Merge branch 'for-next/gpio'

5 files changed, 300 insertions, 10 deletions

diff --git a/drivers/eeprom/at24.c b/drivers/eeprom/at24.c
index bb2dd533b6..76f30e7e22 100644
--- a/drivers/eeprom/at24.c
+++ b/drivers/eeprom/at24.c
@@ -21,6 +21,8 @@
 #include <linux/log2.h>
 #include <i2c/i2c.h>
 #include <i2c/at24.h>
+#include <gpio.h>
+#include <of_gpio.h>
 
 /*
  * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable.
@@ -55,6 +57,8 @@ struct at24_data {
 	u8 *writebuf;
 	unsigned write_max;
 	unsigned num_addresses;
+	int wp_gpio;
+	int wp_active_low;
 
 	/*
 	 * Some chips tie up multiple I2C addresses; dummy devices reserve
@@ -345,6 +349,25 @@ static ssize_t at24_cdev_write(struct cdev *cdev, const void *buf, size_t count,
 	return at24_write(at24, buf, off, count);
 }
 
+static ssize_t at24_cdev_protect(struct cdev *cdev, size_t count, loff_t offset,
+		int prot)
+{
+	struct at24_data *at24 = cdev->priv;
+
+	if (!gpio_is_valid(at24->wp_gpio))
+		return -EOPNOTSUPP;
+
+	prot = !!prot;
+	if (at24->wp_active_low)
+		prot = !prot;
+
+	gpio_set_value(at24->wp_gpio, prot);
+
+	udelay(50);
+
+	return 0;
+}
+
 static int at24_probe(struct device_d *dev)
 {
 	struct i2c_client *client = to_i2c_client(dev);
@@ -403,6 +426,7 @@ static int at24_probe(struct device_d *dev)
 	at24->cdev.ops = &at24->fops;
 	at24->fops.lseek = dev_lseek_default;
 	at24->fops.read	= at24_cdev_read,
+	at24->fops.protect = at24_cdev_protect,
 	at24->cdev.size = chip.byte_len;
 
 	writable = !(chip.flags & AT24_FLAG_READONLY);
@@ -419,6 +443,19 @@ static int at24_probe(struct device_d *dev)
 		at24->writebuf = xmalloc(write_max + 2);
 	}
 
+	at24->wp_gpio = -1;
+	if (dev->device_node) {
+		enum of_gpio_flags flags;
+		at24->wp_gpio = of_get_named_gpio_flags(dev->device_node,
+				"wp-gpios", 0, &flags);
+		if (gpio_is_valid(at24->wp_gpio)) {
+			at24->wp_active_low = flags & OF_GPIO_ACTIVE_LOW;
+			gpio_request(at24->wp_gpio, "eeprom-wp");
+			gpio_direction_output(at24->wp_gpio,
+					!at24->wp_active_low);
+		}
+	}
+
 	at24->client[0] = client;
 
 	/* use dummy devices for multiple-address chips */
@@ -440,6 +477,7 @@ static int at24_probe(struct device_d *dev)
 	return 0;
 
 err_clients:
+	gpio_free(at24->wp_gpio);
 	kfree(at24->writebuf);
 	kfree(at24);
 err_out:
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index dc43eb83a4..2563c0d25a 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -106,9 +106,10 @@ static int sclhi(struct i2c_algo_bit_data *adap)
 		}
 	}
 #ifdef DEBUG
-	if (jiffies != start && i2c_debug >= 3)
-		pr_debug("i2c-algo-bit: needed %ld jiffies for SCL to go "
-			 "high\n", jiffies - start);
+	if ((get_time_ns() - start) < 10000)
+		pr_debug("i2c-algo-bit: needed %u usecs for SCL to go "
+			 "high\n", (unsigned int)(get_time_ns() - start) /
+			 1000);
 #endif
 
 done:
@@ -116,6 +117,31 @@ done:
 	return 0;
 }
 
+static int wait_busy(struct i2c_algo_bit_data *adap)
+{
+	uint64_t start;
+
+	if (sclhi(adap) < 0)
+		return -ETIMEDOUT;
+
+	start = get_time_ns();
+	while (!getsda(adap)) {
+		if (is_timeout(start, adap->timeout_ms * MSECOND)) {
+			if (getsda(adap))
+				break;
+			return -ETIMEDOUT;
+		}
+	}
+#ifdef DEBUG
+	if ((get_time_ns() - start) < 10000)
+		pr_debug("i2c-algo-bit: needed %u usecs for SDA to go "
+			 "high\n", (unsigned int)(get_time_ns() - start) /
+			 1000);
+#endif
+
+	udelay(adap->udelay);
+	return 0;
+}
 
 /* --- other auxiliary functions --------------------------------------	*/
 static void i2c_start(struct i2c_algo_bit_data *adap)
@@ -426,10 +452,7 @@ static int readbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
 		count--;
 
 		bit_dbg(2, &i2c_adap->dev, "readbytes: 0x%02x %s\n",
-			inval,
-			(flags & I2C_M_NO_RD_ACK)
-				? "(no ack/nak)"
-				: (count ? "A" : "NA"));
+			inval, count ? "A" : "NA");
 
 		inval = acknak(i2c_adap, count);
 		if (inval < 0)
@@ -514,6 +537,13 @@ static int bit_xfer(struct i2c_adapter *i2c_adap,
 			return ret;
 	}
 
+	if (wait_busy(adap) < 0) { /* timeout */
+		dev_warn(&i2c_adap->dev, "timeout waiting for bus ready\n");
+		ret = i2c_recover_bus(i2c_adap);
+		if (ret < 0)
+			return ret;
+	}
+
 	bit_dbg(3, &i2c_adap->dev, "emitting start condition\n");
 	i2c_start(adap);
 	for (i = 0; i < num; i++) {
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index b4a0ecdb20..9362ed181f 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -10,6 +10,7 @@
 
 #include <common.h>
 #include <driver.h>
+#include <malloc.h>
 #include <i2c/i2c.h>
 #include <i2c/i2c-algo-bit.h>
 #include <i2c/i2c-gpio.h>
@@ -187,6 +188,13 @@ static int i2c_gpio_probe(struct device_d *dev)
 	adap->algo_data = bit_data;
 	adap->dev.parent = dev;
 	adap->dev.device_node = dev->device_node;
+	adap->bus_recovery_info = xzalloc(sizeof(*adap->bus_recovery_info));
+	adap->bus_recovery_info->scl_gpio = pdata->scl_pin;
+	adap->bus_recovery_info->sda_gpio = pdata->sda_pin;
+	adap->bus_recovery_info->get_sda = i2c_get_sda_gpio_value;
+	adap->bus_recovery_info->get_scl = i2c_get_scl_gpio_value;
+	adap->bus_recovery_info->set_scl = i2c_set_scl_gpio_value;
+	adap->bus_recovery_info->recover_bus = i2c_generic_scl_recovery;
 
 	adap->nr = dev->id;
 	ret = i2c_bit_add_numbered_bus(adap);
@@ -201,10 +209,12 @@ static int i2c_gpio_probe(struct device_d *dev)
 	return 0;
 
 err_add_bus:
+	free(adap->bus_recovery_info);
 	gpio_free(pdata->scl_pin);
 err_request_scl:
 	gpio_free(pdata->sda_pin);
 err_request_sda:
+	free(priv);
 	return ret;
 }
 
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 330db98982..48c55daeda 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -107,16 +107,20 @@
 #define OMAP_I2C_SCLH_HSSCLH	8
 
 /* I2C System Test Register (OMAP_I2C_SYSTEST): */
-#ifdef DEBUG
 #define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
 #define OMAP_I2C_SYSTEST_FREE		(1 << 14)	/* Free running mode */
 #define OMAP_I2C_SYSTEST_TMODE_MASK	(3 << 12)	/* Test mode select */
 #define OMAP_I2C_SYSTEST_TMODE_SHIFT	(12)		/* Test mode select */
+/* Functional mode */
+#define OMAP_I2C_SYSTEST_SCL_I_FUNC	(1 << 8)	/* SCL line input value */
+#define OMAP_I2C_SYSTEST_SCL_O_FUNC	(1 << 7)	/* SCL line output value */
+#define OMAP_I2C_SYSTEST_SDA_I_FUNC	(1 << 6)	/* SDA line input value */
+#define OMAP_I2C_SYSTEST_SDA_O_FUNC	(1 << 5)	/* SDA line output value */
+/* SDA/SCL IO mode */
 #define OMAP_I2C_SYSTEST_SCL_I		(1 << 3)	/* SCL line sense in */
 #define OMAP_I2C_SYSTEST_SCL_O		(1 << 2)	/* SCL line drive out */
 #define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
 #define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
-#endif
 
 /* OCP_SYSSTATUS bit definitions */
 #define SYSS_RESETDONE_MASK		(1 << 0)
@@ -492,7 +496,7 @@ static int omap_i2c_wait_for_bb(struct i2c_adapter *adapter)
 	while (omap_i2c_read_reg(i2c_omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
 		if (is_timeout(start, MSECOND)) {
 			dev_warn(&adapter->dev, "timeout waiting for bus ready\n");
-			return -ETIMEDOUT;
+			return i2c_recover_bus(adapter);
 		}
 	}
 
@@ -673,6 +677,10 @@ omap_i2c_isr(struct omap_i2c_struct *dev)
 		/*
 		 * ProDB0017052: Clear ARDY bit twice
 		 */
+		if (stat & OMAP_I2C_STAT_ARDY)
+			omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ARDY);
+
+
 		if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
 					OMAP_I2C_STAT_AL)) {
 			omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
@@ -986,6 +994,79 @@ out:
 #define OMAP_I2C_SCHEME_0		0
 #define OMAP_I2C_SCHEME_1		1
 
+static int omap_i2c_get_scl(struct i2c_adapter *adapter)
+{
+	struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(i2c_omap, OMAP_I2C_SYSTEST_REG);
+
+	return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;
+}
+
+static int omap_i2c_get_sda(struct i2c_adapter *adapter)
+{
+	struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(i2c_omap, OMAP_I2C_SYSTEST_REG);
+
+	return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;
+}
+
+static void omap_i2c_set_scl(struct i2c_adapter *adapter, int val)
+{
+	struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(i2c_omap, OMAP_I2C_SYSTEST_REG);
+	if (val)
+		reg |= OMAP_I2C_SYSTEST_SCL_O;
+	else
+		reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+	omap_i2c_write_reg(i2c_omap, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_prepare_recovery(struct i2c_adapter *adapter)
+{
+	struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(i2c_omap, OMAP_I2C_SYSTEST_REG);
+	/* enable test mode */
+	reg |= OMAP_I2C_SYSTEST_ST_EN;
+	/* select SDA/SCL IO mode */
+	reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT;
+	/* set SCL to high-impedance state (reset value is 0) */
+	reg |= OMAP_I2C_SYSTEST_SCL_O;
+	/* set SDA to high-impedance state (reset value is 0) */
+	reg |= OMAP_I2C_SYSTEST_SDA_O;
+	omap_i2c_write_reg(i2c_omap, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_unprepare_recovery(struct i2c_adapter *adapter)
+{
+	struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(i2c_omap, OMAP_I2C_SYSTEST_REG);
+	/* restore reset values */
+	reg &= ~OMAP_I2C_SYSTEST_ST_EN;
+	reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK;
+	reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+	reg &= ~OMAP_I2C_SYSTEST_SDA_O;
+	omap_i2c_write_reg(i2c_omap, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {
+	.get_scl		= omap_i2c_get_scl,
+	.get_sda		= omap_i2c_get_sda,
+	.set_scl		= omap_i2c_set_scl,
+	.prepare_recovery	= omap_i2c_prepare_recovery,
+	.unprepare_recovery	= omap_i2c_unprepare_recovery,
+	.recover_bus		= i2c_generic_scl_recovery,
+};
+
 static int __init
 i2c_omap_probe(struct device_d *pdev)
 {
@@ -1097,6 +1178,7 @@ i2c_omap_probe(struct device_d *pdev)
 	i2c_omap->adapter.nr = pdev->id;
 	i2c_omap->adapter.dev.parent = pdev;
 	i2c_omap->adapter.dev.device_node = pdev->device_node;
+	i2c_omap->adapter.bus_recovery_info = &omap_i2c_bus_recovery_info;
 
 	/* i2c device drivers may be active on return from add_adapter() */
 	r = i2c_add_numbered_adapter(&i2c_omap->adapter);
diff --git a/drivers/i2c/i2c.c b/drivers/i2c/i2c.c
index f0df666b97..52aaea8170 100644
--- a/drivers/i2c/i2c.c
+++ b/drivers/i2c/i2c.c
@@ -23,6 +23,7 @@
 #include <xfuncs.h>
 #include <init.h>
 #include <of.h>
+#include <gpio.h>
 
 #include <i2c/i2c.h>
 
@@ -228,6 +229,135 @@ int i2c_write_reg(struct i2c_client *client, u32 addr, const u8 *buf, u16 count)
 }
 EXPORT_SYMBOL(i2c_write_reg);
 
+/* i2c bus recovery routines */
+int i2c_get_scl_gpio_value(struct i2c_adapter *adap)
+{
+	gpio_direction_input(adap->bus_recovery_info->scl_gpio);
+	return gpio_get_value(adap->bus_recovery_info->scl_gpio);
+}
+
+void i2c_set_scl_gpio_value(struct i2c_adapter *adap, int val)
+{
+	if (val)
+		gpio_direction_input(adap->bus_recovery_info->scl_gpio);
+	else
+		gpio_direction_output(adap->bus_recovery_info->scl_gpio, 0);
+}
+
+int i2c_get_sda_gpio_value(struct i2c_adapter *adap)
+{
+	return gpio_get_value(adap->bus_recovery_info->sda_gpio);
+}
+
+static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+	struct device_d *dev = &adap->dev;
+	int ret = 0;
+
+	ret = gpio_request_one(bri->scl_gpio, GPIOF_IN, "i2c-scl");
+	if (ret) {
+		dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio);
+		return ret;
+	}
+
+	if (bri->get_sda) {
+		if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) {
+			/* work without SDA polling */
+			dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n",
+					bri->sda_gpio);
+			bri->get_sda = NULL;
+		}
+	}
+
+	return ret;
+}
+
+static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+
+	if (bri->get_sda)
+		gpio_free(bri->sda_gpio);
+
+	gpio_free(bri->scl_gpio);
+}
+
+/*
+ * We are generating clock pulses. ndelay() determines durating of clk pulses.
+ * We will generate clock with rate 100 KHz and so duration of both clock levels
+ * is: delay in ns = (10^6 / 100) / 2
+ */
+#define RECOVERY_NDELAY		5000
+#define RECOVERY_CLK_CNT	9
+
+static int i2c_generic_recovery(struct i2c_adapter *adap)
+{
+	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
+	int i = 0, val = 1, ret = 0;
+
+	if (bri->prepare_recovery)
+		bri->prepare_recovery(adap);
+
+	bri->set_scl(adap, val);
+	ndelay(RECOVERY_NDELAY);
+
+	/*
+	 * By this time SCL is high, as we need to give 9 falling-rising edges
+	 */
+	while (i++ < RECOVERY_CLK_CNT * 2) {
+		if (val) {
+			/* Break if SDA is high */
+			if (bri->get_sda && bri->get_sda(adap))
+					break;
+			/* SCL shouldn't be low here */
+			if (!bri->get_scl(adap)) {
+				dev_err(&adap->dev,
+					"SCL is stuck low, exit recovery\n");
+				ret = -EBUSY;
+				break;
+			}
+		}
+
+		val = !val;
+		bri->set_scl(adap, val);
+		ndelay(RECOVERY_NDELAY);
+	}
+
+	if (bri->unprepare_recovery)
+		bri->unprepare_recovery(adap);
+
+	return ret;
+}
+
+int i2c_generic_scl_recovery(struct i2c_adapter *adap)
+{
+	return i2c_generic_recovery(adap);
+}
+
+int i2c_generic_gpio_recovery(struct i2c_adapter *adap)
+{
+	int ret;
+
+	ret = i2c_get_gpios_for_recovery(adap);
+	if (ret)
+		return ret;
+
+	ret = i2c_generic_recovery(adap);
+	i2c_put_gpios_for_recovery(adap);
+
+	return ret;
+}
+
+int i2c_recover_bus(struct i2c_adapter *adap)
+{
+	if (!adap->bus_recovery_info)
+		return -EOPNOTSUPP;
+
+	dev_dbg(&adap->dev, "Trying i2c bus recovery\n");
+	return adap->bus_recovery_info->recover_bus(adap);
+}
+
 /**
  * i2c_new_device - instantiate one new I2C device
  *