On 08/06/2017 11:42 PM, Jacek Anaszewski wrote:
> Hi Cedric,
>
> On 08/01/2017 02:09 PM, Cédric Le Goater wrote:
>> The PCA955x family of chips are I2C LED blinkers whose pins not used
>> to control LEDs can be used as general purpose I/Os (GPIOs).
>>
>> The following adds such a support by defining different operation
>> modes for the pins (See bindings documentation for more details). The
>> pca955x driver is then extended with a gpio_chip when some of pins are
>> operating as GPIOs. The default operating mode is to behave as a LED.
>>
>> The GPIO support is conditioned by CONFIG_LEDS_PCA955X_GPIO.
>>
>> Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
>> ---
>> drivers/leds/Kconfig | 11 +++
>> drivers/leds/leds-pca955x.c | 158 +++++++++++++++++++++++++++-----
>> include/dt-bindings/leds/leds-pca955x.h | 16 ++++
>> 3 files changed, 162 insertions(+), 23 deletions(-)
>> create mode 100644 include/dt-bindings/leds/leds-pca955x.h
>>
>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>> index 594b24d410c3..3013cd35c65e 100644
>> --- a/drivers/leds/Kconfig
>> +++ b/drivers/leds/Kconfig
>> @@ -377,6 +377,17 @@ config LEDS_PCA955X
>> LED driver chips accessed via the I2C bus. Supported
>> devices include PCA9550, PCA9551, PCA9552, and PCA9553.
>>
>> +config LEDS_PCA955X_GPIO
>> + bool "Enable GPIO support for PCA955X"
>> + depends on LEDS_PCA955X
>> + depends on GPIOLIB
>> + help
>> + Allow unused pins on PCA955X to be used as gpio.
>> +
>> + To use a pin as gpio the pin type should be set to
>> + PCA955X_TYPE_GPIO in the device tree.
>> +
>> +
>> config LEDS_PCA963X
>> tristate "LED support for PCA963x I2C chip"
>> depends on LEDS_CLASS
>> diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
>> index a8918ff0a7e9..ac0f726ff1af 100644
>> --- a/drivers/leds/leds-pca955x.c
>> +++ b/drivers/leds/leds-pca955x.c
>> @@ -53,6 +53,8 @@
>> #include <linux/slab.h>
>> #include <linux/string.h>
>>
>> +#include <dt-bindings/leds/leds-pca955x.h>
>> +
>> /* LED select registers determine the source that drives LED outputs */
>> #define PCA955X_LS_LED_ON 0x0 /* Output LOW */
>> #define PCA955X_LS_LED_OFF 0x1 /* Output HI-Z */
>> @@ -118,6 +120,9 @@ struct pca955x {
>> struct pca955x_led *leds;
>> struct pca955x_chipdef *chipdef;
>> struct i2c_client *client;
>> +#ifdef CONFIG_LEDS_PCA955X_GPIO
>> + struct gpio_chip gpio;
>> +#endif
>> };
>>
>> struct pca955x_led {
>> @@ -125,6 +130,7 @@ struct pca955x_led {
>> struct led_classdev led_cdev;
>> int led_num; /* 0 .. 15 potentially */
>> char name[32];
>> + u32 type;
>> const char *default_trigger;
>> };
>>
>> @@ -259,6 +265,65 @@ static int pca955x_led_set(struct led_classdev *led_cdev,
>> return 0;
>> }
>>
>> +#ifdef CONFIG_LEDS_PCA955X_GPIO
>> +/*
>> + * Read the INPUT register, which contains the state of LEDs.
>> + */
>> +static u8 pca955x_read_input(struct i2c_client *client, int n)
>> +{
>> + return (u8)i2c_smbus_read_byte_data(client, n);
>> +}
>> +
>> +static int pca955x_gpio_request_pin(struct gpio_chip *gc, unsigned int offset)
>> +{
>> + struct pca955x *pca955x = gpiochip_get_data(gc);
>> + struct pca955x_led *led = &pca955x->leds[offset];
>> +
>> + if (led->type == PCA955X_TYPE_GPIO)
>> + return 0;
>> +
>> + return -EBUSY;
>> +}
>> +
>> +static void pca955x_gpio_set_value(struct gpio_chip *gc, unsigned int offset,
>> + int val)
>> +{
>> + struct pca955x *pca955x = gpiochip_get_data(gc);
>> + struct pca955x_led *led = &pca955x->leds[offset];
>> +
>> + if (val)
>> + pca955x_led_set(&led->led_cdev, LED_FULL);
>> + else
>> + pca955x_led_set(&led->led_cdev, LED_OFF);
>> +}
>> +
>> +static int pca955x_gpio_get_value(struct gpio_chip *gc, unsigned int offset)
>> +{
>> + struct pca955x *pca955x = gpiochip_get_data(gc);
>> + struct pca955x_led *led = &pca955x->leds[offset];
>> + u8 reg = pca955x_read_input(pca955x->client, led->led_num / 8);
>> +
>> + return !!(reg & (1 << (led->led_num % 8)));
>> +}
>> +
>> +static int pca955x_gpio_direction_input(struct gpio_chip *gc,
>> + unsigned int offset)
>> +{
>> + /* To use as input ensure pin is not driven */
>> + pca955x_gpio_set_value(gc, offset, 0);
>> +
>> + return 0;
>> +}
>> +
>> +static int pca955x_gpio_direction_output(struct gpio_chip *gc,
>> + unsigned int offset, int val)
>> +{
>> + pca955x_gpio_set_value(gc, offset, val);
>> +
>> + return 0;
>> +}
>> +#endif /* CONFIG_LEDS_PCA955X_GPIO */
>> +
>> #if IS_ENABLED(CONFIG_OF)
>> static struct pca955x_platform_data *
>> pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
>> @@ -297,6 +362,8 @@ pca955x_pdata_of_init(struct i2c_client *client, struct pca955x_chipdef *chip)
>> snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
>> "%s", name);
>>
>> + pdata->leds[reg].type = PCA955X_TYPE_LED;
>> + of_property_read_u32(child, "type", &pdata->leds[reg].type);
>> of_property_read_string(child, "linux,default-trigger",
>> &pdata->leds[reg].default_trigger);
>> }
>> @@ -332,6 +399,7 @@ static int pca955x_probe(struct i2c_client *client,
>> struct i2c_adapter *adapter;
>> int i, err;
>> struct pca955x_platform_data *pdata;
>> + int ngpios = 0;
>>
>> if (id) {
>> chip = &pca955x_chipdefs[id->driver_data];
>> @@ -391,36 +459,52 @@ static int pca955x_probe(struct i2c_client *client,
>> pca955x->chipdef = chip;
>>
>> for (i = 0; i < chip->bits; i++) {
>> + struct pca955x_led *pdata_led = &pdata->leds[i];
>> +
>> pca955x_led = &pca955x->leds[i];
>> pca955x_led->led_num = i;
>> pca955x_led->pca955x = pca955x;
>> -
>> - /* Platform data can specify LED names and default triggers */
>> - if (pdata) {
>> - if (pdata->leds[i].name)
>> + pca955x_led->type = pdata_led->type;
>> +
>> + switch (pca955x_led->type) {
>> + case PCA955X_TYPE_NONE:
>> + break;
>> + case PCA955X_TYPE_GPIO:
>> + ngpios++;
>> + break;
>> + case PCA955X_TYPE_LED:
>> + /*
>> + * Platform data can specify LED names and
>> + * default triggers
>> + */
>> + if (pdata) {
>
> Similarly as in 1/4: this check seems to be redundant and we could
> simplify the code a bit here.
yes.
>> + if (pdata->leds[i].name)
>> + snprintf(pca955x_led->name,
>> + sizeof(pca955x_led->name),
>> + "pca955x:%s",
>> + pdata->leds[i].name);
>
> DT label property should contain also vendor prefix, and there should be
> no need to concatenate the segments here. The situation when label is
> not provided and LED class device name is taken from DT node name
> should be considered as a fallback.
So, should I start the patchset with a preliminary cleanup removing all
the calls doing snprintf(pdata->leds[reg].name ...) ? This is the case in :
pca955x_pdata_of_init()
Thanks,
C.
>
>> + if (pdata->leds[i].default_trigger)
>> + pca955x_led->led_cdev.default_trigger =
>> + pdata->leds[i].default_trigger;
>> + } else {
>> snprintf(pca955x_led->name,
>> - sizeof(pca955x_led->name), "pca955x:%s",
>> - pdata->leds[i].name);
>> - if (pdata->leds[i].default_trigger)
>> - pca955x_led->led_cdev.default_trigger =
>> - pdata->leds[i].default_trigger;
>> - } else {
>> - snprintf(pca955x_led->name, sizeof(pca955x_led->name),
>> - "pca955x:%d", i);
>> - }
>> + sizeof(pca955x_led->name),
>> + "pca955x:%d", i);
>> + }
>>
>> - pca955x_led->led_cdev.name = pca955x_led->name;
>> - pca955x_led->led_cdev.brightness_set_blocking = pca955x_led_set;
>> + pca955x_led->led_cdev.name = pca955x_led->name;
>> + pca955x_led->led_cdev.brightness_set_blocking =
>> + pca955x_led_set;
>>
>> - err = devm_led_classdev_register(&client->dev,
>> - &pca955x_led->led_cdev);
>> - if (err)
>> - return err;
>> - }
>> + err = devm_led_classdev_register(&client->dev,
>> + &pca955x_led->led_cdev);
>> + if (err)
>> + return err;
>>
>> - /* Turn off LEDs */
>> - for (i = 0; i < pca95xx_num_led_regs(chip->bits); i++)
>> - pca955x_write_ls(client, i, 0x55);
>> + /* Turn off LED */
>> + pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
>> + }
>> + }
>>
>> /* PWM0 is used for half brightness or 50% duty cycle */
>> pca955x_write_pwm(client, 0, 255-LED_HALF);
>> @@ -432,6 +516,34 @@ static int pca955x_probe(struct i2c_client *client,
>> pca955x_write_psc(client, 0, 0);
>> pca955x_write_psc(client, 1, 0);
>>
>> +#ifdef CONFIG_LEDS_PCA955X_GPIO
>> + if (ngpios) {
>> + pca955x->gpio.label = "gpio-pca955x";
>> + pca955x->gpio.direction_input = pca955x_gpio_direction_input;
>> + pca955x->gpio.direction_output = pca955x_gpio_direction_output;
>> + pca955x->gpio.set = pca955x_gpio_set_value;
>> + pca955x->gpio.get = pca955x_gpio_get_value;
>> + pca955x->gpio.request = pca955x_gpio_request_pin;
>> + pca955x->gpio.can_sleep = 1;
>> + pca955x->gpio.base = -1;
>> + pca955x->gpio.ngpio = ngpios;
>> + pca955x->gpio.parent = &client->dev;
>> + pca955x->gpio.owner = THIS_MODULE;
>> +
>> + err = devm_gpiochip_add_data(&client->dev, &pca955x->gpio,
>> + pca955x);
>> + if (err) {
>> + /* Use data->gpio.dev as a flag for freeing gpiochip */
>> + pca955x->gpio.parent = NULL;
>> + dev_warn(&client->dev, "could not add gpiochip\n");
>> + return err;
>> + }
>> + dev_info(&client->dev, "gpios %i...%i\n",
>> + pca955x->gpio.base, pca955x->gpio.base +
>> + pca955x->gpio.ngpio - 1);
>> + }
>> +#endif
>> +
>> return 0;
>> }
>>
>> diff --git a/include/dt-bindings/leds/leds-pca955x.h b/include/dt-bindings/leds/leds-pca955x.h
>> new file mode 100644
>> index 000000000000..78cb7e979de7
>> --- /dev/null
>> +++ b/include/dt-bindings/leds/leds-pca955x.h
>> @@ -0,0 +1,16 @@
>> +/*
>> + * This header provides constants for pca955x LED bindings.
>> + *
>> + * This file is licensed under the terms of the GNU General Public
>> + * License version 2. This program is licensed "as is" without any
>> + * warranty of any kind, whether express or implied.
>> + */
>> +
>> +#ifndef _DT_BINDINGS_LEDS_PCA955X_H
>> +#define _DT_BINDINGS_LEDS_PCA955X_H
>> +
>> +#define PCA955X_TYPE_NONE 0
>> +#define PCA955X_TYPE_LED 1
>> +#define PCA955X_TYPE_GPIO 2
>> +
>> +#endif /* _DT_BINDINGS_LEDS_PCA955X_H */
>>
>
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