Re: [PATCH 1/3] leds: lm3532: Fix brightness control for i2c mode

From: Jacek Anaszewski
Date: Thu Aug 01 2019 - 14:52:21 EST


Hi Dan,

Thank you for the patch set. Please find my comments
in the code below.

On 8/1/19 5:14 PM, Dan Murphy wrote:
> Fix the brightness control for I2C mode. Instead of
> changing the full scale current register update the ALS target
> register for the appropriate banks.
>
> In addition clean up some code errors and random misspellings found
> during coding.
>
> Tested on Droid4 as well as LM3532 EVM connected to a BeagleBoneBlack
>
> Fixes: e37a7f8d77e1 ("leds: lm3532: Introduce the lm3532 LED driver")
> Reported-by: Pavel Machek <pavel@xxxxxx>
> Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
> ---
> drivers/leds/leds-lm3532.c | 78 ++++++++++++++++++++++++--------------
> 1 file changed, 50 insertions(+), 28 deletions(-)
>
> diff --git a/drivers/leds/leds-lm3532.c b/drivers/leds/leds-lm3532.c
> index 646100724971..ff197adb2f22 100644
> --- a/drivers/leds/leds-lm3532.c
> +++ b/drivers/leds/leds-lm3532.c
> @@ -23,11 +23,11 @@
> #define LM3532_REG_PWM_B_CFG 0x14
> #define LM3532_REG_PWM_C_CFG 0x15
> #define LM3532_REG_ZONE_CFG_A 0x16
> -#define LM3532_REG_CTRL_A_BRT 0x17
> +#define LM3532_REG_CTRL_A_FS_CURR 0x17
> #define LM3532_REG_ZONE_CFG_B 0x18
> -#define LM3532_REG_CTRL_B_BRT 0x19
> +#define LM3532_REG_CTRL_B_FS_CURR 0x19
> #define LM3532_REG_ZONE_CFG_C 0x1a
> -#define LM3532_REG_CTRL_C_BRT 0x1b
> +#define LM3532_REG_CTRL_C_FS_CURR 0x1b
> #define LM3532_REG_ENABLE 0x1d
> #define LM3532_ALS_CONFIG 0x23
> #define LM3532_REG_ZN_0_HI 0x60
> @@ -38,9 +38,12 @@
> #define LM3532_REG_ZN_2_LO 0x65
> #define LM3532_REG_ZN_3_HI 0x66
> #define LM3532_REG_ZN_3_LO 0x67
> +#define LM3532_REG_ZONE_TRGT_A 0x70
> +#define LM3532_REG_ZONE_TRGT_B 0x75
> +#define LM3532_REG_ZONE_TRGT_C 0x7a
> #define LM3532_REG_MAX 0x7e
>
> -/* Contorl Enable */
> +/* Control Enable */
> #define LM3532_CTRL_A_ENABLE BIT(0)
> #define LM3532_CTRL_B_ENABLE BIT(1)
> #define LM3532_CTRL_C_ENABLE BIT(2)
> @@ -63,6 +66,8 @@
> #define LM3532_ZONE_2 BIT(3)
> #define LM3532_ZONE_3 (BIT(2) | BIT(3))
> #define LM3532_ZONE_4 BIT(4)
> +#define LM3532_BRT_CFG_MASK (LM3532_I2C_CTRL | LM3532_LINEAR_MAP | \
> + LM3532_ZONE_MASK)
>
> #define LM3532_ENABLE_ALS BIT(3)
> #define LM3532_ALS_SEL_SHIFT 6
> @@ -127,6 +132,7 @@ struct lm3532_led {
> int control_bank;
> int mode;
> int num_leds;
> + int ctrl_brt_pointer;
> u32 led_strings[LM3532_MAX_CONTROL_BANKS];
> char label[LED_MAX_NAME_SIZE];
> };
> @@ -161,18 +167,18 @@ struct lm3532_data {
> };
>
> static const struct reg_default lm3532_reg_defs[] = {
> - {LM3532_REG_OUTPUT_CFG, 0xe4},
> + {LM3532_REG_OUTPUT_CFG, 0x24},
> {LM3532_REG_STARTSHUT_RAMP, 0xc0},
> {LM3532_REG_RT_RAMP, 0xc0},
> {LM3532_REG_PWM_A_CFG, 0x82},
> {LM3532_REG_PWM_B_CFG, 0x82},
> {LM3532_REG_PWM_C_CFG, 0x82},
> {LM3532_REG_ZONE_CFG_A, 0xf1},
> - {LM3532_REG_CTRL_A_BRT, 0xf3},
> + {LM3532_REG_CTRL_A_FS_CURR, 0x13},
> {LM3532_REG_ZONE_CFG_B, 0xf1},
> - {LM3532_REG_CTRL_B_BRT, 0xf3},
> + {LM3532_REG_CTRL_B_FS_CURR, 0x13},
> {LM3532_REG_ZONE_CFG_C, 0xf1},
> - {LM3532_REG_CTRL_C_BRT, 0xf3},
> + {LM3532_REG_CTRL_C_FS_CURR, 0x13},
> {LM3532_REG_ENABLE, 0xf8},
> {LM3532_ALS_CONFIG, 0x44},
> {LM3532_REG_ZN_0_HI, 0x35},
> @@ -302,7 +308,7 @@ static int lm3532_led_disable(struct lm3532_led *led_data)
> int ret;
>
> ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
> - ctrl_en_val, ~ctrl_en_val);
> + ctrl_en_val, 0);
> if (ret) {
> dev_err(led_data->priv->dev, "Failed to set ctrl:%d\n", ret);
> return ret;
> @@ -321,7 +327,7 @@ static int lm3532_brightness_set(struct led_classdev *led_cdev,
>
> mutex_lock(&led->priv->lock);
>
> - if (led->mode == LM3532_BL_MODE_ALS) {
> + if (led->mode == LM3532_ALS_CTRL) {
> if (brt_val > LED_OFF)
> ret = lm3532_led_enable(led);
> else
> @@ -339,11 +345,9 @@ static int lm3532_brightness_set(struct led_classdev *led_cdev,
> if (ret)
> goto unlock;
>
> - brightness_reg = LM3532_REG_CTRL_A_BRT + led->control_bank * 2;
> - brt_val = brt_val / LM3532_BRT_VAL_ADJUST;
> -
> + brightness_reg = LM3532_REG_ZONE_TRGT_A + led->control_bank * 5 +
> + (led->ctrl_brt_pointer >> 2);
> ret = regmap_write(led->priv->regmap, brightness_reg, brt_val);
> -
> unlock:
> mutex_unlock(&led->priv->lock);
> return ret;
> @@ -356,8 +360,29 @@ static int lm3532_init_registers(struct lm3532_led *led)
> unsigned int output_cfg_val = 0;
> unsigned int output_cfg_shift = 0;
> unsigned int output_cfg_mask = 0;
> + int brightness_config_reg;
> + int brightness_config_val;
> int ret, i;
>
> + if (drvdata->enable_gpio)
> + gpiod_direction_output(drvdata->enable_gpio, 1);
> +
> + brightness_config_reg = LM3532_REG_ZONE_CFG_A + led->control_bank * 2;
> + /* This could be hard coded to the default value but the control

Coding style issue:

/*
* This is the preferred style for multi-line comments


> + * brightness register may have changed during boot.
> + */> + ret = regmap_read(drvdata->regmap, brightness_config_reg,
> + &led->ctrl_brt_pointer);
> + if (ret)
> + return ret;
> +
> + led->ctrl_brt_pointer &= LM3532_ZONE_MASK;

Could you shed more light on this hardware peculiarity?
What kind of pointer is it?

> + brightness_config_val = led->ctrl_brt_pointer | led->mode;
> + ret = regmap_write(drvdata->regmap, brightness_config_reg,
> + brightness_config_val);
> + if (ret)
> + return ret;
> +
> for (i = 0; i < led->num_leds; i++) {
> output_cfg_shift = led->led_strings[i] * 2;
> output_cfg_val |= (led->control_bank << output_cfg_shift);
> @@ -382,7 +407,6 @@ static int lm3532_als_configure(struct lm3532_data *priv,
> struct lm3532_als_data *als = priv->als_data;
> u32 als_vmin, als_vmax, als_vstep;
> int zone_reg = LM3532_REG_ZN_0_HI;
> - int brightnes_config_reg;
> int ret;
> int i;
>
> @@ -411,14 +435,7 @@ static int lm3532_als_configure(struct lm3532_data *priv,
> als->config = (als->als_avrg_time | (LM3532_ENABLE_ALS) |
> (als->als_input_mode << LM3532_ALS_SEL_SHIFT));
>
> - ret = regmap_write(priv->regmap, LM3532_ALS_CONFIG, als->config);
> - if (ret)
> - return ret;
> -
> - brightnes_config_reg = LM3532_REG_ZONE_CFG_A + led->control_bank * 2;
> -
> - return regmap_update_bits(priv->regmap, brightnes_config_reg,
> - LM3532_I2C_CTRL, LM3532_ALS_CTRL);
> + return regmap_write(priv->regmap, LM3532_ALS_CONFIG, als->config);
> }
>
> static int lm3532_parse_als(struct lm3532_data *priv)
> @@ -542,12 +559,14 @@ static int lm3532_parse_node(struct lm3532_data *priv)
> }
>
> if (led->mode == LM3532_BL_MODE_ALS) {
> + led->mode = LM3532_ALS_CTRL;
> ret = lm3532_parse_als(priv);
> if (ret)
> dev_err(&priv->client->dev, "Failed to parse als\n");
> else
> lm3532_als_configure(priv, led);
> - }
> + } else
> + led->mode = LM3532_I2C_CTRL;

Coding style issue: you need curly braces around the body of "else"
in this case as well.

>
> led->num_leds = fwnode_property_count_u32(child, "led-sources");
> if (led->num_leds > LM3532_MAX_LED_STRINGS) {
> @@ -587,7 +606,13 @@ static int lm3532_parse_node(struct lm3532_data *priv)
> goto child_out;
> }
>
> - lm3532_init_registers(led);
> + ret = lm3532_init_registers(led);
> + if (ret) {
> + dev_err(&priv->client->dev, "register init err: %d\n",
> + ret);
> + fwnode_handle_put(child);
> + goto child_out;
> + }
>
> i++;
> }
> @@ -634,9 +659,6 @@ static int lm3532_probe(struct i2c_client *client,
> return ret;
> }
>
> - if (drvdata->enable_gpio)
> - gpiod_direction_output(drvdata->enable_gpio, 1);
> -
> return ret;
> }
>
>

--
Best regards,
Jacek Anaszewski