Merge branch 'i2c-mux/for-next' of https://github.com/peda-r/i2c-mux into i2c/for-5.3

I realize that there are changes in drivers/i2c/busses/i2c-i801.c that strictly
speaking don't belong here, but I hope you don't mind. These changes are all
about the interaction with the i2c-mux-gpio code, and I did a test-merge a few
days ago w/o conflicts.

Anyway, the GPIO-work from Linus Walleij (with help from Serge Semin) in the
i2c-mux-gpio and i2c-arb-gpio-challenge drivers is the main feature.

5 files changed, 91 insertions, 150 deletions

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 82005291bcf3..763a8d6cc336 100644
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -109,7 +109,7 @@
 #include <linux/pm_runtime.h>
 
 #if IS_ENABLED(CONFIG_I2C_MUX_GPIO) && defined CONFIG_DMI
-#include <linux/gpio.h>
+#include <linux/gpio/machine.h>
 #include <linux/platform_data/i2c-mux-gpio.h>
 #endif
 
@@ -278,6 +278,7 @@ struct i801_priv {
 #if IS_ENABLED(CONFIG_I2C_MUX_GPIO) && defined CONFIG_DMI
 	const struct i801_mux_config *mux_drvdata;
 	struct platform_device *mux_pdev;
+	struct gpiod_lookup_table *lookup;
 #endif
 	struct platform_device *tco_pdev;
 
@@ -1406,7 +1407,8 @@ static int i801_add_mux(struct i801_priv *priv)
 	struct device *dev = &priv->adapter.dev;
 	const struct i801_mux_config *mux_config;
 	struct i2c_mux_gpio_platform_data gpio_data;
-	int err;
+	struct gpiod_lookup_table *lookup;
+	int err, i;
 
 	if (!priv->mux_drvdata)
 		return 0;
@@ -1418,17 +1420,36 @@ static int i801_add_mux(struct i801_priv *priv)
 	gpio_data.values = mux_config->values;
 	gpio_data.n_values = mux_config->n_values;
 	gpio_data.classes = mux_config->classes;
-	gpio_data.gpio_chip = mux_config->gpio_chip;
-	gpio_data.gpios = mux_config->gpios;
-	gpio_data.n_gpios = mux_config->n_gpios;
 	gpio_data.idle = I2C_MUX_GPIO_NO_IDLE;
 
-	/* Register the mux device */
+	/* Register GPIO descriptor lookup table */
+	lookup = devm_kzalloc(dev,
+			      struct_size(lookup, table, mux_config->n_gpios),
+			      GFP_KERNEL);
+	if (!lookup)
+		return -ENOMEM;
+	lookup->dev_id = "i2c-mux-gpio";
+	for (i = 0; i < mux_config->n_gpios; i++) {
+		lookup->table[i].chip_label = mux_config->gpio_chip;
+		lookup->table[i].chip_hwnum = mux_config->gpios[i];
+		lookup->table[i].con_id = "mux";
+	}
+	gpiod_add_lookup_table(lookup);
+	priv->lookup = lookup;
+
+	/*
+	 * Register the mux device, we use PLATFORM_DEVID_NONE here
+	 * because since we are referring to the GPIO chip by name we are
+	 * anyways in deep trouble if there is more than one of these
+	 * devices, and there should likely only be one platform controller
+	 * hub.
+	 */
 	priv->mux_pdev = platform_device_register_data(dev, "i2c-mux-gpio",
-				PLATFORM_DEVID_AUTO, &gpio_data,
+				PLATFORM_DEVID_NONE, &gpio_data,
 				sizeof(struct i2c_mux_gpio_platform_data));
 	if (IS_ERR(priv->mux_pdev)) {
 		err = PTR_ERR(priv->mux_pdev);
+		gpiod_remove_lookup_table(lookup);
 		priv->mux_pdev = NULL;
 		dev_err(dev, "Failed to register i2c-mux-gpio device\n");
 		return err;
@@ -1441,6 +1462,8 @@ static void i801_del_mux(struct i801_priv *priv)
 {
 	if (priv->mux_pdev)
 		platform_device_unregister(priv->mux_pdev);
+	if (priv->lookup)
+		gpiod_remove_lookup_table(priv->lookup);
 }
 
 static unsigned int i801_get_adapter_class(struct i801_priv *priv)
diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c
index 603252fa1284..774507b54b57 100644
--- a/drivers/i2c/i2c-mux.c
+++ b/drivers/i2c/i2c-mux.c
@@ -26,6 +26,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/slab.h>
+#include <linux/sysfs.h>
 
 /* multiplexer per channel data */
 struct i2c_mux_priv {
@@ -243,8 +244,7 @@ struct i2c_mux_core *i2c_mux_alloc(struct i2c_adapter *parent,
 {
 	struct i2c_mux_core *muxc;
 
-	muxc = devm_kzalloc(dev, sizeof(*muxc)
-			    + max_adapters * sizeof(muxc->adapter[0])
+	muxc = devm_kzalloc(dev, struct_size(muxc, adapter, max_adapters)
 			    + sizeof_priv, GFP_KERNEL);
 	if (!muxc)
 		return NULL;
diff --git a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
index 812b8cff265f..a664f637bc3d 100644
--- a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
+++ b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
@@ -15,12 +15,11 @@
  */
 
 #include <linux/delay.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/kernel.h>
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
 #include <linux/module.h>
-#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
@@ -28,22 +27,16 @@
 /**
  * struct i2c_arbitrator_data - Driver data for I2C arbitrator
  *
- * @our_gpio: GPIO we'll use to claim.
- * @our_gpio_release: 0 if active high; 1 if active low; AKA if the GPIO ==
- *   this then consider it released.
- * @their_gpio: GPIO that the other side will use to claim.
- * @their_gpio_release: 0 if active high; 1 if active low; AKA if the GPIO ==
- *   this then consider it released.
+ * @our_gpio: GPIO descriptor we'll use to claim.
+ * @their_gpio: GPIO descriptor that the other side will use to claim.
  * @slew_delay_us: microseconds to wait for a GPIO to go high.
  * @wait_retry_us: we'll attempt another claim after this many microseconds.
  * @wait_free_us: we'll give up after this many microseconds.
  */
 
 struct i2c_arbitrator_data {
-	int our_gpio;
-	int our_gpio_release;
-	int their_gpio;
-	int their_gpio_release;
+	struct gpio_desc *our_gpio;
+	struct gpio_desc *their_gpio;
 	unsigned int slew_delay_us;
 	unsigned int wait_retry_us;
 	unsigned int wait_free_us;
@@ -64,15 +57,15 @@ static int i2c_arbitrator_select(struct i2c_mux_core *muxc, u32 chan)
 	stop_time = jiffies + usecs_to_jiffies(arb->wait_free_us) + 1;
 	do {
 		/* Indicate that we want to claim the bus */
-		gpio_set_value(arb->our_gpio, !arb->our_gpio_release);
+		gpiod_set_value(arb->our_gpio, 1);
 		udelay(arb->slew_delay_us);
 
 		/* Wait for the other master to release it */
 		stop_retry = jiffies + usecs_to_jiffies(arb->wait_retry_us) + 1;
 		while (time_before(jiffies, stop_retry)) {
-			int gpio_val = !!gpio_get_value(arb->their_gpio);
+			int gpio_val = gpiod_get_value(arb->their_gpio);
 
-			if (gpio_val == arb->their_gpio_release) {
+			if (!gpio_val) {
 				/* We got it, so return */
 				return 0;
 			}
@@ -81,13 +74,13 @@ static int i2c_arbitrator_select(struct i2c_mux_core *muxc, u32 chan)
 		}
 
 		/* It didn't release, so give up, wait, and try again */
-		gpio_set_value(arb->our_gpio, arb->our_gpio_release);
+		gpiod_set_value(arb->our_gpio, 0);
 
 		usleep_range(arb->wait_retry_us, arb->wait_retry_us * 2);
 	} while (time_before(jiffies, stop_time));
 
 	/* Give up, release our claim */
-	gpio_set_value(arb->our_gpio, arb->our_gpio_release);
+	gpiod_set_value(arb->our_gpio, 0);
 	udelay(arb->slew_delay_us);
 	dev_err(muxc->dev, "Could not claim bus, timeout\n");
 	return -EBUSY;
@@ -103,7 +96,7 @@ static int i2c_arbitrator_deselect(struct i2c_mux_core *muxc, u32 chan)
 	const struct i2c_arbitrator_data *arb = i2c_mux_priv(muxc);
 
 	/* Release the bus and wait for the other master to notice */
-	gpio_set_value(arb->our_gpio, arb->our_gpio_release);
+	gpiod_set_value(arb->our_gpio, 0);
 	udelay(arb->slew_delay_us);
 
 	return 0;
@@ -116,8 +109,7 @@ static int i2c_arbitrator_probe(struct platform_device *pdev)
 	struct device_node *parent_np;
 	struct i2c_mux_core *muxc;
 	struct i2c_arbitrator_data *arb;
-	enum of_gpio_flags gpio_flags;
-	unsigned long out_init;
+	struct gpio_desc *dummy;
 	int ret;
 
 	/* We only support probing from device tree; no platform_data */
@@ -138,45 +130,28 @@ static int i2c_arbitrator_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, muxc);
 
-	/* Request GPIOs */
-	ret = of_get_named_gpio_flags(np, "our-claim-gpio", 0, &gpio_flags);
-	if (!gpio_is_valid(ret)) {
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "Error getting our-claim-gpio\n");
-		return ret;
-	}
-	arb->our_gpio = ret;
-	arb->our_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
-	out_init = (gpio_flags & OF_GPIO_ACTIVE_LOW) ?
-		GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
-	ret = devm_gpio_request_one(dev, arb->our_gpio, out_init,
-				    "our-claim-gpio");
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "Error requesting our-claim-gpio\n");
-		return ret;
+	/* Request GPIOs, our GPIO as unclaimed to begin with */
+	arb->our_gpio = devm_gpiod_get(dev, "our-claim", GPIOD_OUT_LOW);
+	if (IS_ERR(arb->our_gpio)) {
+		dev_err(dev, "could not get \"our-claim\" GPIO (%ld)\n",
+			PTR_ERR(arb->our_gpio));
+		return PTR_ERR(arb->our_gpio);
 	}
 
-	ret = of_get_named_gpio_flags(np, "their-claim-gpios", 0, &gpio_flags);
-	if (!gpio_is_valid(ret)) {
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "Error getting their-claim-gpio\n");
-		return ret;
-	}
-	arb->their_gpio = ret;
-	arb->their_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
-	ret = devm_gpio_request_one(dev, arb->their_gpio, GPIOF_IN,
-				    "their-claim-gpio");
-	if (ret) {
-		if (ret != -EPROBE_DEFER)
-			dev_err(dev, "Error requesting their-claim-gpio\n");
-		return ret;
+	arb->their_gpio = devm_gpiod_get(dev, "their-claim", GPIOD_IN);
+	if (IS_ERR(arb->their_gpio)) {
+		dev_err(dev, "could not get \"their-claim\" GPIO (%ld)\n",
+			PTR_ERR(arb->their_gpio));
+		return PTR_ERR(arb->their_gpio);
 	}
 
 	/* At the moment we only support a single two master (us + 1 other) */
-	if (gpio_is_valid(of_get_named_gpio(np, "their-claim-gpios", 1))) {
+	dummy = devm_gpiod_get_index(dev, "their-claim", 1, GPIOD_IN);
+	if (!IS_ERR(dummy)) {
 		dev_err(dev, "Only one other master is supported\n");
 		return -EINVAL;
+	} else if (PTR_ERR(dummy) == -EPROBE_DEFER) {
+		return -EPROBE_DEFER;
 	}
 
 	/* Arbitration parameters */
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
index 13882a2a4f60..fd482feafb19 100644
--- a/drivers/i2c/muxes/i2c-mux-gpio.c
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -14,13 +14,14 @@
 #include <linux/platform_device.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/gpio.h>
+#include <linux/bits.h>
+#include <linux/gpio/consumer.h>
+/* FIXME: stop poking around inside gpiolib */
 #include "../../gpio/gpiolib.h"
-#include <linux/of_gpio.h>
 
 struct gpiomux {
 	struct i2c_mux_gpio_platform_data data;
-	unsigned gpio_base;
+	int ngpios;
 	struct gpio_desc **gpios;
 };
 
@@ -30,8 +31,7 @@ static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
 
 	values[0] = val;
 
-	gpiod_set_array_value_cansleep(mux->data.n_gpios, mux->gpios, NULL,
-				       values);
+	gpiod_set_array_value_cansleep(mux->ngpios, mux->gpios, NULL, values);
 }
 
 static int i2c_mux_gpio_select(struct i2c_mux_core *muxc, u32 chan)
@@ -52,12 +52,6 @@ static int i2c_mux_gpio_deselect(struct i2c_mux_core *muxc, u32 chan)
 	return 0;
 }
 
-static int match_gpio_chip_by_label(struct gpio_chip *chip,
-					      void *data)
-{
-	return !strcmp(chip->label, data);
-}
-
 #ifdef CONFIG_OF
 static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
 					struct platform_device *pdev)
@@ -65,8 +59,8 @@ static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
 	struct device_node *np = pdev->dev.of_node;
 	struct device_node *adapter_np, *child;
 	struct i2c_adapter *adapter;
-	unsigned *values, *gpios;
-	int i = 0, ret;
+	unsigned *values;
+	int i = 0;
 
 	if (!np)
 		return -ENODEV;
@@ -103,29 +97,6 @@ static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
 	if (of_property_read_u32(np, "idle-state", &mux->data.idle))
 		mux->data.idle = I2C_MUX_GPIO_NO_IDLE;
 
-	mux->data.n_gpios = of_gpio_named_count(np, "mux-gpios");
-	if (mux->data.n_gpios < 0) {
-		dev_err(&pdev->dev, "Missing mux-gpios property in the DT.\n");
-		return -EINVAL;
-	}
-
-	gpios = devm_kcalloc(&pdev->dev,
-			     mux->data.n_gpios, sizeof(*mux->data.gpios),
-			     GFP_KERNEL);
-	if (!gpios) {
-		dev_err(&pdev->dev, "Cannot allocate gpios array");
-		return -ENOMEM;
-	}
-
-	for (i = 0; i < mux->data.n_gpios; i++) {
-		ret = of_get_named_gpio(np, "mux-gpios", i);
-		if (ret < 0)
-			return ret;
-		gpios[i] = ret;
-	}
-
-	mux->data.gpios = gpios;
-
 	return 0;
 }
 #else
@@ -142,8 +113,8 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
 	struct gpiomux *mux;
 	struct i2c_adapter *parent;
 	struct i2c_adapter *root;
-	unsigned initial_state, gpio_base;
-	int i, ret;
+	unsigned initial_state;
+	int i, ngpios, ret;
 
 	mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
 	if (!mux)
@@ -158,29 +129,19 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
 			sizeof(mux->data));
 	}
 
-	/*
-	 * If a GPIO chip name is provided, the GPIO pin numbers provided are
-	 * relative to its base GPIO number. Otherwise they are absolute.
-	 */
-	if (mux->data.gpio_chip) {
-		struct gpio_chip *gpio;
-
-		gpio = gpiochip_find(mux->data.gpio_chip,
-				     match_gpio_chip_by_label);
-		if (!gpio)
-			return -EPROBE_DEFER;
-
-		gpio_base = gpio->base;
-	} else {
-		gpio_base = 0;
+	ngpios = gpiod_count(&pdev->dev, "mux");
+	if (ngpios <= 0) {
+		dev_err(&pdev->dev, "no valid gpios provided\n");
+		return ngpios ?: -EINVAL;
 	}
+	mux->ngpios = ngpios;
 
 	parent = i2c_get_adapter(mux->data.parent);
 	if (!parent)
 		return -EPROBE_DEFER;
 
 	muxc = i2c_mux_alloc(parent, &pdev->dev, mux->data.n_values,
-			     mux->data.n_gpios * sizeof(*mux->gpios), 0,
+			     ngpios * sizeof(*mux->gpios), 0,
 			     i2c_mux_gpio_select, NULL);
 	if (!muxc) {
 		ret = -ENOMEM;
@@ -194,7 +155,6 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
 	root = i2c_root_adapter(&parent->dev);
 
 	muxc->mux_locked = true;
-	mux->gpio_base = gpio_base;
 
 	if (mux->data.idle != I2C_MUX_GPIO_NO_IDLE) {
 		initial_state = mux->data.idle;
@@ -203,34 +163,28 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
 		initial_state = mux->data.values[0];
 	}
 
-	for (i = 0; i < mux->data.n_gpios; i++) {
+	for (i = 0; i < ngpios; i++) {
 		struct device *gpio_dev;
-		struct gpio_desc *gpio_desc;
-
-		ret = gpio_request(gpio_base + mux->data.gpios[i], "i2c-mux-gpio");
-		if (ret) {
-			dev_err(&pdev->dev, "Failed to request GPIO %d\n",
-				mux->data.gpios[i]);
-			goto err_request_gpio;
+		struct gpio_desc *gpiod;
+		enum gpiod_flags flag;
+
+		if (initial_state & BIT(i))
+			flag = GPIOD_OUT_HIGH;
+		else
+			flag = GPIOD_OUT_LOW;
+		gpiod = devm_gpiod_get_index(&pdev->dev, "mux", i, flag);
+		if (IS_ERR(gpiod)) {
+			ret = PTR_ERR(gpiod);
+			goto alloc_failed;
 		}
 
-		ret = gpio_direction_output(gpio_base + mux->data.gpios[i],
-					    initial_state & (1 << i));
-		if (ret) {
-			dev_err(&pdev->dev,
-				"Failed to set direction of GPIO %d to output\n",
-				mux->data.gpios[i]);
-			i++;	/* gpio_request above succeeded, so must free */
-			goto err_request_gpio;
-		}
-
-		gpio_desc = gpio_to_desc(gpio_base + mux->data.gpios[i]);
-		mux->gpios[i] = gpio_desc;
+		mux->gpios[i] = gpiod;
 
 		if (!muxc->mux_locked)
 			continue;
 
-		gpio_dev = &gpio_desc->gdev->dev;
+		/* FIXME: find a proper way to access the GPIO device */
+		gpio_dev = &gpiod->gdev->dev;
 		muxc->mux_locked = i2c_root_adapter(gpio_dev) == root;
 	}
 
@@ -253,10 +207,6 @@ static int i2c_mux_gpio_probe(struct platform_device *pdev)
 
 add_adapter_failed:
 	i2c_mux_del_adapters(muxc);
-	i = mux->data.n_gpios;
-err_request_gpio:
-	for (; i > 0; i--)
-		gpio_free(gpio_base + mux->data.gpios[i - 1]);
 alloc_failed:
 	i2c_put_adapter(parent);
 
@@ -266,14 +216,8 @@ alloc_failed:
 static int i2c_mux_gpio_remove(struct platform_device *pdev)
 {
 	struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
-	struct gpiomux *mux = i2c_mux_priv(muxc);
-	int i;
 
 	i2c_mux_del_adapters(muxc);
-
-	for (i = 0; i < mux->data.n_gpios; i++)
-		gpio_free(mux->gpio_base + mux->data.gpios[i]);
-
 	i2c_put_adapter(muxc->parent);
 
 	return 0;
diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c
index cc6818aabab5..ff3e8c9d4dd8 100644
--- a/drivers/i2c/muxes/i2c-mux-pinctrl.c
+++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c
@@ -27,7 +27,7 @@
 
 struct i2c_mux_pinctrl {
 	struct pinctrl *pinctrl;
-	struct pinctrl_state **states;
+	struct pinctrl_state *states[];
 };
 
 static int i2c_mux_pinctrl_select(struct i2c_mux_core *muxc, u32 chan)
@@ -104,14 +104,13 @@ static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
 		return PTR_ERR(parent);
 
 	muxc = i2c_mux_alloc(parent, dev, num_names,
-			     sizeof(*mux) + num_names * sizeof(*mux->states),
+			     struct_size(mux, states, num_names),
 			     0, i2c_mux_pinctrl_select, NULL);
 	if (!muxc) {
 		ret = -ENOMEM;
 		goto err_put_parent;
 	}
 	mux = i2c_mux_priv(muxc);
-	mux->states = (struct pinctrl_state **)(mux + 1);
 
 	platform_set_drvdata(pdev, muxc);