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Date:   Thu, 17 Oct 2019 12:06:31 +0100
From:   Daniel Thompson <daniel.thompson@linaro.org>
To:     Kiran Gunda <kgunda@codeaurora.org>
Cc:     bjorn.andersson@linaro.org, jingoohan1@gmail.com,
        lee.jones@linaro.org, b.zolnierkie@samsung.com,
        dri-devel@lists.freedesktop.org, jacek.anaszewski@gmail.com,
        pavel@ucw.cz, robh+dt@kernel.org, mark.rutland@arm.com,
        linux-leds@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, Andy Gross <agross@kernel.org>,
        linux-arm-msm@vger.kernel.org, linux-fbdev@vger.kernel.org
Subject: Re: [PATCH V7 4/6] backlight: qcom-wled: Add support for WLED4
 peripheral.
Message-ID: <20191017110631.k2u254jjcza6ngzt@holly.lan>
References: <1571220826-7740-1-git-send-email-kgunda@codeaurora.org>
 <1571220826-7740-5-git-send-email-kgunda@codeaurora.org>
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On Wed, Oct 16, 2019 at 03:43:44PM +0530, 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.

There is code buried in this patch that looks like it changes the name
that will be handed to the backlight sub-system.

It's purpose needs to be explained in the patch description (or the code
moved to a new patch).


Daniel.

> 
> Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
>  drivers/video/backlight/qcom-wled.c | 263 +++++++++++++++++++++++++++++++++++-
>  1 file changed, 257 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/video/backlight/qcom-wled.c b/drivers/video/backlight/qcom-wled.c
> index 45eeda4..2807b4b 100644
> --- a/drivers/video/backlight/qcom-wled.c
> +++ b/drivers/video/backlight/qcom-wled.c
> @@ -17,7 +17,7 @@
>  
>  #define WLED3_SINK_REG_BRIGHT_MAX			0xFFF
>  
> -/* WLED3 control registers */
> +/* WLED3/WLED4 control registers */
>  #define WLED3_CTRL_REG_MOD_EN				0x46
>  #define  WLED3_CTRL_REG_MOD_EN_MASK			BIT(7)
>  #define  WLED3_CTRL_REG_MOD_EN_SHIFT			7
> @@ -31,7 +31,7 @@
>  #define WLED3_CTRL_REG_ILIMIT				0x4e
>  #define  WLED3_CTRL_REG_ILIMIT_MASK			GENMASK(2, 0)
>  
> -/* WLED3 sink registers */
> +/* WLED3/WLED4 sink registers */
>  #define WLED3_SINK_REG_SYNC				0x47
>  #define  WLED3_SINK_REG_SYNC_CLEAR			0x00
>  
> @@ -56,6 +56,28 @@
>  #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);
> @@ -90,6 +112,7 @@ struct wled {
>  	struct device *dev;
>  	struct regmap *regmap;
>  	u16 ctrl_addr;
> +	u16 sink_addr;
>  	u16 max_string_count;
>  	u32 brightness;
>  	u32 max_brightness;
> @@ -116,6 +139,29 @@ 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;
> @@ -267,6 +313,120 @@ static int wled3_setup(struct wled *wled)
>  	.enabled_strings = {0, 1, 2, 3},
>  };
>  
> +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 + WLED3_CTRL_REG_OVP,
> +				WLED3_CTRL_REG_OVP_MASK, wled->cfg.ovp);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = regmap_update_bits(wled->regmap,
> +				wled->ctrl_addr + WLED3_CTRL_REG_ILIMIT,
> +				WLED3_CTRL_REG_ILIMIT_MASK,
> +				wled->cfg.boost_i_limit);
> +	if (rc < 0)
> +		return rc;
> +
> +	rc = regmap_update_bits(wled->regmap,
> +				wled->ctrl_addr + WLED3_CTRL_REG_FREQ,
> +				WLED3_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 +
> +				WLED3_CTRL_REG_MOD_EN,
> +				WLED3_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 +
> +				WLED3_CTRL_REG_MOD_EN,
> +				WLED3_CTRL_REG_MOD_EN_MASK,
> +				WLED3_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,
>  };
> @@ -276,6 +436,15 @@ 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,
>  };
> @@ -285,6 +454,15 @@ 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;
> @@ -295,6 +473,11 @@ 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));
> @@ -309,10 +492,24 @@ 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)
> @@ -361,6 +558,34 @@ static int wled_configure(struct wled *wled, int version)
>  		},
>  	};
>  
> +	const struct wled_u32_opts wled4_opts[] = {
> +		{
> +			.name = "qcom,current-boost-limit",
> +			.val_ptr = &cfg->boost_i_limit,
> +			.cfg = &wled4_boost_i_limit_cfg,
> +		},
> +		{
> +			.name = "qcom,current-limit-microamp",
> +			.val_ptr = &cfg->string_i_limit,
> +			.cfg = &wled4_string_i_limit_cfg,
> +		},
> +		{
> +			.name = "qcom,ovp-millivolt",
> +			.val_ptr = &cfg->ovp,
> +			.cfg = &wled4_ovp_cfg,
> +		},
> +		{
> +			.name = "qcom,switching-freq",
> +			.val_ptr = &cfg->switch_freq,
> +			.cfg = &wled3_switch_freq_cfg,
> +		},
> +		{
> +			.name = "qcom,num-strings",
> +			.val_ptr = &cfg->num_strings,
> +			.cfg = &wled4_num_strings_cfg,
> +		},
> +	};
> +
>  	const struct wled_bool_opts bool_opts[] = {
>  		{ "qcom,cs-out", &cfg->cs_out_en, },
>  		{ "qcom,ext-gen", &cfg->ext_gen, },
> @@ -374,10 +599,6 @@ static int wled_configure(struct wled *wled, int version)
>  	}
>  	wled->ctrl_addr = be32_to_cpu(*prop_addr);
>  
> -	rc = of_property_read_string(dev->of_node, "label", &wled->name);
> -	if (rc)
> -		wled->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
> -
>  	switch (version) {
>  	case 3:
>  		u32_opts = wled3_opts;
> @@ -385,6 +606,22 @@ static int wled_configure(struct wled *wled, int version)
>  		*cfg = wled3_config_defaults;
>  		wled->wled_set_brightness = wled3_set_brightness;
>  		wled->max_string_count = 3;
> +		wled->sink_addr = wled->ctrl_addr;
> +		break;
> +
> +	case 4:
> +		u32_opts = wled4_opts;
> +		size = ARRAY_SIZE(wled4_opts);
> +		*cfg = wled4_config_defaults;
> +		wled->wled_set_brightness = wled4_set_brightness;
> +		wled->max_string_count = 4;
> +
> +		prop_addr = of_get_address(dev->of_node, 1, NULL, NULL);
> +		if (!prop_addr) {
> +			dev_err(wled->dev, "invalid IO resources\n");
> +			return -EINVAL;
> +		}
> +		wled->sink_addr = be32_to_cpu(*prop_addr);
>  		break;
>  
>  	default:
> @@ -392,6 +629,10 @@ static int wled_configure(struct wled *wled, int version)
>  		return -EINVAL;
>  	}
>  
> +	rc = of_property_read_string(dev->of_node, "label", &wled->name);
> +	if (rc)
> +		wled->name = dev->of_node->name;
> +
>  	for (i = 0; i < size; ++i) {
>  		rc = of_property_read_u32(dev->of_node, u32_opts[i].name, &val);
>  		if (rc == -EINVAL) {
> @@ -483,6 +724,14 @@ static int wled_probe(struct platform_device *pdev)
>  		}
>  		break;
>  
> +	case 4:
> +		rc = wled4_setup(wled);
> +		if (rc) {
> +			dev_err(&pdev->dev, "wled4_setup failed\n");
> +			return rc;
> +		}
> +		break;
> +
>  	default:
>  		dev_err(wled->dev, "Invalid WLED version\n");
>  		break;
> @@ -503,6 +752,8 @@ static int wled_probe(struct platform_device *pdev)
>  
>  static const struct of_device_id wled_match_table[] = {
>  	{ .compatible = "qcom,pm8941-wled", .data = (void *)3 },
> +	{ .compatible = "qcom,pmi8998-wled", .data = (void *)4 },
> +	{ .compatible = "qcom,pm660l-wled", .data = (void *)4 },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, wled_match_table);
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>  a Linux Foundation Collaborative Project
>