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authorWolfram Sang <wsa@the-dreams.de>2017-11-01 23:44:52 +0100
committerWolfram Sang <wsa@the-dreams.de>2017-11-01 23:45:46 +0100
commit4ee045f4e9b73c4635ceedbb1ee40e0b3ecbdbcc (patch)
treef75e20907a3dc01e780ca75b1696f7d30c179944 /drivers
parent93367bfca98f36cece57c01dbce6ea1b4ac58245 (diff)
parent05c74778858d7d9907d607172fcc9646b70b6364 (diff)
downloadlinux-4ee045f4e9b73c4635ceedbb1ee40e0b3ecbdbcc.tar.bz2
Merge branch 'for-wolfram' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio into i2c/for-4.15
Refactor i2c-gpio and its users to use gpiod. Done by GPIO maintainer LinusW.
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpio/gpiolib.c13
-rw-r--r--drivers/i2c/busses/i2c-gpio.c212
-rw-r--r--drivers/mfd/sm501.c49
3 files changed, 144 insertions, 130 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index eb80dac4e26a..c952ef1b2f46 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -3264,8 +3264,21 @@ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id,
if (lflags & GPIO_ACTIVE_LOW)
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
+
if (lflags & GPIO_OPEN_DRAIN)
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
+ else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) {
+ /*
+ * This enforces open drain mode from the consumer side.
+ * This is necessary for some busses like I2C, but the lookup
+ * should *REALLY* have specified them as open drain in the
+ * first place, so print a little warning here.
+ */
+ set_bit(FLAG_OPEN_DRAIN, &desc->flags);
+ gpiod_warn(desc,
+ "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n");
+ }
+
if (lflags & GPIO_OPEN_SOURCE)
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
if (lflags & GPIO_SLEEP_MAY_LOOSE_VALUE)
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index 0ef8fcc6ac3a..d80ea6ce91bb 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -14,27 +14,17 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
#include <linux/of.h>
-#include <linux/of_gpio.h>
struct i2c_gpio_private_data {
+ struct gpio_desc *sda;
+ struct gpio_desc *scl;
struct i2c_adapter adap;
struct i2c_algo_bit_data bit_data;
struct i2c_gpio_platform_data pdata;
};
-/* Toggle SDA by changing the direction of the pin */
-static void i2c_gpio_setsda_dir(void *data, int state)
-{
- struct i2c_gpio_platform_data *pdata = data;
-
- if (state)
- gpio_direction_input(pdata->sda_pin);
- else
- gpio_direction_output(pdata->sda_pin, 0);
-}
-
/*
* Toggle SDA by changing the output value of the pin. This is only
* valid for pins configured as open drain (i.e. setting the value
@@ -42,20 +32,9 @@ static void i2c_gpio_setsda_dir(void *data, int state)
*/
static void i2c_gpio_setsda_val(void *data, int state)
{
- struct i2c_gpio_platform_data *pdata = data;
-
- gpio_set_value(pdata->sda_pin, state);
-}
-
-/* Toggle SCL by changing the direction of the pin. */
-static void i2c_gpio_setscl_dir(void *data, int state)
-{
- struct i2c_gpio_platform_data *pdata = data;
+ struct i2c_gpio_private_data *priv = data;
- if (state)
- gpio_direction_input(pdata->scl_pin);
- else
- gpio_direction_output(pdata->scl_pin, 0);
+ gpiod_set_value(priv->sda, state);
}
/*
@@ -66,44 +45,23 @@ static void i2c_gpio_setscl_dir(void *data, int state)
*/
static void i2c_gpio_setscl_val(void *data, int state)
{
- struct i2c_gpio_platform_data *pdata = data;
+ struct i2c_gpio_private_data *priv = data;
- gpio_set_value(pdata->scl_pin, state);
+ gpiod_set_value(priv->scl, state);
}
static int i2c_gpio_getsda(void *data)
{
- struct i2c_gpio_platform_data *pdata = data;
+ struct i2c_gpio_private_data *priv = data;
- return gpio_get_value(pdata->sda_pin);
+ return gpiod_get_value(priv->sda);
}
static int i2c_gpio_getscl(void *data)
{
- struct i2c_gpio_platform_data *pdata = data;
-
- return gpio_get_value(pdata->scl_pin);
-}
-
-static int of_i2c_gpio_get_pins(struct device_node *np,
- unsigned int *sda_pin, unsigned int *scl_pin)
-{
- if (of_gpio_count(np) < 2)
- return -ENODEV;
-
- *sda_pin = of_get_gpio(np, 0);
- *scl_pin = of_get_gpio(np, 1);
-
- if (*sda_pin == -EPROBE_DEFER || *scl_pin == -EPROBE_DEFER)
- return -EPROBE_DEFER;
-
- if (!gpio_is_valid(*sda_pin) || !gpio_is_valid(*scl_pin)) {
- pr_err("%pOF: invalid GPIO pins, sda=%d/scl=%d\n",
- np, *sda_pin, *scl_pin);
- return -ENODEV;
- }
+ struct i2c_gpio_private_data *priv = data;
- return 0;
+ return gpiod_get_value(priv->scl);
}
static void of_i2c_gpio_get_props(struct device_node *np,
@@ -124,72 +82,105 @@ static void of_i2c_gpio_get_props(struct device_node *np,
of_property_read_bool(np, "i2c-gpio,scl-output-only");
}
+static struct gpio_desc *i2c_gpio_get_desc(struct device *dev,
+ const char *con_id,
+ unsigned int index,
+ enum gpiod_flags gflags)
+{
+ struct gpio_desc *retdesc;
+ int ret;
+
+ retdesc = devm_gpiod_get(dev, con_id, gflags);
+ if (!IS_ERR(retdesc)) {
+ dev_dbg(dev, "got GPIO from name %s\n", con_id);
+ return retdesc;
+ }
+
+ retdesc = devm_gpiod_get_index(dev, NULL, index, gflags);
+ if (!IS_ERR(retdesc)) {
+ dev_dbg(dev, "got GPIO from index %u\n", index);
+ return retdesc;
+ }
+
+ ret = PTR_ERR(retdesc);
+
+ /* FIXME: hack in the old code, is this really necessary? */
+ if (ret == -EINVAL)
+ retdesc = ERR_PTR(-EPROBE_DEFER);
+
+ /* This happens if the GPIO driver is not yet probed, let's defer */
+ if (ret == -ENOENT)
+ retdesc = ERR_PTR(-EPROBE_DEFER);
+
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "error trying to get descriptor: %d\n", ret);
+
+ return retdesc;
+}
+
static int i2c_gpio_probe(struct platform_device *pdev)
{
struct i2c_gpio_private_data *priv;
struct i2c_gpio_platform_data *pdata;
struct i2c_algo_bit_data *bit_data;
struct i2c_adapter *adap;
- unsigned int sda_pin, scl_pin;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ enum gpiod_flags gflags;
int ret;
- /* First get the GPIO pins; if it fails, we'll defer the probe. */
- if (pdev->dev.of_node) {
- ret = of_i2c_gpio_get_pins(pdev->dev.of_node,
- &sda_pin, &scl_pin);
- if (ret)
- return ret;
- } else {
- if (!dev_get_platdata(&pdev->dev))
- return -ENXIO;
- pdata = dev_get_platdata(&pdev->dev);
- sda_pin = pdata->sda_pin;
- scl_pin = pdata->scl_pin;
- }
-
- ret = devm_gpio_request(&pdev->dev, sda_pin, "sda");
- if (ret) {
- if (ret == -EINVAL)
- ret = -EPROBE_DEFER; /* Try again later */
- return ret;
- }
- ret = devm_gpio_request(&pdev->dev, scl_pin, "scl");
- if (ret) {
- if (ret == -EINVAL)
- ret = -EPROBE_DEFER; /* Try again later */
- return ret;
- }
-
- priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
+
adap = &priv->adap;
bit_data = &priv->bit_data;
pdata = &priv->pdata;
- if (pdev->dev.of_node) {
- pdata->sda_pin = sda_pin;
- pdata->scl_pin = scl_pin;
- of_i2c_gpio_get_props(pdev->dev.of_node, pdata);
+ if (np) {
+ of_i2c_gpio_get_props(np, pdata);
} else {
- memcpy(pdata, dev_get_platdata(&pdev->dev), sizeof(*pdata));
+ /*
+ * If all platform data settings are zero it is OK
+ * to not provide any platform data from the board.
+ */
+ if (dev_get_platdata(dev))
+ memcpy(pdata, dev_get_platdata(dev), sizeof(*pdata));
}
- if (pdata->sda_is_open_drain) {
- gpio_direction_output(pdata->sda_pin, 1);
- bit_data->setsda = i2c_gpio_setsda_val;
- } else {
- gpio_direction_input(pdata->sda_pin);
- bit_data->setsda = i2c_gpio_setsda_dir;
- }
+ /*
+ * First get the GPIO pins; if it fails, we'll defer the probe.
+ * If the SDA line is marked from platform data or device tree as
+ * "open drain" it means something outside of our control is making
+ * this line being handled as open drain, and we should just handle
+ * it as any other output. Else we enforce open drain as this is
+ * required for an I2C bus.
+ */
+ if (pdata->sda_is_open_drain)
+ gflags = GPIOD_OUT_HIGH;
+ else
+ gflags = GPIOD_OUT_HIGH_OPEN_DRAIN;
+ priv->sda = i2c_gpio_get_desc(dev, "sda", 0, gflags);
+ if (IS_ERR(priv->sda))
+ return PTR_ERR(priv->sda);
+
+ /*
+ * If the SCL line is marked from platform data or device tree as
+ * "open drain" it means something outside of our control is making
+ * this line being handled as open drain, and we should just handle
+ * it as any other output. Else we enforce open drain as this is
+ * required for an I2C bus.
+ */
+ if (pdata->scl_is_open_drain)
+ gflags = GPIOD_OUT_LOW;
+ else
+ gflags = GPIOD_OUT_LOW_OPEN_DRAIN;
+ priv->scl = i2c_gpio_get_desc(dev, "scl", 1, gflags);
+ if (IS_ERR(priv->scl))
+ return PTR_ERR(priv->scl);
- if (pdata->scl_is_open_drain || pdata->scl_is_output_only) {
- gpio_direction_output(pdata->scl_pin, 1);
- bit_data->setscl = i2c_gpio_setscl_val;
- } else {
- gpio_direction_input(pdata->scl_pin);
- bit_data->setscl = i2c_gpio_setscl_dir;
- }
+ bit_data->setsda = i2c_gpio_setsda_val;
+ bit_data->setscl = i2c_gpio_setscl_val;
if (!pdata->scl_is_output_only)
bit_data->getscl = i2c_gpio_getscl;
@@ -207,18 +198,18 @@ static int i2c_gpio_probe(struct platform_device *pdev)
else
bit_data->timeout = HZ / 10; /* 100 ms */
- bit_data->data = pdata;
+ bit_data->data = priv;
adap->owner = THIS_MODULE;
- if (pdev->dev.of_node)
- strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
+ if (np)
+ strlcpy(adap->name, dev_name(dev), sizeof(adap->name));
else
snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
adap->algo_data = bit_data;
adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
- adap->dev.parent = &pdev->dev;
- adap->dev.of_node = pdev->dev.of_node;
+ adap->dev.parent = dev;
+ adap->dev.of_node = np;
adap->nr = pdev->id;
ret = i2c_bit_add_numbered_bus(adap);
@@ -227,8 +218,13 @@ static int i2c_gpio_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, priv);
- dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n",
- pdata->sda_pin, pdata->scl_pin,
+ /*
+ * FIXME: using global GPIO numbers is not helpful. If/when we
+ * get accessors to get the actual name of the GPIO line,
+ * from the descriptor, then provide that instead.
+ */
+ dev_info(dev, "using lines %u (SDA) and %u (SCL%s)\n",
+ desc_to_gpio(priv->sda), desc_to_gpio(priv->scl),
pdata->scl_is_output_only
? ", no clock stretching" : "");
diff --git a/drivers/mfd/sm501.c b/drivers/mfd/sm501.c
index 40534352e574..ad774161a22d 100644
--- a/drivers/mfd/sm501.c
+++ b/drivers/mfd/sm501.c
@@ -20,6 +20,7 @@
#include <linux/platform_device.h>
#include <linux/pci.h>
#include <linux/i2c-gpio.h>
+#include <linux/gpio/machine.h>
#include <linux/slab.h>
#include <linux/sm501.h>
@@ -1107,14 +1108,6 @@ static void sm501_gpio_remove(struct sm501_devdata *sm)
kfree(gpio->regs_res);
}
-static inline int sm501_gpio_pin2nr(struct sm501_devdata *sm, unsigned int pin)
-{
- struct sm501_gpio *gpio = &sm->gpio;
- int base = (pin < 32) ? gpio->low.gpio.base : gpio->high.gpio.base;
-
- return (pin % 32) + base;
-}
-
static inline int sm501_gpio_isregistered(struct sm501_devdata *sm)
{
return sm->gpio.registered;
@@ -1129,11 +1122,6 @@ static inline void sm501_gpio_remove(struct sm501_devdata *sm)
{
}
-static inline int sm501_gpio_pin2nr(struct sm501_devdata *sm, unsigned int pin)
-{
- return -1;
-}
-
static inline int sm501_gpio_isregistered(struct sm501_devdata *sm)
{
return 0;
@@ -1145,20 +1133,37 @@ static int sm501_register_gpio_i2c_instance(struct sm501_devdata *sm,
{
struct i2c_gpio_platform_data *icd;
struct platform_device *pdev;
+ struct gpiod_lookup_table *lookup;
pdev = sm501_create_subdev(sm, "i2c-gpio", 0,
sizeof(struct i2c_gpio_platform_data));
if (!pdev)
return -ENOMEM;
- icd = dev_get_platdata(&pdev->dev);
-
- /* We keep the pin_sda and pin_scl fields relative in case the
- * same platform data is passed to >1 SM501.
- */
+ /* Create a gpiod lookup using gpiochip-local offsets */
+ lookup = devm_kzalloc(&pdev->dev,
+ sizeof(*lookup) + 3 * sizeof(struct gpiod_lookup),
+ GFP_KERNEL);
+ lookup->dev_id = "i2c-gpio";
+ if (iic->pin_sda < 32)
+ lookup->table[0].chip_label = "SM501-LOW";
+ else
+ lookup->table[0].chip_label = "SM501-HIGH";
+ lookup->table[0].chip_hwnum = iic->pin_sda % 32;
+ lookup->table[0].con_id = NULL;
+ lookup->table[0].idx = 0;
+ lookup->table[0].flags = GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN;
+ if (iic->pin_scl < 32)
+ lookup->table[1].chip_label = "SM501-LOW";
+ else
+ lookup->table[1].chip_label = "SM501-HIGH";
+ lookup->table[1].chip_hwnum = iic->pin_scl % 32;
+ lookup->table[1].con_id = NULL;
+ lookup->table[1].idx = 1;
+ lookup->table[1].flags = GPIO_ACTIVE_HIGH | GPIO_OPEN_DRAIN;
+ gpiod_add_lookup_table(lookup);
- icd->sda_pin = sm501_gpio_pin2nr(sm, iic->pin_sda);
- icd->scl_pin = sm501_gpio_pin2nr(sm, iic->pin_scl);
+ icd = dev_get_platdata(&pdev->dev);
icd->timeout = iic->timeout;
icd->udelay = iic->udelay;
@@ -1170,9 +1175,9 @@ static int sm501_register_gpio_i2c_instance(struct sm501_devdata *sm,
pdev->id = iic->bus_num;
- dev_info(sm->dev, "registering i2c-%d: sda=%d (%d), scl=%d (%d)\n",
+ dev_info(sm->dev, "registering i2c-%d: sda=%d, scl=%d\n",
iic->bus_num,
- icd->sda_pin, iic->pin_sda, icd->scl_pin, iic->pin_scl);
+ iic->pin_sda, iic->pin_scl);
return sm501_register_device(sm, pdev);
}