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

[Jacek Anaszewski <j.anaszewski@samsung.com>]

On 07/11/2016 01:39 PM, Tony wrote:
>
>
> On 11/07/16 12:25, Jacek Anaszewski wrote:
>> On 07/11/2016 12:48 PM, Tony Makkiel wrote:
>>> The chip can drive 2 sets of RGB leds. Controller can
>>> be controlled via PWM, I2C and audio synchronisation.
>>> This driver uses I2C to communicate with the chip.
>>>
>>> Datasheet: http://www.ti.com/lit/gpn/lp3952
>>>
>>> Signed-off-by: Tony Makkiel <tony.makkiel@daqri.com>
>>> ---
>>>
>>> Changes from v9:
>>>   - Add dependancy on GPIOLIB.
>>>   - make on/off variable of lp3952_on_off function bool.
>>>
>>> Changes from v8:
>>>   - Removed macro LP3952_ACPI_NAME.
>>>   - Replaced acpi_dev_get_property with device_property_read_string
>>>   - Skip led class registration if led data couldn't be read from
>>>     ACPI table.
>>>
>>>
>>>   drivers/leds/Kconfig        |  14 ++
>>>   drivers/leds/Makefile       |   1 +
>>>   drivers/leds/leds-lp3952.c  | 306
>>> ++++++++++++++++++++++++++++++++++++++++++++
>>>   include/linux/leds-lp3952.h | 125 ++++++++++++++++++
>>>   4 files changed, 446 insertions(+)
>>>   create mode 100644 drivers/leds/leds-lp3952.c
>>>   create mode 100644 include/linux/leds-lp3952.h
>>>
>>> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
>>> index 5ae2834..9dcc9b1 100644
>>> --- a/drivers/leds/Kconfig
>>> +++ b/drivers/leds/Kconfig
>>> @@ -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.

>>> +}
>>> +
>>> +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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-- 
Best regards,
Jacek Anaszewski