summaryrefslogtreecommitdiffstats
path: root/drivers/i2c/muxes
diff options
context:
space:
mode:
authorLinus Walleij <linus.walleij@linaro.org>2019-06-18 12:58:33 +0200
committerPeter Rosin <peda@axentia.se>2019-06-22 07:01:34 +0200
commitd308dfbf62eff897d71968d764f21a78678ee0a5 (patch)
treed70706269e586a3e7450b9890f092dab1a5bc1d5 /drivers/i2c/muxes
parent90af27317b63403bce3874566b71883fc1e1f459 (diff)
downloadlinux-d308dfbf62eff897d71968d764f21a78678ee0a5.tar.gz
linux-d308dfbf62eff897d71968d764f21a78678ee0a5.tar.bz2
linux-d308dfbf62eff897d71968d764f21a78678ee0a5.zip
i2c: mux/i801: Switch to use descriptor passing
This switches the i801 GPIO mux to use GPIO descriptors for handling the GPIO lines. The previous hack which was reaching inside the GPIO chips etc cannot live on. We pass descriptors along with the GPIO mux device at creation instead. The GPIO mux was only used by way of platform data with a platform device from one place in the kernel: the i801 i2c bus driver. Let's just associate the GPIO descriptor table with the actual device like everyone else and dynamically create a descriptor table passed along with the GPIO i2c mux. This enables simplification of the GPIO i2c mux driver to use only the descriptor API and the OF probe path gets simplified in the process. The i801 driver was registering the GPIO i2c mux with PLATFORM_DEVID_AUTO which would make it hard to predict the device name and assign the descriptor table properly, but this seems to be a mistake to begin with: all of the GPIO mux devices are hardcoded to look up GPIO lines from the "gpio_ich" GPIO chip. If there are more than one mux, there is certainly more than one gpio chip as well, and then we have more serious problems. Switch to PLATFORM_DEVID_NONE instead. There can be only one. Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Peter Rosin <peda@axentia.se> Cc: Jean Delvare <jdelvare@suse.com> Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> [Removed a newline, suggested by Andy. /Peter] Signed-off-by: Peter Rosin <peda@axentia.se>
Diffstat (limited to 'drivers/i2c/muxes')
-rw-r--r--drivers/i2c/muxes/i2c-mux-gpio.c116
1 files changed, 30 insertions, 86 deletions
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;