Re: [PATCH V4 6/8] backlight: qcom-wled: Add support for WLED4 peripheral

[Daniel Thompson <daniel.thompson@linaro.org>]

On 09/07/18 11:22, Kiran Gunda wrote:
> WLED4 peripheral is present on some PMICs like pmi8998 and
> pm660l. It has a different register map and configurations
> are also different. Add support for it.
> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> ---
> Changes from V3:
> 	- The WLED3 specific changes are splitted out
> 	- Merged the wled3_sync_toggle and wled4_syn_toggle functions
> 	- Modified the compatible .data
> 	- Moved from if/else to switch/case to select the version specific data
> 	- Addressed few more minor comments from Bjorn
> 
>   drivers/video/backlight/qcom-wled.c | 264 +++++++++++++++++++++++++++++++++++-
>   1 file changed, 258 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 87fc1d0..362d254 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -64,6 +64,28 @@
>   #define WLED3_SINK_REG_STR_CABC(n)			(0x66 + (n * 0x10))
>   #define  WLED3_SINK_REG_STR_CABC_MASK			BIT(7)
>   
> +/* WLED4 specific sink registers */
> +#define WLED4_SINK_REG_CURR_SINK			0x46
> +#define  WLED4_SINK_REG_CURR_SINK_MASK			GENMASK(7, 4)
> +#define  WLED4_SINK_REG_CURR_SINK_SHFT			4
> +
> +/* WLED4 specific per-'string' registers below */
> +#define WLED4_SINK_REG_STR_MOD_EN(n)			(0x50 + (n * 0x10))
> +#define  WLED4_SINK_REG_STR_MOD_MASK			BIT(7)
> +
> +#define WLED4_SINK_REG_STR_FULL_SCALE_CURR(n)		(0x52 + (n * 0x10))
> +#define  WLED4_SINK_REG_STR_FULL_SCALE_CURR_MASK	GENMASK(3, 0)
> +
> +#define WLED4_SINK_REG_STR_MOD_SRC(n)			(0x53 + (n * 0x10))
> +#define  WLED4_SINK_REG_STR_MOD_SRC_MASK		BIT(0)
> +#define  WLED4_SINK_REG_STR_MOD_SRC_INT			0x00
> +#define  WLED4_SINK_REG_STR_MOD_SRC_EXT			0x01
> +
> +#define WLED4_SINK_REG_STR_CABC(n)			(0x56 + (n * 0x10))
> +#define  WLED4_SINK_REG_STR_CABC_MASK			BIT(7)
> +
> +#define WLED4_SINK_REG_BRIGHT(n)			(0x57 + (n * 0x10))
> +
>   struct wled_var_cfg {
>   	const u32 *values;
>   	u32 (*fn)(u32);
> @@ -98,6 +120,7 @@ struct wled {
>   	struct device *dev;
>   	struct regmap *regmap;
>   	u16 ctrl_addr;
> +	u16 sink_addr;
>   	u16 max_string_count;
>   	u32 brightness;
>   	u32 max_brightness;
> @@ -124,6 +147,29 @@ static int wled3_set_brightness(struct wled *wled, u16 brightness)
>   	return 0;
>   }
>   
> +static int wled4_set_brightness(struct wled *wled, u16 brightness)
> +{
> +	int rc, i;
> +	u16 low_limit = wled->max_brightness * 4 / 1000;
> +	u8 v[2];
> +
> +	/* WLED4's lower limit of operation is 0.4% */
> +	if (brightness > 0 && brightness < low_limit)
> +		brightness = low_limit;
> +
> +	v[0] = brightness & 0xff;
> +	v[1] = (brightness >> 8) & 0xf;
> +
> +	for (i = 0;  i < wled->cfg.num_strings; ++i) {
> +		rc = regmap_bulk_write(wled->regmap, wled->sink_addr +
> +				       WLED4_SINK_REG_BRIGHT(i), v, 2);
> +		if (rc < 0)
> +			return rc;
> +	}
> +
> +	return 0;
> +}
> +
>   static int wled_module_enable(struct wled *wled, int val)
>   {
>   	int rc;
> @@ -141,13 +187,13 @@ static int wled_sync_toggle(struct wled *wled)
>   	unsigned int mask = GENMASK(wled->max_string_count - 1, 0);
>   
>   	rc = regmap_update_bits(wled->regmap,
> -				wled->ctrl_addr + WLED_SINK_REG_SYNC,
> +				wled->sink_addr + WLED_SINK_REG_SYNC,
>   				mask, mask);
>   	if (rc < 0)
>   		return rc;
>   
>   	rc = regmap_update_bits(wled->regmap,
> -				wled->ctrl_addr + WLED_SINK_REG_SYNC,
> +				wled->sink_addr + WLED_SINK_REG_SYNC,
>   				mask, WLED_SINK_REG_SYNC_CLEAR);
>   
>   	return rc;
> @@ -274,6 +320,120 @@ static int wled3_setup(struct wled *wled)
>   	.cabc = false,
>   };
>   
> +static int wled4_setup(struct wled *wled)
> +{
> +	int rc, temp, i, j;
> +	u16 addr;
> +	u8 sink_en = 0;
> +	u32 sink_cfg = 0;
> +
> +	rc = regmap_update_bits(wled->regmap,
> +				wled->ctrl_addr + WLED_CTRL_REG_OVP,
> +				WLED_CTRL_REG_OVP_MASK, wled->cfg.ovp);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = regmap_update_bits(wled->regmap,
> +				wled->ctrl_addr + WLED_CTRL_REG_ILIMIT,
> +				WLED_CTRL_REG_ILIMIT_MASK,
> +				wled->cfg.boost_i_limit);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = regmap_update_bits(wled->regmap,
> +				wled->ctrl_addr + WLED_CTRL_REG_FREQ,
> +				WLED_CTRL_REG_FREQ_MASK,
> +				wled->cfg.switch_freq);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = regmap_read(wled->regmap, wled->sink_addr +
> +			 WLED4_SINK_REG_CURR_SINK, &sink_cfg);
> +	if (rc < 0)
> +		return rc;
> +
> +	for (i = 0; i < wled->cfg.num_strings; i++) {
> +		j = wled->cfg.enabled_strings[i];
> +		temp = j + WLED4_SINK_REG_CURR_SINK_SHFT;
> +		sink_en |= 1 << temp;
> +	}
> +
> +	if (sink_cfg == sink_en)
> +		return 0;
> +
> +	rc = regmap_update_bits(wled->regmap,
> +				wled->sink_addr + WLED4_SINK_REG_CURR_SINK,
> +				WLED4_SINK_REG_CURR_SINK_MASK, 0);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
> +				WLED_CTRL_REG_MOD_EN,
> +				WLED_CTRL_REG_MOD_EN_MASK, 0);
> +	if (rc < 0)
> +		return rc;
> +
> +	/* Per sink/string configuration */
> +	for (i = 0; i < wled->cfg.num_strings; i++) {
> +		j = wled->cfg.enabled_strings[i];
> +
> +		addr = wled->sink_addr +
> +				WLED4_SINK_REG_STR_MOD_EN(j);
> +		rc = regmap_update_bits(wled->regmap, addr,
> +					WLED4_SINK_REG_STR_MOD_MASK,
> +					WLED4_SINK_REG_STR_MOD_MASK);
> +		if (rc < 0)
> +			return rc;
> +
> +		addr = wled->sink_addr +
> +				WLED4_SINK_REG_STR_FULL_SCALE_CURR(j);
> +		rc = regmap_update_bits(wled->regmap, addr,
> +					WLED4_SINK_REG_STR_FULL_SCALE_CURR_MASK,
> +					wled->cfg.string_i_limit);
> +		if (rc < 0)
> +			return rc;
> +
> +		addr = wled->sink_addr +
> +				WLED4_SINK_REG_STR_CABC(j);
> +		rc = regmap_update_bits(wled->regmap, addr,
> +					WLED4_SINK_REG_STR_CABC_MASK,
> +					wled->cfg.cabc ?
> +					WLED4_SINK_REG_STR_CABC_MASK : 0);
> +		if (rc < 0)
> +			return rc;
> +	}
> +
> +	rc = regmap_update_bits(wled->regmap, wled->ctrl_addr +
> +				WLED_CTRL_REG_MOD_EN,
> +				WLED_CTRL_REG_MOD_EN_MASK,
> +				WLED_CTRL_REG_MOD_EN_MASK);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = regmap_update_bits(wled->regmap,
> +				wled->sink_addr + WLED4_SINK_REG_CURR_SINK,
> +				WLED4_SINK_REG_CURR_SINK_MASK, sink_en);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = wled_sync_toggle(wled);
> +	if (rc < 0) {
> +		dev_err(wled->dev, "Failed to toggle sync reg rc:%d\n", rc);
> +		return rc;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct wled_config wled4_config_defaults = {
> +	.boost_i_limit = 4,
> +	.string_i_limit = 10,
> +	.ovp = 1,
> +	.num_strings = 4,
> +	.switch_freq = 11,
> +	.cabc = false,
> +};
> +
>   static const u32 wled3_boost_i_limit_values[] = {
>   	105, 385, 525, 805, 980, 1260, 1400, 1680,
>   };
> @@ -283,6 +443,15 @@ static int wled3_setup(struct wled *wled)
>   	.size = ARRAY_SIZE(wled3_boost_i_limit_values),
>   };
>   
> +static const u32 wled4_boost_i_limit_values[] = {
> +	105, 280, 450, 620, 970, 1150, 1300, 1500,
> +};
> +
> +static const struct wled_var_cfg wled4_boost_i_limit_cfg = {
> +	.values = wled4_boost_i_limit_values,
> +	.size = ARRAY_SIZE(wled4_boost_i_limit_values),
> +};
> +
>   static const u32 wled3_ovp_values[] = {
>   	35, 32, 29, 27,
>   };
> @@ -292,6 +461,15 @@ static int wled3_setup(struct wled *wled)
>   	.size = ARRAY_SIZE(wled3_ovp_values),
>   };
>   
> +static const u32 wled4_ovp_values[] = {
> +	31100, 29600, 19600, 18100,
> +};
> +
> +static const struct wled_var_cfg wled4_ovp_cfg = {
> +	.values = wled4_ovp_values,
> +	.size = ARRAY_SIZE(wled4_ovp_values),
> +};
> +
>   static u32 wled3_num_strings_values_fn(u32 idx)
>   {
>   	return idx + 1;
> @@ -302,6 +480,11 @@ static u32 wled3_num_strings_values_fn(u32 idx)
>   	.size = 3,
>   };
>   
> +static const struct wled_var_cfg wled4_num_strings_cfg = {
> +	.fn = wled3_num_strings_values_fn,
> +	.size = 4,
> +};
> +
>   static u32 wled3_switch_freq_values_fn(u32 idx)
>   {
>   	return 19200 / (2 * (1 + idx));
> @@ -316,10 +499,24 @@ static u32 wled3_switch_freq_values_fn(u32 idx)
>   	.size = 26,
>   };
>   
> +static const u32 wled4_string_i_limit_values[] = {
> +	0, 2500, 5000, 7500, 10000, 12500, 15000, 17500, 20000,
> +	22500, 25000, 27500, 30000,
> +};
> +
> +static const struct wled_var_cfg wled4_string_i_limit_cfg = {
> +	.values = wled4_string_i_limit_values,
> +	.size = ARRAY_SIZE(wled4_string_i_limit_values),
> +};
> +
>   static const struct wled_var_cfg wled3_string_cfg = {
>   	.size = 8,
>   };
>   
> +static const struct wled_var_cfg wled4_string_cfg = {
> +	.size = 16,
> +};
> +
>   static u32 wled_values(const struct wled_var_cfg *cfg, u32 idx)
>   {
>   	if (idx >= cfg->size)
> @@ -332,6 +529,7 @@ static u32 wled_values(const struct wled_var_cfg *cfg, u32 idx)
>   }
>   
>   #define	WLED3	3
> +#define	WLED4	4

Are these macros always going to define 3 to be 3 and 4 to be 4. If so 
we probably don't need them (and they should be removed from patch 5/8 too).

There is a degree of nitpicking here however. The rest looks OK to me.


Daniel.