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Date: Thu, 1 Aug 2019 14:17:14 -0500
From: Dan Murphy <dmurphy@...com>
To: Jacek Anaszewski <jacek.anaszewski@...il.com>, <pavel@....cz>,
<tony@...mide.com>, <sre@...nel.org>, <nekit1000@...il.com>,
<mpartap@....net>, <merlijn@...zup.org>
CC: <linux-leds@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/3] leds: lm3532: Fix brightness control for i2c mode
Jacek
On 8/1/19 1:52 PM, Jacek Anaszewski wrote:
> 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@....cz>
>> Signed-off-by: Dan Murphy <dmurphy@...com>
>> ---
>> 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
OK checkpatch did not crib about it but I can change it.
>
>> + * 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?
The bits in the register are called Control A,B or C Brightness Pointer
in the data sheet.
Basically BITS(4:2) control or points to which Zone target register will
be used to control
the output current for the particular control bank
000 = Control A Zone Target 0
001 = Control A Zone Target 1
010 = Control A Zone Target 2
011 = Control A Zone Target 3
1XX = Control A Zone Target 4 (default)
I was trying to keep the variable and register bits name some what the same.
>
>> + 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.
No checkpatch complaint I will fix it.
Dan
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