Re: [PATCH v10 1/1] leds: LED driver for TI LP3952 6-Channel Color LED

[Tony <tony.makkiel@daqri.com>]

Thank you for the comments Jacek.

On 11/07/16 13:08, Jacek Anaszewski wrote:

>>>> @@ -228,6 +228,20 @@ config LEDS_LP3944
>>>>         To compile this driver as a module, choose M here: the
>>>>         module will be called leds-lp3944.
>>>>
>>>> +config LEDS_LP3952
>>>> +    tristate "LED Support for TI LP3952 2 channel LED driver"
>>>> +    depends on LEDS_CLASS
>>>> +    depends on I2C
>>>> +    depends on ACPI
>>>> +    depends on GPIOLIB
>>>
>>> Any specific reason for choosing "depends" instead of "select"?
>>
>> select causes "recursive dependency error".
>>
>>
>> drivers/gpio/Kconfig:34:error: recursive dependency detected!
>> For a resolution refer to Documentation/kbuild/kconfig-language.txt
>> subsection "Kconfig recursive dependency limitations"
>> drivers/gpio/Kconfig:34:    symbol GPIOLIB is selected by LEDS_LP3952
>> For a resolution refer to Documentation/kbuild/kconfig-language.txt
>> subsection "Kconfig recursive dependency limitations"
>> drivers/leds/Kconfig:231:    symbol LEDS_LP3952 depends on NEW_LEDS
>> For a resolution refer to Documentation/kbuild/kconfig-language.txt
>> subsection "Kconfig recursive dependency limitations"
>> drivers/leds/Kconfig:8:    symbol NEW_LEDS is selected by
>> BCMA_DRIVER_GPIO
>> For a resolution refer to Documentation/kbuild/kconfig-language.txt
>> subsection "Kconfig recursive dependency limitations"
>> drivers/bcma/Kconfig:97:    symbol BCMA_DRIVER_GPIO depends on GPIOLIB
>
> I didn't get this with my configuration, but it seems that it is
> likely to happen. Let's abide by "depends on" then.
>
> Besides, some redundant brackets are left, see below.
>
>>>
>>>> +    select REGMAP_I2C
>>>> +    help
>>>> +      This option enables support for LEDs connected to the Texas
>>>> +      Instruments LP3952 LED driver.
>>>> +
>>>> +      To compile this driver as a module, choose M here: the
>>>> +      module will be called leds-lp3952.
>>>> +
>>>>   config LEDS_LP55XX_COMMON
>>>>       tristate "Common Driver for TI/National
>>>> LP5521/5523/55231/5562/8501"
>>>>       depends on LEDS_LP5521 || LEDS_LP5523 || LEDS_LP5562 ||
>>>> LEDS_LP8501
>>>> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
>>>> index cb2013d..0684c86 100644
>>>> --- a/drivers/leds/Makefile
>>>> +++ b/drivers/leds/Makefile
>>>> @@ -26,6 +26,7 @@ obj-$(CONFIG_LEDS_PCA9532)        += leds-pca9532.o
>>>>   obj-$(CONFIG_LEDS_GPIO_REGISTER)    += leds-gpio-register.o
>>>>   obj-$(CONFIG_LEDS_GPIO)            += leds-gpio.o
>>>>   obj-$(CONFIG_LEDS_LP3944)        += leds-lp3944.o
>>>> +obj-$(CONFIG_LEDS_LP3952)        += leds-lp3952.o
>>>>   obj-$(CONFIG_LEDS_LP55XX_COMMON)    += leds-lp55xx-common.o
>>>>   obj-$(CONFIG_LEDS_LP5521)        += leds-lp5521.o
>>>>   obj-$(CONFIG_LEDS_LP5523)        += leds-lp5523.o
>>>> diff --git a/drivers/leds/leds-lp3952.c b/drivers/leds/leds-lp3952.c
>>>> new file mode 100644
>>>> index 0000000..c0eb2f4
>>>> --- /dev/null
>>>> +++ b/drivers/leds/leds-lp3952.c
>>>> @@ -0,0 +1,306 @@
>>>> +/*
>>>> + *    LED driver for TI lp3952 controller
>>>> + *
>>>> + *    Copyright (C) 2016, DAQRI, LLC.
>>>> + *    Author: Tony Makkiel <tony.makkiel@daqri.com>
>>>> + *
>>>> + * This program is free software; you can redistribute it and/or
>>>> modify
>>>> + * it under the terms of the GNU General Public License version 2 as
>>>> + * published by the Free Software Foundation.
>>>> + *
>>>> + */
>>>> +
>>>> +#include <linux/acpi.h>
>>>> +#include <linux/delay.h>
>>>> +#include <linux/gpio.h>
>>>> +#include <linux/i2c.h>
>>>> +#include <linux/io.h>
>>>> +#include <linux/kernel.h>
>>>> +#include <linux/leds.h>
>>>> +#include <linux/leds-lp3952.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/notifier.h>
>>>> +#include <linux/platform_device.h>
>>>> +#include <linux/pm.h>
>>>> +#include <linux/reboot.h>
>>>> +#include <linux/regmap.h>
>>>> +
>>>> +static int lp3952_register_write(struct i2c_client *client, u8 reg,
>>>> u8 val)
>>>> +{
>>>> +    int ret;
>>>> +    struct lp3952_led_array *priv = i2c_get_clientdata(client);
>>>> +
>>>> +    ret = regmap_write(priv->regmap, reg, val);
>>>> +
>>>> +    if (ret)
>>>> +        dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
>>>> +            __func__, reg, val, ret);
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static void lp3952_on_off(struct lp3952_led_array *priv,
>>>> +              enum lp3952_leds led_id, bool on)
>>>> +{
>>>> +    int ret, val;
>>>> +
>>>> +    dev_dbg(&priv->client->dev, "%s LED %d to %d\n", __func__,
>>>> led_id, on);
>>>> +
>>>> +    val = 1 << led_id;
>>>> +    if (led_id == LP3952_LED_ALL)
>>>> +        val = LP3952_LED_MASK_ALL;
>>>> +
>>>> +    ret = regmap_update_bits(priv->regmap, LP3952_REG_LED_CTRL, val,
>>>> +                 on ? val : 0);
>>>> +    if (ret)
>>>> +        dev_err(&priv->client->dev, "%s, Error %d\n", __func__, ret);
>>>> +}
>>>> +
>>>> +/*
>>>> + * Using Imax to control brightness. There are 4 possible
>>>> + * setting 25, 50, 75 and 100 % of Imax. Possible values are
>>>> + * values 0-4. 0 meaning turn off.
>>>> + */
>>>> +static int lp3952_set_brightness(struct led_classdev *cdev,
>>>> +                 enum led_brightness value)
>>>> +{
>>>> +    unsigned int reg, shift_val;
>>>> +    struct lp3952_ctrl_hdl *led = container_of(cdev,
>>>> +                           struct lp3952_ctrl_hdl,
>>>> +                           cdev);
>>>> +    struct lp3952_led_array *priv = (struct lp3952_led_array
>>>> *)led->priv;
>>>> +
>>>> +    dev_dbg(cdev->dev, "Brightness request: %d on %d\n", value,
>>>> +        led->channel);
>>>> +
>>>> +    if (value == LED_OFF) {
>>>> +        lp3952_on_off(priv, led->channel, false);
>>>> +        return 0;
>>>> +    }
>>>> +
>>>> +    if (led->channel > LP3952_RED_1) {
>>>> +        dev_err(cdev->dev, " %s Invalid LED requested", __func__);
>>>> +        return -EINVAL;
>>>> +    }
>>>> +
>>>> +    if (led->channel >= LP3952_BLUE_1) {
>>>> +        reg = LP3952_REG_RGB1_MAX_I_CTRL;
>>>> +        shift_val = (led->channel - LP3952_BLUE_1) * 2;
>>>> +    } else {
>>>> +        reg = LP3952_REG_RGB2_MAX_I_CTRL;
>>>> +        shift_val = led->channel * 2;
>>>> +    }
>>>> +
>>>> +    /* Enable the LED in case it is not enabled already */
>>>> +    lp3952_on_off(priv, led->channel, true);
>>>> +
>>>> +    return regmap_update_bits(priv->regmap, reg, 3 << shift_val,
>>>> +                  --value << shift_val);
>>>> +}
>>>> +
>>>> +static int lp3952_get_label(struct device *dev, const char *label,
>>>> char *dest)
>>>> +{
>>>> +    int ret;
>>>> +    const char *str;
>>>> +
>>>> +    ret = device_property_read_string(dev, label, &str);
>>>> +    if (!ret)
>>>> +        strncpy(dest, str, LP3952_LABEL_MAX_LEN);
>>>> +
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int lp3952_register_led_classdev(struct lp3952_led_array *priv)
>>>> +{
>>>> +    int i, acpi_ret, ret = -ENODEV;
>>>> +    static const char *led_name_hdl[LP3952_LED_ALL] = {
>>>> +        "blue2",
>>>> +        "green2",
>>>> +        "red2",
>>>> +        "blue1",
>>>> +        "green1",
>>>> +        "red1"
>>>> +    };
>>>> +
>>>> +    for (i = 0; i < LP3952_LED_ALL; i++) {
>>>> +        acpi_ret = lp3952_get_label(&priv->client->dev,
>>>> led_name_hdl[i],
>>>> +                        priv->leds[i].name);
>>>> +        if (acpi_ret)
>>>> +            continue;
>>>> +
>>>> +        priv->leds[i].cdev.name = priv->leds[i].name;
>>>> +        priv->leds[i].cdev.brightness = LED_OFF;
>>>> +        priv->leds[i].cdev.max_brightness = LP3952_BRIGHT_MAX;
>>>> +        priv->leds[i].cdev.brightness_set_blocking =
>>>> +                lp3952_set_brightness;
>>>> +        priv->leds[i].channel = i;
>>>> +        priv->leds[i].priv = priv;
>>>> +
>>>> +        ret = devm_led_classdev_register(&priv->client->dev,
>>>> +                         &priv->leds[i].cdev);
>>>> +        if (ret < 0) {
>>>> +            dev_err(&priv->client->dev,
>>>> +                "couldn't register LED %s\n",
>>>> +                priv->leds[i].cdev.name);
>>>> +            break;
>>>> +        }
>>>> +    }
>>>> +    return ret;
>>>> +}
>>>> +
>>>> +static int lp3952_set_pattern_gen_cmd(struct lp3952_led_array *priv,
>>>> +                      u8 cmd_index, u8 r, u8 g, u8 b,
>>>> +                      enum lp3952_tt tt, enum lp3952_cet cet)
>>>> +{
>>>> +    int ret;
>>>> +    struct ptrn_gen_cmd line = {
>>>> +        .r = r,
>>>> +        .g = g,
>>>> +        .b = b,
>>>> +        .cet = cet,
>>>> +        .tt = tt
>>>> +    };
>>>> +
>>>> +    if (cmd_index >= LP3952_CMD_REG_COUNT)
>>>> +        return -EINVAL;
>>>> +
>>>> +    ret = lp3952_register_write(priv->client,
>>>> +                    LP3952_REG_CMD_0 + cmd_index * 2,
>>>> +                    line.bytes.msb);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    return (lp3952_register_write(priv->client,
>>>> +                      LP3952_REG_CMD_0 + cmd_index * 2 + 1,
>>>> +                      line.bytes.lsb));
>
> These brackets are redundant.
>
>>>> +}
>>>> +
>>>> +static int lp3952_configure(struct lp3952_led_array *priv)
>>>> +{
>>>> +    int ret;
>>>> +
>>>> +    /* Disable any LEDs on from any previous conf. */
>>>> +    ret = lp3952_register_write(priv->client, LP3952_REG_LED_CTRL, 0);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    /* enable rgb patter, loop */
>>>> +    ret = lp3952_register_write(priv->client, LP3952_REG_PAT_GEN_CTRL,
>>>> +                    LP3952_PATRN_LOOP | LP3952_PATRN_GEN_EN);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    /* Update Bit 6 (Active mode), Select both Led sets, Bit [1:0] */
>>>> +    ret = lp3952_register_write(priv->client, LP3952_REG_ENABLES,
>>>> +                    LP3952_ACTIVE_MODE | LP3952_INT_B00ST_LDR);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    /* Set Cmd1 for RGB intensity,cmd and transition time */
>>>> +    return (lp3952_set_pattern_gen_cmd(priv, 0, I46, I71, I100, TT0,
>>>> +                       CET197));
>
> Ditto.
>
> If you agree I can remove them and take the patch.

Yes please :). Thank you for your help.
>
>>>> +}
>>>> +
>>>> +static const struct regmap_config lp3952_regmap = {
>>>> +    .reg_bits = 8,
>>>> +    .val_bits = 8,
>>>> +    .max_register = REG_MAX,
>>>> +    .cache_type = REGCACHE_RBTREE,
>>>> +};
>>>> +
>>>> +static int lp3952_probe(struct i2c_client *client,
>>>> +            const struct i2c_device_id *id)
>>>> +{
>>>> +    int status;
>>>> +    struct lp3952_ctrl_hdl *leds;
>>>> +    struct lp3952_led_array *priv;
>>>> +
>>>> +    priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
>>>> +    if (!priv)
>>>> +        return -ENOMEM;
>>>> +
>>>> +    leds = devm_kcalloc(&client->dev, LP3952_LED_ALL, sizeof(*leds),
>>>> +                GFP_KERNEL);
>>>> +    if (!leds) {
>>>> +        devm_kfree(&client->dev, priv);
>>>> +        return -ENOMEM;
>>>> +    }
>>>> +
>>>> +    priv->leds = leds;
>>>> +    priv->client = client;
>>>> +
>>>> +    priv->enable_gpio = devm_gpiod_get(&client->dev, "nrst",
>>>> +                       GPIOD_OUT_HIGH);
>>>> +    if (IS_ERR(priv->enable_gpio)) {
>>>> +        status = PTR_ERR(priv->enable_gpio);
>>>> +        dev_err(&client->dev, "Failed to enable gpio: %d\n", status);
>>>> +        return status;
>>>> +    }
>>>> +
>>>> +    priv->regmap = devm_regmap_init_i2c(client, &lp3952_regmap);
>>>> +    if (IS_ERR(priv->regmap)) {
>>>> +        int err = PTR_ERR(priv->regmap);
>>>> +
>>>> +        dev_err(&client->dev, "Failed to allocate register map: %d\n",
>>>> +            err);
>>>> +        return err;
>>>> +    }
>>>> +
>>>> +    i2c_set_clientdata(client, priv);
>>>> +
>>>> +    status = lp3952_configure(priv);
>>>> +    if (status) {
>>>> +        dev_err(&client->dev, "Probe failed. Device not found (%d)\n",
>>>> +            status);
>>>> +        return status;
>>>> +    }
>>>> +
>>>> +    status = lp3952_register_led_classdev(priv);
>>>> +    if (status) {
>>>> +        dev_err(&client->dev, "Unable to register led_classdev: %d\n",
>>>> +            status);
>>>> +        return status;
>>>> +    }
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static int lp3952_remove(struct i2c_client *client)
>>>> +{
>>>> +    struct lp3952_led_array *priv;
>>>> +
>>>> +    priv = i2c_get_clientdata(client);
>>>> +    lp3952_on_off(priv, LP3952_LED_ALL, false);
>>>> +    gpiod_set_value(priv->enable_gpio, 0);
>>>> +
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +static const struct i2c_device_id lp3952_id[] = {
>>>> +    {LP3952_NAME, 0},
>>>> +    {}
>>>> +};
>>>> +
>>>> +#ifdef CONFIG_ACPI
>>>> +static const struct acpi_device_id lp3952_acpi_match[] = {
>>>> +    {"TXNW3952", 0},
>>>> +    {}
>>>> +};
>>>> +
>>>> +MODULE_DEVICE_TABLE(acpi, lp3952_acpi_match);
>>>> +#endif
>>>> +
>>>> +static struct i2c_driver lp3952_i2c_driver = {
>>>> +    .driver = {
>>>> +            .name = LP3952_NAME,
>>>> +            .acpi_match_table = ACPI_PTR(lp3952_acpi_match),
>>>> +    },
>>>> +    .probe = lp3952_probe,
>>>> +    .remove = lp3952_remove,
>>>> +    .id_table = lp3952_id,
>>>> +};
>>>> +
>>>> +module_i2c_driver(lp3952_i2c_driver);
>>>> +
>>>> +MODULE_AUTHOR("Tony Makkiel <tony.makkiel@daqri.com>");
>>>> +MODULE_DESCRIPTION("lp3952 I2C LED controller driver");
>>>> +MODULE_LICENSE("GPL v2");
>>>> diff --git a/include/linux/leds-lp3952.h b/include/linux/leds-lp3952.h
>>>> new file mode 100644
>>>> index 0000000..edd5ed6
>>>> --- /dev/null
>>>> +++ b/include/linux/leds-lp3952.h
>>>> @@ -0,0 +1,125 @@
>>>> +/*
>>>> + *    LED driver for TI lp3952 controller
>>>> + *
>>>> + *    Copyright (C) 2016, DAQRI, LLC.
>>>> + *    Author: Tony Makkiel <tony.makkiel@daqri.com>
>>>> + *
>>>> + * This program is free software; you can redistribute it and/or
>>>> modify
>>>> + * it under the terms of the GNU General Public License version 2 as
>>>> + * published by the Free Software Foundation.
>>>> + *
>>>> + */
>>>> +
>>>> +#ifndef LEDS_LP3952_H_
>>>> +#define LEDS_LP3952_H_
>>>> +
>>>> +#define LP3952_NAME                         "lp3952"
>>>> +#define LP3952_CMD_REG_COUNT                8
>>>> +#define LP3952_BRIGHT_MAX                   4
>>>> +#define LP3952_LABEL_MAX_LEN                15
>>>> +
>>>> +#define LP3952_REG_LED_CTRL                 0x00
>>>> +#define LP3952_REG_R1_BLNK_TIME_CTRL        0x01
>>>> +#define LP3952_REG_R1_BLNK_CYCLE_CTRL       0x02
>>>> +#define LP3952_REG_G1_BLNK_TIME_CTRL        0x03
>>>> +#define LP3952_REG_G1_BLNK_CYCLE_CTRL       0x04
>>>> +#define LP3952_REG_B1_BLNK_TIME_CTRL        0x05
>>>> +#define LP3952_REG_B1_BLNK_CYCLE_CTRL       0x06
>>>> +#define LP3952_REG_ENABLES                  0x0B
>>>> +#define LP3952_REG_PAT_GEN_CTRL             0x11
>>>> +#define LP3952_REG_RGB1_MAX_I_CTRL          0x12
>>>> +#define LP3952_REG_RGB2_MAX_I_CTRL          0x13
>>>> +#define LP3952_REG_CMD_0                    0x50
>>>> +#define LP3952_REG_RESET                    0x60
>>>> +#define REG_MAX                             LP3952_REG_RESET
>>>> +
>>>> +#define LP3952_PATRN_LOOP                   BIT(1)
>>>> +#define LP3952_PATRN_GEN_EN                 BIT(2)
>>>> +#define LP3952_INT_B00ST_LDR                BIT(2)
>>>> +#define LP3952_ACTIVE_MODE                  BIT(6)
>>>> +#define LP3952_LED_MASK_ALL                 0x3f
>>>> +
>>>> +/* Transition Time in ms */
>>>> +enum lp3952_tt {
>>>> +    TT0,
>>>> +    TT55,
>>>> +    TT110,
>>>> +    TT221,
>>>> +    TT422,
>>>> +    TT885,
>>>> +    TT1770,
>>>> +    TT3539
>>>> +};
>>>> +
>>>> +/* Command Execution Time in ms */
>>>> +enum lp3952_cet {
>>>> +    CET197,
>>>> +    CET393,
>>>> +    CET590,
>>>> +    CET786,
>>>> +    CET1180,
>>>> +    CET1376,
>>>> +    CET1573,
>>>> +    CET1769,
>>>> +    CET1966,
>>>> +    CET2163,
>>>> +    CET2359,
>>>> +    CET2556,
>>>> +    CET2763,
>>>> +    CET2949,
>>>> +    CET3146
>>>> +};
>>>> +
>>>> +/* Max Current in % */
>>>> +enum lp3952_colour_I_log_0 {
>>>> +    I0,
>>>> +    I7,
>>>> +    I14,
>>>> +    I21,
>>>> +    I32,
>>>> +    I46,
>>>> +    I71,
>>>> +    I100
>>>> +};
>>>> +
>>>> +enum lp3952_leds {
>>>> +    LP3952_BLUE_2,
>>>> +    LP3952_GREEN_2,
>>>> +    LP3952_RED_2,
>>>> +    LP3952_BLUE_1,
>>>> +    LP3952_GREEN_1,
>>>> +    LP3952_RED_1,
>>>> +    LP3952_LED_ALL
>>>> +};
>>>> +
>>>> +struct lp3952_ctrl_hdl {
>>>> +    struct led_classdev cdev;
>>>> +    char name[LP3952_LABEL_MAX_LEN];
>>>> +    enum lp3952_leds channel;
>>>> +    void *priv;
>>>> +};
>>>> +
>>>> +struct ptrn_gen_cmd {
>>>> +    union {
>>>> +        struct {
>>>> +            u16 tt:3;
>>>> +            u16 b:3;
>>>> +            u16 cet:4;
>>>> +            u16 g:3;
>>>> +            u16 r:3;
>>>> +        };
>>>> +        struct {
>>>> +            u8 lsb;
>>>> +            u8 msb;
>>>> +        } bytes;
>>>> +    };
>>>> +} __packed;
>>>> +
>>>> +struct lp3952_led_array {
>>>> +    struct regmap *regmap;
>>>> +    struct i2c_client *client;
>>>> +    struct gpio_desc *enable_gpio;
>>>> +    struct lp3952_ctrl_hdl *leds;
>>>> +};
>>>> +
>>>> +#endif /* LEDS_LP3952_H_ */
>>>>
>>>
>>>
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>
>