[PATCH V5 6/8] backlight: qcom-wled: Add support for WLED4 peripheral

[Kiran Gunda <kgunda@codeaurora.org>]

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>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.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

Changes from V4:
    - replaced the WLED4 macro with 4.

 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 a746bec..49fdd23 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;
@@ -275,6 +321,120 @@ 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 + 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,
 };
@@ -284,6 +444,15 @@ 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,
 };
@@ -293,6 +462,15 @@ 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;
@@ -303,6 +481,11 @@ 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));
@@ -317,10 +500,24 @@ 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)
@@ -369,6 +566,34 @@ 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, },
@@ -382,10 +607,6 @@ 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 = dev->of_node->name;
-
 	switch (version) {
 	case 3:
 		u32_opts = wled3_opts;
@@ -393,6 +614,22 @@ 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:
@@ -400,6 +637,10 @@ static int wled_configure(struct wled *wled, int version)
 		break;
 	}
 
+	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) {
@@ -491,6 +732,14 @@ 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;
@@ -511,6 +760,8 @@ 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