	struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	if (!(readl(priv->membase + UNIPHIER_I2C_DREC) &
+						UNIPHIER_I2C_DREC_BBN)) {
+		if (priv->busy_cnt++ > 3) {
+			/*
+			 * If bus busy continues too long, it is probably
+			 * in a wrong state.  Try bus recovery.
+			 */
+			i2c_recover_bus(adap);
+			priv->busy_cnt = 0;
+		}
+
+		return -EAGAIN;
+	}
+
+	priv->busy_cnt = 0;
+	return 0;
+}
+
+static int uniphier_i2c_master_xfer(struct i2c_adapter *adap,
+				    struct i2c_msg *msgs, int num)
+{
+	struct i2c_msg *msg, *emsg = msgs + num;
+	int ret;
+
+	ret = uniphier_i2c_check_bus_busy(adap);
+	if (ret)
+		return ret;
+
+	for (msg = msgs; msg < emsg; msg++) {
+		/* If next message is read, skip the stop condition */
+		bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD);
+		/* but, force it if I2C_M_STOP is set */
+		if (msg->flags & I2C_M_STOP)
+			stop = true;
+
+		ret = uniphier_i2c_master_xfer_one(adap, msg, stop);
+		if (ret)
+			return ret;
+	}
+
+	return num;
+}
+
+static u32 uniphier_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm uniphier_i2c_algo = {
+	.master_xfer = uniphier_i2c_master_xfer,
+	.functionality = uniphier_i2c_functionality,
+};
+
+static void uniphier_i2c_reset(struct uniphier_i2c_priv *priv, bool reset_on)
+{
+	u32 val = UNIPHIER_I2C_BRST_RSCL;
+
+	val |= reset_on ? 0 : UNIPHIER_I2C_BRST_FOEN;
+	writel(val, priv->membase + UNIPHIER_I2C_BRST);
+}
+
+static int uniphier_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	return !!(readl(priv->membase + UNIPHIER_I2C_BSTS) &
+							UNIPHIER_I2C_BSTS_SCL);
+}
+
+static void uniphier_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	writel(val ? UNIPHIER_I2C_BRST_RSCL : 0,
+	       priv->membase + UNIPHIER_I2C_BRST);
+}
+
+static int uniphier_i2c_get_sda(struct i2c_adapter *adap)
+{
+	struct uniphier_i2c_priv *priv = i2c_get_adapdata(adap);
+
+	return !!(readl(priv->membase + UNIPHIER_I2C_BSTS) &
+							UNIPHIER_I2C_BSTS_SDA);
+}
+
+static void uniphier_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+	uniphier_i2c_reset(i2c_get_adapdata(adap), false);
+}
+
+static struct i2c_bus_recovery_info uniphier_i2c_bus_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.get_scl = uniphier_i2c_get_scl,
+	.set_scl = uniphier_i2c_set_scl,
+	.get_sda = uniphier_i2c_get_sda,
+	.unprepare_recovery = uniphier_i2c_unprepare_recovery,
+};
+
+static int uniphier_i2c_clk_init(struct device *dev,
+				 struct uniphier_i2c_priv *priv)
+{
+	struct device_node *np = dev->of_node;
+	unsigned long clk_rate;
+	u32 bus_speed;
+	int ret;
+
+	if (of_property_read_u32(np, "clock-frequency", &bus_speed))
+		bus_speed = UNIPHIER_I2C_DEFAULT_SPEED;
+
+	if (bus_speed > UNIPHIER_I2C_MAX_SPEED)
+		bus_speed = UNIPHIER_I2C_MAX_SPEED;
+
+	/* Get input clk rate through clk driver */
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "failed to get clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	clk_rate = clk_get_rate(priv->clk);
+
+	uniphier_i2c_reset(priv, true);
+
+	writel((clk_rate / bus_speed / 2 << 16) | (clk_rate / bus_speed),
+	       priv->membase + UNIPHIER_I2C_CLK);
+
+	uniphier_i2c_reset(priv, false);
+
+	return 0;
+}
+
+static int uniphier_i2c_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uniphier_i2c_priv *priv;
+	struct resource *regs;
+	int irq;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->membase = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(priv->membase))
+		return PTR_ERR(priv->membase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to get IRQ number");
+		return irq;
+	}
+
+	init_completion(&priv->comp);
+	priv->adap.owner = THIS_MODULE;
+	priv->adap.algo = &uniphier_i2c_algo;
+	priv->adap.dev.parent = dev;
+	priv->adap.dev.of_node = dev->of_node;
+	strlcpy(priv->adap.name, "UniPhier I2C", sizeof(priv->adap.name));
+	priv->adap.bus_recovery_info = &uniphier_i2c_bus_recovery_info;
+	i2c_set_adapdata(&priv->adap, priv);
+	platform_set_drvdata(pdev, priv);
+
+	ret = uniphier_i2c_clk_init(dev, priv);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(dev, irq, uniphier_i2c_interrupt, 0, pdev->name,
+			       priv);
+	if (ret) {
+		dev_err(dev, "failed to request irq %d\n", irq);
+		goto err;
+	}
+
+	ret = i2c_add_adapter(&priv->adap);
+	if (ret) {
+		dev_err(dev, "failed to add I2C adapter\n");
+		goto err;
+	}
+
+err:
+	if (ret)
+		clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static int uniphier_i2c_remove(struct platform_device *pdev)
+{
+	struct uniphier_i2c_priv *priv = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&priv->adap);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static const struct of_device_id uniphier_i2c_match[] = {
+	{ .compatible = "socionext,uniphier-i2c" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_i2c_match);
+
+static struct platform_driver uniphier_i2c_drv = {
+	.probe  = uniphier_i2c_probe,
+	.remove = uniphier_i2c_remove,
+	.driver = {
+		.name  = "uniphier-i2c",
+		.of_match_table = uniphier_i2c_match,
+	},
+};
+module_platform_driver(uniphier_i2c_drv);
+
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_DESCRIPTION("UniPhier I2C bus driver");
+MODULE_LICENSE("GPL");
-- 
1.9.1

[PATCH v2 2/2] i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver

[Masahiro Yamada]

Add support for on-chip I2C controller used on newer UniPhier SoCs
such as PH1-Pro4, PH1-Pro5, etc.  This adapter is equipped with
8-depth TX/RX FIFOs.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---

Changes in v2:
  - Delete if-block after platform_get_resource()
  - Add I2C_FUNC_SMBUS_EMUL to functionality
  - Add bindings document
  - Fix a typo in a comment block

 .../devicetree/bindings/i2c/i2c-uniphier-f.txt     |  25 +
 drivers/i2c/busses/Kconfig                         |   8 +
 drivers/i2c/busses/Makefile                        |   1 +
 drivers/i2c/busses/i2c-uniphier-f.c                | 584 +++++++++++++++++++++
 4 files changed, 618 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt
 create mode 100644 drivers/i2c/busses/i2c-uniphier-f.c

diff --git a/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt b/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt
new file mode 100644
index 0000000..27fc6f8
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt
@@ -0,0 +1,25 @@
+UniPhier I2C controller (FIFO-builtin)
+
+Required properties:
+- compatible: should be "socionext,uniphier-fi2c".
+- #address-cells: should be 1.
+- #size-cells: should be 0.
+- reg: offset and length of the register set for the device.
+- interrupts: a single interrupt specifier.
+- clocks: phandle to the input clock.
+
+Optional properties:
+- clock-frequency: desired I2C bus frequency in Hz.  The maximum supported
+  value is 400000.  Defaults to 100000 if not specified.
+
+Examples:
+
+	i2c0: i2c@58780000 {
+		compatible = "socionext,uniphier-fi2c";
+		reg = <0x58780000 0x80>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		interrupts = <0 41 4>;
+		clocks = <&i2c_clk>;
+		clock-frequency = <100000>;
+	};
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 2a176b0..0111219 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -910,6 +910,14 @@ config I2C_UNIPHIER
 	  the UniPhier FIFO-less I2C interface embedded in PH1-LD4, PH1-sLD8,
 	  or older UniPhier SoCs.
 
+config I2C_UNIPHIER_F
+	tristate "UniPhier FIFO-builtin I2C controller"
+	depends on ARCH_UNIPHIER
+	help
+	  If you say yes to this option, support will be included for
+	  the UniPhier FIFO-builtin I2C interface embedded in PH1-Pro4,
+	  PH1-Pro5, or newer UniPhier SoCs.
+
 config I2C_VERSATILE
 	tristate "ARM Versatile/Realview I2C bus support"
 	depends on ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index f9f0902..37f2819 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -88,6 +88,7 @@ obj-$(CONFIG_I2C_STU300)	+= i2c-stu300.o
 obj-$(CONFIG_I2C_SUN6I_P2WI)	+= i2c-sun6i-p2wi.o
 obj-$(CONFIG_I2C_TEGRA)		+= i2c-tegra.o
 obj-$(CONFIG_I2C_UNIPHIER)	+= i2c-uniphier.o
+obj-$(CONFIG_I2C_UNIPHIER_F)	+= i2c-uniphier-f.o
 obj-$(CONFIG_I2C_VERSATILE)	+= i2c-versatile.o
 obj-$(CONFIG_I2C_WMT)		+= i2c-wmt.o
 obj-$(CONFIG_I2C_OCTEON)	+= i2c-octeon.o
diff --git a/drivers/i2c/busses/i2c-uniphier-f.c b/drivers/i2c/busses/i2c-uniphier-f.c
new file mode 100644
index 0000000..e8d03bc
--- /dev/null
+++ b/drivers/i2c/busses/i2c-uniphier-f.c
@@ -0,0 +1,584 @@
+/*
+ * Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#define UNIPHIER_FI2C_CR	0x00	/* control register */
+#define     UNIPHIER_FI2C_CR_MST	BIT(3)	/* master mode */
+#define     UNIPHIER_FI2C_CR_STA	BIT(2)	/* start condition */
+#define     UNIPHIER_FI2C_CR_STO	BIT(1)	/* stop condition */
+#define     UNIPHIER_FI2C_CR_NACK	BIT(0)	/* do not return ACK */
+#define UNIPHIER_FI2C_DTTX	0x04	/* TX FIFO */
+#define     UNIPHIER_FI2C_DTTX_CMD	BIT(8)	/* send command (slave addr) */
+#define     UNIPHIER_FI2C_DTTX_RD	BIT(0)	/* read transaction */
+#define UNIPHIER_FI2C_DTRX	0x04	/* RX FIFO */
+#define UNIPHIER_FI2C_SLAD	0x0c	/* slave address */
+#define UNIPHIER_FI2C_CYC	0x10	/* clock cycle control */
+#define UNIPHIER_FI2C_LCTL	0x14	/* clock low period control */
+#define UNIPHIER_FI2C_SSUT	0x18	/* restart/stop setup time control */
+#define UNIPHIER_FI2C_DSUT	0x1c	/* data setup time control */
+#define UNIPHIER_FI2C_INT	0x20	/* interrupt status */
+#define UNIPHIER_FI2C_IE	0x24	/* interrupt enable */
+#define UNIPHIER_FI2C_IC	0x28	/* interrupt clear */
+#define     UNIPHIER_FI2C_INT_TE	BIT(9)	/* TX FIFO empty */
+#define     UNIPHIER_FI2C_INT_RF	BIT(8)	/* RX FIFO full */
+#define     UNIPHIER_FI2C_INT_TC	BIT(7)	/* send complete (STOP) */
+#define     UNIPHIER_FI2C_INT_RC	BIT(6)	/* receive complete (STOP) */
+#define     UNIPHIER_FI2C_INT_TB	BIT(5)	/* sent specified bytes */
+#define     UNIPHIER_FI2C_INT_RB	BIT(4)	/* received specified bytes */
+#define     UNIPHIER_FI2C_INT_NA	BIT(2)	/* no ACK */
+#define     UNIPHIER_FI2C_INT_AL	BIT(1)	/* arbitration lost */
+#define UNIPHIER_FI2C_SR	0x2c	/* status register */
+#define     UNIPHIER_FI2C_SR_DB		BIT(12)	/* device busy */
+#define     UNIPHIER_FI2C_SR_STS	BIT(11)	/* stop condition detected */
+#define     UNIPHIER_FI2C_SR_BB		BIT(8)	/* bus busy */
+#define     UNIPHIER_FI2C_SR_RFF	BIT(3)	/* RX FIFO full */
+#define     UNIPHIER_FI2C_SR_RNE	BIT(2)	/* RX FIFO not empty */
+#define     UNIPHIER_FI2C_SR_TNF	BIT(1)	/* TX FIFO not full */
+#define     UNIPHIER_FI2C_SR_TFE	BIT(0)	/* TX FIFO empty */
+#define UNIPHIER_FI2C_RST	0x34	/* reset control */
+#define     UNIPHIER_FI2C_RST_TBRST	BIT(2)	/* clear TX FIFO */
+#define     UNIPHIER_FI2C_RST_RBRST	BIT(1)	/* clear RX FIFO */
+#define     UNIPHIER_FI2C_RST_RST	BIT(0)	/* forcible bus reset */
+#define UNIPHIER_FI2C_BM	0x38	/* bus monitor */
+#define     UNIPHIER_FI2C_BM_SDAO	BIT(3)	/* output for SDA line */
+#define     UNIPHIER_FI2C_BM_SDAS	BIT(2)	/* readback of SDA line */
+#define     UNIPHIER_FI2C_BM_SCLO	BIT(1)	/* output for SCL line */
+#define     UNIPHIER_FI2C_BM_SCLS	BIT(0)	/* readback of SCL line */
+#define UNIPHIER_FI2C_NOISE	0x3c	/* noise filter control */
+#define UNIPHIER_FI2C_TBC	0x40	/* TX byte count setting */
+#define UNIPHIER_FI2C_RBC	0x44	/* RX byte count setting */
+#define UNIPHIER_FI2C_TBCM	0x48	/* TX byte count monitor */
+#define UNIPHIER_FI2C_RBCM	0x4c	/* RX byte count monitor */
+#define UNIPHIER_FI2C_BRST	0x50	/* bus reset */
+#define     UNIPHIER_FI2C_BRST_FOEN	BIT(1)	/* normal operation */
+#define     UNIPHIER_FI2C_BRST_RSCL	BIT(0)	/* release SCL */
+
+#define UNIPHIER_FI2C_INT_FAULTS	\
+				(UNIPHIER_FI2C_INT_NA | UNIPHIER_FI2C_INT_AL)
+#define UNIPHIER_FI2C_INT_STOP		\
+				(UNIPHIER_FI2C_INT_TC | UNIPHIER_FI2C_INT_RC)
+
+#define UNIPHIER_FI2C_RD		BIT(0)
+#define UNIPHIER_FI2C_STOP		BIT(1)
+#define UNIPHIER_FI2C_MANUAL_NACK	BIT(2)
+#define UNIPHIER_FI2C_BYTE_WISE		BIT(3)
+#define UNIPHIER_FI2C_DEFER_STOP_COMP	BIT(4)
+
+#define UNIPHIER_FI2C_DEFAULT_SPEED	100000
+#define UNIPHIER_FI2C_MAX_SPEED		400000
+#define UNIPHIER_FI2C_FIFO_SIZE		8
+
+struct uniphier_fi2c_priv {
+	struct completion comp;
+	struct i2c_adapter adap;
+	void __iomem *membase;
+	struct clk *clk;
+	unsigned int len;
+	u8 *buf;
+	u32 enabled_irqs;
+	int error;
+	unsigned int flags;
+	unsigned int busy_cnt;
+};
+
+static void uniphier_fi2c_fill_txfifo(struct uniphier_fi2c_priv *priv,
+				      bool first)
+{
+	int fifo_space = UNIPHIER_FI2C_FIFO_SIZE;
+
+	/*
+	 * TX-FIFO stores slave address in it for the first access.
+	 * Decrement the counter.
+	 */
+	if (first)
+		fifo_space--;
+
+	while (priv->len) {
+		if (fifo_space-- <= 0)
+			break;
+
+		dev_dbg(&priv->adap.dev, "write data: %02x\n", *priv->buf);
+		writel(*priv->buf++, priv->membase + UNIPHIER_FI2C_DTTX);
+		priv->len--;
+	}
+}
+
+static void uniphier_fi2c_drain_rxfifo(struct uniphier_fi2c_priv *priv)
+{
+	int fifo_left = priv->flags & UNIPHIER_FI2C_BYTE_WISE ?
+						1 : UNIPHIER_FI2C_FIFO_SIZE;
+
+	while (priv->len) {
+		if (fifo_left-- <= 0)
+			break;
+
+		*priv->buf++ = readl(priv->membase + UNIPHIER_FI2C_DTRX);
+		dev_dbg(&priv->adap.dev, "read data: %02x\n", priv->buf[-1]);
+		priv->len--;
+	}
+}
+
+static void uniphier_fi2c_set_irqs(struct uniphier_fi2c_priv *priv)
+{
+	writel(priv->enabled_irqs, priv->membase + UNIPHIER_FI2C_IE);
+}
+
+static void uniphier_fi2c_clear_irqs(struct uniphier_fi2c_priv *priv)
+{
+	writel(-1, priv->membase + UNIPHIER_FI2C_IC);
+}
+
+static void uniphier_fi2c_stop(struct uniphier_fi2c_priv *priv)
+{
+	dev_dbg(&priv->adap.dev, "stop condition\n");
+
+	priv->enabled_irqs |= UNIPHIER_FI2C_INT_STOP;
+	uniphier_fi2c_set_irqs(priv);
+	writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STO,
+	       priv->membase + UNIPHIER_FI2C_CR);
+}
+
+static irqreturn_t uniphier_fi2c_interrupt(int irq, void *dev_id)
+{
+	struct uniphier_fi2c_priv *priv = dev_id;
+	u32 irq_status;
+
+	irq_status = readl(priv->membase + UNIPHIER_FI2C_INT);
+
+	dev_dbg(&priv->adap.dev,
+		"interrupt: enabled_irqs=%04x, irq_status=%04x\n",
+		priv->enabled_irqs, irq_status);
+
+	if (irq_status & UNIPHIER_FI2C_INT_STOP)
+		goto complete;
+
+	if (unlikely(irq_status & UNIPHIER_FI2C_INT_AL)) {
+		dev_dbg(&priv->adap.dev, "arbitration lost\n");
+		priv->error = -EAGAIN;
+		goto complete;
+	}
+
+	if (unlikely(irq_status & UNIPHIER_FI2C_INT_NA)) {
+		dev_dbg(&priv->adap.dev, "could not get ACK\n");
+		priv->error = -ENXIO;
+		if (priv->flags & UNIPHIER_FI2C_RD) {
+			/*
+			 * work around a hardware bug:
+			 * The receive-completed interrupt is never set even if
+			 * STOP condition is detected after the address phase
+			 * of read transaction fails to get ACK.
+			 * To avoid time-out error, we issue STOP here,
+			 * but do not wait for its completion.
+			 * It should be checked after exiting this handler.
+			 */
+			uniphier_fi2c_stop(priv);
+			priv->flags |= UNIPHIER_FI2C_DEFER_STOP_COMP;
+			goto complete;
+		}
+		goto stop;
+	}
+
+	if (irq_status & UNIPHIER_FI2C_INT_TE) {
+		if (!priv->len)
+			goto data_done;
+
+		uniphier_fi2c_fill_txfifo(priv, false);
+		goto handled;
+	}
+
+	if (irq_status & (UNIPHIER_FI2C_INT_RF | UNIPHIER_FI2C_INT_RB)) {
+		uniphier_fi2c_drain_rxfifo(priv);
+		if (!priv->len)
+			goto data_done;
+
+		if (unlikely(priv->flags & UNIPHIER_FI2C_MANUAL_NACK)) {
+			if (priv->len <= UNIPHIER_FI2C_FIFO_SIZE &&
+			    !(priv->flags & UNIPHIER_FI2C_BYTE_WISE)) {
+				dev_dbg(&priv->adap.dev,
+					"enable read byte count IRQ\n");
+				priv->enabled_irqs |= UNIPHIER_FI2C_INT_RB;
+				uniphier_fi2c_set_irqs(priv);
+				priv->flags |= UNIPHIER_FI2C_BYTE_WISE;
+			}
+			if (priv->len <= 1) {
+				dev_dbg(&priv->adap.dev, "set NACK\n");
+				writel(UNIPHIER_FI2C_CR_MST |
+				       UNIPHIER_FI2C_CR_NACK,
+				       priv->membase + UNIPHIER_FI2C_CR);
+			}
+		}
+
+		goto handled;
+	}
+
+	return IRQ_NONE;
+
+data_done:
+	if (priv->flags & UNIPHIER_FI2C_STOP) {
+stop:
+		uniphier_fi2c_stop(priv);
+	} else {
+complete:
+		priv->enabled_irqs = 0;
+		uniphier_fi2c_set_irqs(priv);
+		complete(&priv->comp);
+	}
+
+handled:
+	uniphier_fi2c_clear_irqs(priv);
+
+	return IRQ_HANDLED;
+}
+
+static void uniphier_fi2c_tx_init(struct uniphier_fi2c_priv *priv, u16 addr)
+{
+	priv->enabled_irqs |= UNIPHIER_FI2C_INT_TE;
+	/* do not use TX byte counter */
+	writel(0, priv->membase + UNIPHIER_FI2C_TBC);
+	/* set slave address */
+	writel(UNIPHIER_FI2C_DTTX_CMD | addr << 1,
+	       priv->membase + UNIPHIER_FI2C_DTTX);
+	/* first chunk of data */
+	uniphier_fi2c_fill_txfifo(priv, true);
+}
+
+static void uniphier_fi2c_rx_init(struct uniphier_fi2c_priv *priv, u16 addr)
+{
+	priv->flags |= UNIPHIER_FI2C_RD;
+
+	if (likely(priv->len < 256)) {
+		/*
+		 * If possible, use RX byte counter.
+		 * It can automatically handle NACK for the last byte.
+		 */
+		writel(priv->len, priv->membase + UNIPHIER_FI2C_RBC);
+		priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF |
+				      UNIPHIER_FI2C_INT_RB;
+	} else {
+		/*
+		 * The byte counter can not count over 256.  In this case,
+		 * do not use it at all.  Drain data when FIFO gets full,
+		 * but treat the last portion as a special case.
+		 */
+		writel(0, priv->membase + UNIPHIER_FI2C_RBC);
+		priv->flags |= UNIPHIER_FI2C_MANUAL_NACK;
+		priv->enabled_irqs |= UNIPHIER_FI2C_INT_RF;
+	}
+
+	/* set slave address with RD bit */
+	writel(UNIPHIER_FI2C_DTTX_CMD | UNIPHIER_FI2C_DTTX_RD | addr << 1,
+	       priv->membase + UNIPHIER_FI2C_DTTX);
+}
+
+static void uniphier_fi2c_reset(struct uniphier_fi2c_priv *priv)
+{
+	writel(UNIPHIER_FI2C_RST_RST, priv->membase + UNIPHIER_FI2C_RST);
+}
+
+static void uniphier_fi2c_prepare_operation(struct uniphier_fi2c_priv *priv)
+{
+	writel(UNIPHIER_FI2C_BRST_FOEN | UNIPHIER_FI2C_BRST_RSCL,
+	       priv->membase + UNIPHIER_FI2C_BRST);
+}
+
+static void uniphier_fi2c_recover(struct uniphier_fi2c_priv *priv)
+{
+	uniphier_fi2c_reset(priv);
+	i2c_recover_bus(&priv->adap);
+}
+
+static int uniphier_fi2c_master_xfer_one(struct i2c_adapter *adap,
+					 struct i2c_msg *msg, bool stop)
+{
+	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+	bool is_read = msg->flags & I2C_M_RD;
+	unsigned long time_left;
+
+	dev_dbg(&adap->dev, "%s: addr=0x%02x, len=%d, stop=%d\n",
+		is_read ? "receive" : "transmit", msg->addr, msg->len, stop);
+
+	priv->len = msg->len;
+	priv->buf = msg->buf;
+	priv->enabled_irqs = UNIPHIER_FI2C_INT_FAULTS;
+	priv->error = 0;
+	priv->flags = 0;
+
+	if (stop)
+		priv->flags |= UNIPHIER_FI2C_STOP;
+
+	reinit_completion(&priv->comp);
+	uniphier_fi2c_clear_irqs(priv);
+	writel(UNIPHIER_FI2C_RST_TBRST | UNIPHIER_FI2C_RST_RBRST,
+	       priv->membase + UNIPHIER_FI2C_RST);	/* reset TX/RX FIFO */
+
+	if (is_read)
+		uniphier_fi2c_rx_init(priv, msg->addr);
+	else
+		uniphier_fi2c_tx_init(priv, msg->addr);
+
+	uniphier_fi2c_set_irqs(priv);
+
+	dev_dbg(&adap->dev, "start condition\n");
+	writel(UNIPHIER_FI2C_CR_MST | UNIPHIER_FI2C_CR_STA,
+	       priv->membase + UNIPHIER_FI2C_CR);
+
+	time_left = wait_for_completion_timeout(&priv->comp, adap->timeout);
+	if (!time_left) {
+		dev_err(&adap->dev, "transaction timeout.\n");
+		uniphier_fi2c_recover(priv);
+		return -ETIMEDOUT;
+	}
+	dev_dbg(&adap->dev, "complete\n");
+
+	if (unlikely(priv->flags & UNIPHIER_FI2C_DEFER_STOP_COMP)) {
+		u32 status = readl(priv->membase + UNIPHIER_FI2C_SR);
+
+		if (!(status & UNIPHIER_FI2C_SR_STS) ||
+		    status & UNIPHIER_FI2C_SR_BB) {
+			dev_err(&adap->dev,
+				"stop condition was not completed.\n");
+			uniphier_fi2c_recover(priv);
+			return -EBUSY;
+		}
+	}
+
+	return priv->error;
+}
+
+static int uniphier_fi2c_check_bus_busy(struct i2c_adapter *adap)
+{
+	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+	if (readl(priv->membase + UNIPHIER_FI2C_SR) & UNIPHIER_FI2C_SR_DB) {
+		if (priv->busy_cnt++ > 3) {
+			/*
+			 * If bus busy continues too long, it is probably
+			 * in a wrong state.  Try bus recovery.
+			 */
+			uniphier_fi2c_recover(priv);
+			priv->busy_cnt = 0;
+		}
+
+		return -EAGAIN;
+	}
+
+	priv->busy_cnt = 0;
+	return 0;
+}
+
+static int uniphier_fi2c_master_xfer(struct i2c_adapter *adap,
+				     struct i2c_msg *msgs, int num)
+{
+	struct i2c_msg *msg, *emsg = msgs + num;
+	int ret;
+
+	ret = uniphier_fi2c_check_bus_busy(adap);
+	if (ret)
+		return ret;
+
+	for (msg = msgs; msg < emsg; msg++) {
+		/* If next message is read, skip the stop condition */
+		bool stop = !(msg + 1 < emsg && msg[1].flags & I2C_M_RD);
+		/* but, force it if I2C_M_STOP is set */
+		if (msg->flags & I2C_M_STOP)
+			stop = true;
+
+		ret = uniphier_fi2c_master_xfer_one(adap, msg, stop);
+		if (ret)
+			return ret;
+	}
+
+	return num;
+}
+
+static u32 uniphier_fi2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm uniphier_fi2c_algo = {
+	.master_xfer = uniphier_fi2c_master_xfer,
+	.functionality = uniphier_fi2c_functionality,
+};
+
+static int uniphier_fi2c_get_scl(struct i2c_adapter *adap)
+{
+	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+	return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
+							UNIPHIER_FI2C_BM_SCLS);
+}
+
+static void uniphier_fi2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+	writel(val ? UNIPHIER_FI2C_BRST_RSCL : 0,
+	       priv->membase + UNIPHIER_FI2C_BRST);
+}
+
+static int uniphier_fi2c_get_sda(struct i2c_adapter *adap)
+{
+	struct uniphier_fi2c_priv *priv = i2c_get_adapdata(adap);
+
+	return !!(readl(priv->membase + UNIPHIER_FI2C_BM) &
+							UNIPHIER_FI2C_BM_SDAS);
+}
+
+static void uniphier_fi2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+	uniphier_fi2c_prepare_operation(i2c_get_adapdata(adap));
+}
+
+static struct i2c_bus_recovery_info uniphier_fi2c_bus_recovery_info = {
+	.recover_bus = i2c_generic_scl_recovery,
+	.get_scl = uniphier_fi2c_get_scl,
+	.set_scl = uniphier_fi2c_set_scl,
+	.get_sda = uniphier_fi2c_get_sda,
+	.unprepare_recovery = uniphier_fi2c_unprepare_recovery,
+};
+
+static int uniphier_fi2c_clk_init(struct device *dev,
+				  struct uniphier_fi2c_priv *priv)
+{
+	struct device_node *np = dev->of_node;
+	unsigned long clk_rate;
+	u32 bus_speed, clk_count;
+	int ret;
+
+	if (of_property_read_u32(np, "clock-frequency", &bus_speed))
+		bus_speed = UNIPHIER_FI2C_DEFAULT_SPEED;
+
+	if (bus_speed > UNIPHIER_FI2C_MAX_SPEED)
+		bus_speed = UNIPHIER_FI2C_MAX_SPEED;
+
+	/* Get input clk rate through clk driver */
+	priv->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(dev, "failed to get clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		return ret;
+
+	clk_rate = clk_get_rate(priv->clk);
+
+	uniphier_fi2c_reset(priv);
+
+	clk_count = clk_rate / bus_speed;
+
+	writel(clk_count, priv->membase + UNIPHIER_FI2C_CYC);
+	writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_LCTL);
+	writel(clk_count / 2, priv->membase + UNIPHIER_FI2C_SSUT);
+	writel(clk_count / 16, priv->membase + UNIPHIER_FI2C_DSUT);
+
+	uniphier_fi2c_prepare_operation(priv);
+
+	return 0;
+}
+
+static int uniphier_fi2c_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uniphier_fi2c_priv *priv;
+	struct resource *regs;
+	int irq;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->membase = devm_ioremap_resource(dev, regs);
+	if (IS_ERR(priv->membase))
+		return PTR_ERR(priv->membase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to get IRQ number");
+		return irq;
+	}
+
+	init_completion(&priv->comp);
+	priv->adap.owner = THIS_MODULE;
+	priv->adap.algo = &uniphier_fi2c_algo;
+	priv->adap.dev.parent = dev;
+	priv->adap.dev.of_node = dev->of_node;
+	strlcpy(priv->adap.name, "UniPhier FI2C", sizeof(priv->adap.name));
+	priv->adap.bus_recovery_info = &uniphier_fi2c_bus_recovery_info;
+	i2c_set_adapdata(&priv->adap, priv);
+	platform_set_drvdata(pdev, priv);
+
+	ret = uniphier_fi2c_clk_init(dev, priv);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(dev, irq, uniphier_fi2c_interrupt, 0,
+			       pdev->name, priv);
+	if (ret) {
+		dev_err(dev, "failed to request irq %d\n", irq);
+		goto err;
+	}
+
+	ret = i2c_add_adapter(&priv->adap);
+	if (ret) {
+		dev_err(dev, "failed to add I2C adapter\n");
+		goto err;
+	}
+
+err:
+	if (ret)
+		clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static int uniphier_fi2c_remove(struct platform_device *pdev)
+{
+	struct uniphier_fi2c_priv *priv = platform_get_drvdata(pdev);
+
+	i2c_del_adapter(&priv->adap);
+	clk_disable_unprepare(priv->clk);
+
+	return 0;
+}
+
+static const struct of_device_id uniphier_fi2c_match[] = {
+	{ .compatible = "socionext,uniphier-fi2c" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_fi2c_match);
+
+static struct platform_driver uniphier_fi2c_drv = {
+	.probe  = uniphier_fi2c_probe,
+	.remove = uniphier_fi2c_remove,
+	.driver = {
+		.name  = "uniphier-fi2c",
+		.of_match_table = uniphier_fi2c_match,
+	},
+};
+module_platform_driver(uniphier_fi2c_drv);
+
+MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
+MODULE_DESCRIPTION("UniPhier FIFO-builtin I2C bus driver");
+MODULE_LICENSE("GPL");
-- 
1.9.1

Re: [PATCH v2 1/2] i2c: uniphier: add UniPhier FIFO-less I2C driver

[Wolfram Sang]

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On Fri, Oct 23, 2015 at 07:51:59PM +0900, Masahiro Yamada wrote:
> Add support for on-chip I2C controller used on old UniPhier SoCs
> such as PH1-LD4, PH1-sLD8, etc.  This adapter is so simple that
> it has no FIFO in it.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro-uWyLwvC0a2jby3iVrkZq2A@public.gmane.org>

Applied to for-next, thanks!


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Re: [PATCH v2 2/2] i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver

[Wolfram Sang]

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On Fri, Oct 23, 2015 at 07:52:00PM +0900, Masahiro Yamada wrote:
> Add support for on-chip I2C controller used on newer UniPhier SoCs
> such as PH1-Pro4, PH1-Pro5, etc.  This adapter is equipped with
> 8-depth TX/RX FIFOs.
> 
> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Applied to for-next, thanks!


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Re: [PATCH v2 0/2] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform

[Lee Jones]

> This series adds two I2C controller drivers.
> (they are completely different IPs.)
> 
> The first one is a very simple FIFO-less I2C controller,
> which is used on some older UniPhier SoCs.
> 
> The other one is higher-performance I2C controller with TX/RX FIFO,
> used on newer UniPhier SoCs.

And you have sent this to me because ... ?

> Changes in v2:
>   - Delete if-block after platform_get_resource()
>   - Add I2C_FUNC_SMBUS_EMUL to functionality
>   - Add bindings document
>   - Add entry to MAINTAINERS
>   - Delete if-block after platform_get_resource()
>   - Add I2C_FUNC_SMBUS_EMUL to functionality
>   - Add bindings document
>   - Fix a typo in a comment block
> 
> Masahiro Yamada (2):
>   i2c: uniphier: add UniPhier FIFO-less I2C driver
>   i2c: uniphier_f: add UniPhier FIFO-builtin I2C driver
> 
>  .../devicetree/bindings/i2c/i2c-uniphier-f.txt     |  25 +
>  .../devicetree/bindings/i2c/i2c-uniphier.txt       |  25 +
>  MAINTAINERS                                        |   1 +
>  drivers/i2c/busses/Kconfig                         |  16 +
>  drivers/i2c/busses/Makefile                        |   2 +
>  drivers/i2c/busses/i2c-uniphier-f.c                | 584 +++++++++++++++++++++
>  drivers/i2c/busses/i2c-uniphier.c                  | 441 ++++++++++++++++
>  7 files changed, 1094 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier-f.txt
>  create mode 100644 Documentation/devicetree/bindings/i2c/i2c-uniphier.txt
>  create mode 100644 drivers/i2c/busses/i2c-uniphier-f.c
>  create mode 100644 drivers/i2c/busses/i2c-uniphier.c
> 

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

Re: [PATCH v2 0/2] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform

[Masahiro Yamada]

Hi Lee,


2015-10-26 17:17 GMT+09:00 Lee Jones <lee.jones@linaro.org>:
>> This series adds two I2C controller drivers.
>> (they are completely different IPs.)
>>
>> The first one is a very simple FIFO-less I2C controller,
>> which is used on some older UniPhier SoCs.
>>
>> The other one is higher-performance I2C controller with TX/RX FIFO,
>> used on newer UniPhier SoCs.
>
> And you have sent this to me because ... ?


No special reason.


I sent this series to linux-i2c@vger.kernel.org.

I guess you were automatically CC'ed by scripts/get_maintainer.pl.

Using get_maintainer.pl is a normal process when sending patches, I think.





-- 
Best Regards
Masahiro Yamada

Re: [PATCH v2 0/2] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform

[Geert Uytterhoeven]

On Mon, Oct 26, 2015 at 9:27 AM, Masahiro Yamada
<yamada.masahiro-uWyLwvC0a2jby3iVrkZq2A@public.gmane.org> wrote:
> 2015-10-26 17:17 GMT+09:00 Lee Jones <lee.jones-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>:
>>> This series adds two I2C controller drivers.
>>> (they are completely different IPs.)
>>>
>>> The first one is a very simple FIFO-less I2C controller,
>>> which is used on some older UniPhier SoCs.
>>>
>>> The other one is higher-performance I2C controller with TX/RX FIFO,
>>> used on newer UniPhier SoCs.
>>
>> And you have sent this to me because ... ?
>
>
> No special reason.
>
>
> I sent this series to linux-i2c-u79uwXL29TaiAVqoAR/hOA@public.gmane.org
>
> I guess you were automatically CC'ed by scripts/get_maintainer.pl.
>
> Using get_maintainer.pl is a normal process when sending patches, I think.

Please use common sense. It doesn't make much sense to CC everybody who
ever made a minor edit to an affected file.

If checkpatch comes up with more than 5 names, this should ring a bell.

Thanks!

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert-Td1EMuHUCqxL1ZNQvxDV9g@public.gmane.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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Re: [PATCH v2 0/2] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform

[Wolfram Sang]

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On Mon, Oct 26, 2015 at 09:31:15AM +0100, Geert Uytterhoeven wrote:
> On Mon, Oct 26, 2015 at 9:27 AM, Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
> > 2015-10-26 17:17 GMT+09:00 Lee Jones <lee.jones@linaro.org>:
> >>> This series adds two I2C controller drivers.
> >>> (they are completely different IPs.)
> >>>
> >>> The first one is a very simple FIFO-less I2C controller,
> >>> which is used on some older UniPhier SoCs.
> >>>
> >>> The other one is higher-performance I2C controller with TX/RX FIFO,
> >>> used on newer UniPhier SoCs.
> >>
> >> And you have sent this to me because ... ?
> >
> >
> > No special reason.
> >
> >
> > I sent this series to linux-i2c@vger.kernel.org.
> >
> > I guess you were automatically CC'ed by scripts/get_maintainer.pl.
> >
> > Using get_maintainer.pl is a normal process when sending patches, I think.
> 
> Please use common sense. It doesn't make much sense to CC everybody who
> ever made a minor edit to an affected file.
> 
> If checkpatch comes up with more than 5 names, this should ring a bell.

I usually use get_maintainer.pl with --no-git-fallback to catch people
listed in MAINTAINERS only. But mileages vary a lot in that area.


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Re: [PATCH v2 0/2] i2c: uniphier: add two I2C controller drivers for UniPhier SoC platform

[Lee Jones]

On Mon, 26 Oct 2015, Geert Uytterhoeven wrote:
> On Mon, Oct 26, 2015 at 9:27 AM, Masahiro Yamada
> <yamada.masahiro@socionext.com> wrote:
> > 2015-10-26 17:17 GMT+09:00 Lee Jones <lee.jones@linaro.org>:
> >>> This series adds two I2C controller drivers.
> >>> (they are completely different IPs.)
> >>>
> >>> The first one is a very simple FIFO-less I2C controller,
> >>> which is used on some older UniPhier SoCs.
> >>>
> >>> The other one is higher-performance I2C controller with TX/RX FIFO,
> >>> used on newer UniPhier SoCs.
> >>
> >> And you have sent this to me because ... ?
> >
> >
> > No special reason.
> >
> >
> > I sent this series to linux-i2c@vger.kernel.org.
> >
> > I guess you were automatically CC'ed by scripts/get_maintainer.pl.
> >
> > Using get_maintainer.pl is a normal process when sending patches, I think.
> 
> Please use common sense. It doesn't make much sense to CC everybody who
> ever made a minor edit to an affected file.
> 
> If checkpatch comes up with more than 5 names, this should ring a bell.

+1

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog