1 files changed, 103 insertions, 53 deletions

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index a636ea0eb50a..968a8b8794da 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -32,6 +32,7 @@
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/i2c-pxa.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 
 /* I2C register field definitions */
@@ -217,7 +218,7 @@ static const struct platform_device_id i2c_pxa_id_table[] = {
 	{ "ce4100-i2c",		REGS_CE4100 },
 	{ "pxa910-i2c",		REGS_PXA910 },
 	{ "armada-3700-i2c",	REGS_A3700  },
-	{ },
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, i2c_pxa_id_table);
 
@@ -264,6 +265,9 @@ struct pxa_i2c {
 	u32			hs_mask;
 
 	struct i2c_bus_recovery_info recovery;
+	struct pinctrl		*pinctrl;
+	struct pinctrl_state	*pinctrl_default;
+	struct pinctrl_state	*pinctrl_recovery;
 };
 
 #define _IBMR(i2c)	((i2c)->reg_ibmr)
@@ -320,6 +324,7 @@ static void decode_ISR(unsigned int val)
 	decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
 }
 
+#ifdef CONFIG_I2C_PXA_SLAVE
 static const struct bits icr_bits[] = {
 	PXA_BIT(ICR_START,  "START",	NULL),
 	PXA_BIT(ICR_STOP,   "STOP",	NULL),
@@ -338,7 +343,6 @@ static const struct bits icr_bits[] = {
 	PXA_BIT(ICR_UR,     "UR",		"ur"),
 };
 
-#ifdef CONFIG_I2C_PXA_SLAVE
 static void decode_ICR(unsigned int val)
 {
 	decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
@@ -822,7 +826,7 @@ static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
 static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
 {
 	u32 icr;
-	long timeout;
+	long time_left;
 
 	spin_lock_irq(&i2c->lock);
 	i2c->highmode_enter = true;
@@ -833,12 +837,12 @@ static int i2c_pxa_send_mastercode(struct pxa_i2c *i2c)
 	writel(icr, _ICR(i2c));
 
 	spin_unlock_irq(&i2c->lock);
-	timeout = wait_event_timeout(i2c->wait,
-			i2c->highmode_enter == false, HZ * 1);
+	time_left = wait_event_timeout(i2c->wait,
+				       i2c->highmode_enter == false, HZ * 1);
 
 	i2c->highmode_enter = false;
 
-	return (timeout == 0) ? I2C_RETRY : 0;
+	return (time_left == 0) ? I2C_RETRY : 0;
 }
 
 /*
@@ -1046,7 +1050,7 @@ static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
  */
 static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 {
-	long timeout;
+	long time_left;
 	int ret;
 
 	/*
@@ -1091,7 +1095,7 @@ static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 	/*
 	 * The rest of the processing occurs in the interrupt handler.
 	 */
-	timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
+	time_left = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
 	i2c_pxa_stop_message(i2c);
 
 	/*
@@ -1099,7 +1103,7 @@ static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
 	 */
 	ret = i2c->msg_idx;
 
-	if (!timeout && i2c->msg_num) {
+	if (!time_left && i2c->msg_num) {
 		i2c_pxa_scream_blue_murder(i2c, "timeout with active message");
 		i2c_recover_bus(&i2c->adap);
 		ret = I2C_RETRY;
@@ -1150,11 +1154,11 @@ static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
 }
 
 static const struct i2c_algorithm i2c_pxa_algorithm = {
-	.master_xfer	= i2c_pxa_xfer,
-	.functionality	= i2c_pxa_functionality,
+	.xfer = i2c_pxa_xfer,
+	.functionality = i2c_pxa_functionality,
 #ifdef CONFIG_I2C_PXA_SLAVE
-	.reg_slave	= i2c_pxa_slave_reg,
-	.unreg_slave	= i2c_pxa_slave_unreg,
+	.reg_slave = i2c_pxa_slave_reg,
+	.unreg_slave = i2c_pxa_slave_unreg,
 #endif
 };
 
@@ -1240,11 +1244,11 @@ static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
 }
 
 static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
-	.master_xfer	= i2c_pxa_pio_xfer,
-	.functionality	= i2c_pxa_functionality,
+	.xfer = i2c_pxa_pio_xfer,
+	.functionality = i2c_pxa_functionality,
 #ifdef CONFIG_I2C_PXA_SLAVE
-	.reg_slave	= i2c_pxa_slave_reg,
-	.unreg_slave	= i2c_pxa_slave_unreg,
+	.reg_slave = i2c_pxa_slave_reg,
+	.unreg_slave = i2c_pxa_slave_unreg,
 #endif
 };
 
@@ -1252,21 +1256,17 @@ static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
 			    enum pxa_i2c_types *i2c_types)
 {
 	struct device_node *np = pdev->dev.of_node;
-	const struct of_device_id *of_id =
-			of_match_device(i2c_pxa_dt_ids, &pdev->dev);
 
-	if (!of_id)
+	if (!pdev->dev.of_node)
 		return 1;
 
 	/* For device tree we always use the dynamic or alias-assigned ID */
 	i2c->adap.nr = -1;
 
-	if (of_get_property(np, "mrvl,i2c-polling", NULL))
-		i2c->use_pio = 1;
-	if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
-		i2c->fast_mode = 1;
+	i2c->use_pio = of_property_read_bool(np, "mrvl,i2c-polling");
+	i2c->fast_mode = of_property_read_bool(np, "mrvl,i2c-fast-mode");
 
-	*i2c_types = (enum pxa_i2c_types)(of_id->data);
+	*i2c_types = (enum pxa_i2c_types)device_get_match_data(&pdev->dev);
 
 	return 0;
 }
@@ -1302,12 +1302,13 @@ static void i2c_pxa_prepare_recovery(struct i2c_adapter *adap)
 	 */
 	gpiod_set_value(i2c->recovery.scl_gpiod, ibmr & IBMR_SCLS);
 	gpiod_set_value(i2c->recovery.sda_gpiod, ibmr & IBMR_SDAS);
+
+	WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery));
 }
 
 static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap)
 {
 	struct pxa_i2c *i2c = adap->algo_data;
-	struct i2c_bus_recovery_info *bri = adap->bus_recovery_info;
 	u32 isr;
 
 	/*
@@ -1321,7 +1322,7 @@ static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap)
 		i2c_pxa_do_reset(i2c);
 	}
 
-	WARN_ON(pinctrl_select_state(bri->pinctrl, bri->pins_default));
+	WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default));
 
 	dev_dbg(&i2c->adap.dev, "recovery: IBMR 0x%08x ISR 0x%08x\n",
 	        readl(_IBMR(i2c)), readl(_ISR(i2c)));
@@ -1343,20 +1344,76 @@ static int i2c_pxa_init_recovery(struct pxa_i2c *i2c)
 	if (IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
 		return 0;
 
-	bri->pinctrl = devm_pinctrl_get(dev);
-	if (PTR_ERR(bri->pinctrl) == -ENODEV) {
-		bri->pinctrl = NULL;
+	i2c->pinctrl = devm_pinctrl_get(dev);
+	if (PTR_ERR(i2c->pinctrl) == -ENODEV)
+		i2c->pinctrl = NULL;
+	if (IS_ERR(i2c->pinctrl))
+		return PTR_ERR(i2c->pinctrl);
+
+	if (!i2c->pinctrl)
+		return 0;
+
+	i2c->pinctrl_default = pinctrl_lookup_state(i2c->pinctrl,
+						    PINCTRL_STATE_DEFAULT);
+	i2c->pinctrl_recovery = pinctrl_lookup_state(i2c->pinctrl, "recovery");
+
+	if (IS_ERR(i2c->pinctrl_default) || IS_ERR(i2c->pinctrl_recovery)) {
+		dev_info(dev, "missing pinmux recovery information: %ld %ld\n",
+			 PTR_ERR(i2c->pinctrl_default),
+			 PTR_ERR(i2c->pinctrl_recovery));
+		return 0;
+	}
+
+	/*
+	 * Claiming GPIOs can influence the pinmux state, and may glitch the
+	 * I2C bus. Do this carefully.
+	 */
+	bri->scl_gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
+	if (bri->scl_gpiod == ERR_PTR(-EPROBE_DEFER))
+		return -EPROBE_DEFER;
+	if (IS_ERR(bri->scl_gpiod)) {
+		dev_info(dev, "missing scl gpio recovery information: %pe\n",
+			 bri->scl_gpiod);
+		return 0;
+	}
+
+	/*
+	 * We have SCL. Pull SCL low and wait a bit so that SDA glitches
+	 * have no effect.
+	 */
+	gpiod_direction_output(bri->scl_gpiod, 0);
+	udelay(10);
+	bri->sda_gpiod = devm_gpiod_get(dev, "sda", GPIOD_OUT_HIGH_OPEN_DRAIN);
+
+	/* Wait a bit in case of a SDA glitch, and then release SCL. */
+	udelay(10);
+	gpiod_direction_output(bri->scl_gpiod, 1);
+
+	if (bri->sda_gpiod == ERR_PTR(-EPROBE_DEFER))
+		return -EPROBE_DEFER;
+
+	if (IS_ERR(bri->sda_gpiod)) {
+		dev_info(dev, "missing sda gpio recovery information: %pe\n",
+			 bri->sda_gpiod);
 		return 0;
 	}
-	if (IS_ERR(bri->pinctrl))
-		return PTR_ERR(bri->pinctrl);
 
 	bri->prepare_recovery = i2c_pxa_prepare_recovery;
 	bri->unprepare_recovery = i2c_pxa_unprepare_recovery;
+	bri->recover_bus = i2c_generic_scl_recovery;
 
 	i2c->adap.bus_recovery_info = bri;
 
-	return 0;
+	/*
+	 * Claiming GPIOs can change the pinmux state, which confuses the
+	 * pinctrl since pinctrl's idea of the current setting is unaffected
+	 * by the pinmux change caused by claiming the GPIO. Work around that
+	 * by switching pinctrl to the GPIO state here. We do it this way to
+	 * avoid glitching the I2C bus.
+	 */
+	pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery);
+
+	return pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default);
 }
 
 static int i2c_pxa_probe(struct platform_device *dev)
@@ -1364,7 +1421,7 @@ static int i2c_pxa_probe(struct platform_device *dev)
 	struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev);
 	enum pxa_i2c_types i2c_type;
 	struct pxa_i2c *i2c;
-	struct resource *res = NULL;
+	struct resource *res;
 	int ret, irq;
 
 	i2c = devm_kzalloc(&dev->dev, sizeof(struct pxa_i2c), GFP_KERNEL);
@@ -1381,8 +1438,7 @@ static int i2c_pxa_probe(struct platform_device *dev)
 	i2c->adap.dev.of_node = dev->dev.of_node;
 #endif
 
-	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
-	i2c->reg_base = devm_ioremap_resource(&dev->dev, res);
+	i2c->reg_base = devm_platform_get_and_ioremap_resource(dev, 0, &res);
 	if (IS_ERR(i2c->reg_base))
 		return PTR_ERR(i2c->reg_base);
 
@@ -1403,13 +1459,12 @@ static int i2c_pxa_probe(struct platform_device *dev)
 	spin_lock_init(&i2c->lock);
 	init_waitqueue_head(&i2c->wait);
 
-	strlcpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
+	strscpy(i2c->adap.name, "pxa_i2c-i2c", sizeof(i2c->adap.name));
 
 	i2c->clk = devm_clk_get(&dev->dev, NULL);
-	if (IS_ERR(i2c->clk)) {
-		dev_err(&dev->dev, "failed to get the clk: %ld\n", PTR_ERR(i2c->clk));
-		return PTR_ERR(i2c->clk);
-	}
+	if (IS_ERR(i2c->clk))
+		return dev_err_probe(&dev->dev, PTR_ERR(i2c->clk),
+				     "failed to get the clk\n");
 
 	i2c->reg_ibmr = i2c->reg_base + pxa_reg_layout[i2c_type].ibmr;
 	i2c->reg_idbr = i2c->reg_base + pxa_reg_layout[i2c_type].idbr;
@@ -1448,7 +1503,10 @@ static int i2c_pxa_probe(struct platform_device *dev)
 				i2c->adap.name);
 	}
 
-	clk_prepare_enable(i2c->clk);
+	ret = clk_prepare_enable(i2c->clk);
+	if (ret)
+		return dev_err_probe(&dev->dev, ret,
+				     "failed to enable clock\n");
 
 	if (i2c->use_pio) {
 		i2c->adap.algo = &i2c_pxa_pio_algorithm;
@@ -1484,18 +1542,15 @@ ereqirq:
 	return ret;
 }
 
-static int i2c_pxa_remove(struct platform_device *dev)
+static void i2c_pxa_remove(struct platform_device *dev)
 {
 	struct pxa_i2c *i2c = platform_get_drvdata(dev);
 
 	i2c_del_adapter(&i2c->adap);
 
 	clk_disable_unprepare(i2c->clk);
-
-	return 0;
 }
 
-#ifdef CONFIG_PM
 static int i2c_pxa_suspend_noirq(struct device *dev)
 {
 	struct pxa_i2c *i2c = dev_get_drvdata(dev);
@@ -1520,17 +1575,12 @@ static const struct dev_pm_ops i2c_pxa_dev_pm_ops = {
 	.resume_noirq = i2c_pxa_resume_noirq,
 };
 
-#define I2C_PXA_DEV_PM_OPS (&i2c_pxa_dev_pm_ops)
-#else
-#define I2C_PXA_DEV_PM_OPS NULL
-#endif
-
 static struct platform_driver i2c_pxa_driver = {
 	.probe		= i2c_pxa_probe,
 	.remove		= i2c_pxa_remove,
 	.driver		= {
 		.name	= "pxa2xx-i2c",
-		.pm	= I2C_PXA_DEV_PM_OPS,
+		.pm	= pm_sleep_ptr(&i2c_pxa_dev_pm_ops),
 		.of_match_table = i2c_pxa_dt_ids,
 	},
 	.id_table	= i2c_pxa_id_table,
@@ -1546,8 +1596,8 @@ static void __exit i2c_adap_pxa_exit(void)
 	platform_driver_unregister(&i2c_pxa_driver);
 }
 
+MODULE_DESCRIPTION("Intel PXA2XX I2C adapter");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:pxa2xx-i2c");
 
 subsys_initcall(i2c_adap_pxa_init);
 module_exit(i2c_adap_pxa_exit);