[PATCH v10 1/2] dt-bindings: leds: Add Qualcomm Light Pulse Generator binding

[PATCH v10 1/2] dt-bindings: leds: Add Qualcomm Light Pulse Generator binding

[Bjorn Andersson]

This adds the binding document describing the three hardware blocks
related to the Light Pulse Generator found in a wide range of Qualcomm
PMICs.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Changes since v9:
- "led" child of "multi-led" now needed a patternProperties
- use generic "led-controller" and "pwm-controller" in example

 .../bindings/leds/leds-qcom-lpg.yaml          | 173 ++++++++++++++++++
 1 file changed, 173 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml

diff --git a/Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml b/Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml
new file mode 100644
index 000000000000..336bd8e10efd
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml
@@ -0,0 +1,173 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/leds/leds-qcom-lpg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm Light Pulse Generator
+
+maintainers:
+  - Bjorn Andersson <bjorn.andersson@linaro.org>
+
+description: >
+  The Qualcomm Light Pulse Generator consists of three different hardware blocks;
+  a ramp generator with lookup table, the light pulse generator and a three
+  channel current sink. These blocks are found in a wide range of Qualcomm PMICs.
+
+properties:
+  compatible:
+    enum:
+      - qcom,pm8150b-lpg
+      - qcom,pm8150l-lpg
+      - qcom,pm8916-pwm
+      - qcom,pm8941-lpg
+      - qcom,pm8994-lpg
+      - qcom,pmc8180c-lpg
+      - qcom,pmi8994-lpg
+      - qcom,pmi8998-lpg
+
+  "#pwm-cells":
+    const: 2
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 0
+
+  qcom,power-source:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      power-source used to drive the output, as defined in the datasheet.
+      Should be specified if the TRILED block is present
+    enum: [0, 1, 3]
+
+  qcom,dtest:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    description: >
+      A list of integer pairs, where each pair represent the dtest line the
+      particular channel should be connected to and the flags denoting how the
+      value should be outputed, as defined in the datasheet. The number of
+      pairs should be the same as the number of channels.
+    items:
+      items:
+        - description: dtest line to attach
+        - description: flags for the attachment
+
+  multi-led:
+    type: object
+    $ref: leds-class-multicolor.yaml#
+    properties:
+      "#address-cells":
+        const: 1
+
+      "#size-cells":
+        const: 0
+
+    patternProperties:
+      "^led@[0-9a-f]$":
+        type: object
+        $ref: common.yaml#
+
+patternProperties:
+  "^led@[0-9a-f]$":
+    type: object
+    $ref: common.yaml#
+
+    properties:
+      reg: true
+
+    required:
+      - reg
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    led-controller {
+      compatible = "qcom,pmi8994-lpg";
+
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      qcom,power-source = <1>;
+
+      qcom,dtest = <0 0>,
+                   <0 0>,
+                   <0 0>,
+                   <4 1>;
+
+      led@1 {
+        reg = <1>;
+        color = <LED_COLOR_ID_GREEN>;
+        function = LED_FUNCTION_INDICATOR;
+        function-enumerator = <1>;
+      };
+
+      led@2 {
+        reg = <2>;
+        color = <LED_COLOR_ID_GREEN>;
+        function = LED_FUNCTION_INDICATOR;
+        function-enumerator = <0>;
+        default-state = "on";
+      };
+
+      led@3 {
+        reg = <3>;
+        color = <LED_COLOR_ID_GREEN>;
+        function = LED_FUNCTION_INDICATOR;
+        function-enumerator = <2>;
+      };
+
+      led@4 {
+        reg = <4>;
+        color = <LED_COLOR_ID_GREEN>;
+        function = LED_FUNCTION_INDICATOR;
+        function-enumerator = <3>;
+      };
+    };
+  - |
+    #include <dt-bindings/leds/common.h>
+
+    led-controller {
+      compatible = "qcom,pmi8994-lpg";
+
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      qcom,power-source = <1>;
+
+      multi-led {
+        color = <LED_COLOR_ID_RGB>;
+        function = LED_FUNCTION_STATUS;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        led@1 {
+          reg = <1>;
+          color = <LED_COLOR_ID_RED>;
+        };
+
+        led@2 {
+          reg = <2>;
+          color = <LED_COLOR_ID_GREEN>;
+        };
+
+        led@3 {
+          reg = <3>;
+          color = <LED_COLOR_ID_BLUE>;
+        };
+      };
+    };
+  - |
+    pwm-controller {
+      compatible = "qcom,pm8916-pwm";
+      #pwm-cells = <2>;
+    };
+...
-- 
2.29.2

[PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Bjorn Andersson]

The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
with their output being routed to various other components, such as
current sinks or GPIOs.

Each LPG instance can operate on fixed parameters or based on a shared
lookup-table, altering the duty cycle over time. This provides the means
for hardware assisted transitions of LED brightness.

A typical use case for the fixed parameter mode is to drive a PWM
backlight control signal, the driver therefor allows each LPG instance
to be exposed to the kernel either through the LED framework or the PWM
framework.

A typical use case for the LED configuration is to drive RGB LEDs in
smartphones etc, for which the driver support multiple channels to be
ganged up to a MULTICOLOR LED. In this configuration the pattern
generators will be synchronized, to allow for multi-color patterns.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---

Change since v9:
- Replac magic 381 second as upper bound of period length
- Declare variables inside the blocks where they are used in lpg_calc_freq()
- Reworked duty calculation to avoid loosing precision
- Reject inverted polarity in pwm_apply

 drivers/leds/Kconfig             |    3 +
 drivers/leds/Makefile            |    3 +
 drivers/leds/rgb/Kconfig         |   13 +
 drivers/leds/rgb/Makefile        |    3 +
 drivers/leds/rgb/leds-qcom-lpg.c | 1302 ++++++++++++++++++++++++++++++
 5 files changed, 1324 insertions(+)
 create mode 100644 drivers/leds/rgb/Kconfig
 create mode 100644 drivers/leds/rgb/Makefile
 create mode 100644 drivers/leds/rgb/leds-qcom-lpg.c

diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
index ed800f5da7d8..ffb8777842ff 100644
--- a/drivers/leds/Kconfig
+++ b/drivers/leds/Kconfig
@@ -876,6 +876,9 @@ source "drivers/leds/blink/Kconfig"
 comment "Flash and Torch LED drivers"
 source "drivers/leds/flash/Kconfig"
 
+comment "RGB LED drivers"
+source "drivers/leds/rgb/Kconfig"
+
 comment "LED Triggers"
 source "drivers/leds/trigger/Kconfig"
 
diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
index c636ec069612..351153f84070 100644
--- a/drivers/leds/Makefile
+++ b/drivers/leds/Makefile
@@ -100,6 +100,9 @@ obj-$(CONFIG_LEDS_USER)			+= uleds.o
 # Flash and Torch LED Drivers
 obj-$(CONFIG_LEDS_CLASS_FLASH)		+= flash/
 
+# RGB LED Drivers
+obj-$(CONFIG_LEDS_CLASS_MULTICOLOR)	+= rgb/
+
 # LED Triggers
 obj-$(CONFIG_LEDS_TRIGGERS)		+= trigger/
 
diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig
new file mode 100644
index 000000000000..20be3e11fe4a
--- /dev/null
+++ b/drivers/leds/rgb/Kconfig
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+
+if LEDS_CLASS_MULTICOLOR
+
+config LEDS_QCOM_LPG
+	tristate "LED support for Qualcomm LPG"
+	depends on OF
+	depends on SPMI
+	help
+	  This option enables support for the Light Pulse Generator found in a
+	  wide variety of Qualcomm PMICs.
+
+endif # LEDS_CLASS_MULTICOLOR
diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile
new file mode 100644
index 000000000000..83114f44c4ea
--- /dev/null
+++ b/drivers/leds/rgb/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_LEDS_QCOM_LPG)	+= leds-qcom-lpg.o
diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
new file mode 100644
index 000000000000..45ef4ec5ff17
--- /dev/null
+++ b/drivers/leds/rgb/leds-qcom-lpg.c
@@ -0,0 +1,1302 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017-2021 Linaro Ltd
+ * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
+ */
+#include <linux/bits.h>
+#include <linux/led-class-multicolor.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define LPG_PATTERN_CONFIG_REG	0x40
+#define LPG_SIZE_CLK_REG	0x41
+#define LPG_PREDIV_CLK_REG	0x42
+#define PWM_TYPE_CONFIG_REG	0x43
+#define PWM_VALUE_REG		0x44
+#define PWM_ENABLE_CONTROL_REG	0x46
+#define PWM_SYNC_REG		0x47
+#define LPG_RAMP_DURATION_REG	0x50
+#define LPG_HI_PAUSE_REG	0x52
+#define LPG_LO_PAUSE_REG	0x54
+#define LPG_HI_IDX_REG		0x56
+#define LPG_LO_IDX_REG		0x57
+#define PWM_SEC_ACCESS_REG	0xd0
+#define PWM_DTEST_REG(x)	(0xe2 + (x) - 1)
+
+#define TRI_LED_SRC_SEL		0x45
+#define TRI_LED_EN_CTL		0x46
+#define TRI_LED_ATC_CTL		0x47
+
+#define LPG_LUT_REG(x)		(0x40 + (x) * 2)
+#define RAMP_CONTROL_REG	0xc8
+
+#define LPG_RESOLUTION		512
+#define LPG_MAX_M		7
+
+struct lpg_channel;
+struct lpg_data;
+
+/**
+ * struct lpg - LPG device context
+ * @dev:	struct device for LPG device
+ * @map:	regmap for register access
+ * @pwm:	PWM-chip object, if operating in PWM mode
+ * @data:	reference to version specific data
+ * @lut_base:	base address of the LUT block (optional)
+ * @lut_size:	number of entries in the LUT block
+ * @lut_bitmap:	allocation bitmap for LUT entries
+ * @triled_base: base address of the TRILED block (optional)
+ * @triled_src:	power-source for the TRILED
+ * @triled_has_atc_ctl:	true if there is TRI_LED_ATC_CTL register
+ * @triled_has_src_sel:	true if there is TRI_LED_SRC_SEL register
+ * @channels:	list of PWM channels
+ * @num_channels: number of @channels
+ */
+struct lpg {
+	struct device *dev;
+	struct regmap *map;
+
+	struct pwm_chip pwm;
+
+	const struct lpg_data *data;
+
+	u32 lut_base;
+	u32 lut_size;
+	unsigned long *lut_bitmap;
+
+	u32 triled_base;
+	u32 triled_src;
+	bool triled_has_atc_ctl;
+	bool triled_has_src_sel;
+
+	struct lpg_channel *channels;
+	unsigned int num_channels;
+};
+
+/**
+ * struct lpg_channel - per channel data
+ * @lpg:	reference to parent lpg
+ * @base:	base address of the PWM channel
+ * @triled_mask: mask in TRILED to enable this channel
+ * @lut_mask:	mask in LUT to start pattern generator for this channel
+ * @in_use:	channel is exposed to LED framework
+ * @color:	color of the LED attached to this channel
+ * @dtest_line:	DTEST line for output, or 0 if disabled
+ * @dtest_value: DTEST line configuration
+ * @pwm_value:	duty (in microseconds) of the generated pulses, overridden by LUT
+ * @enabled:	output enabled?
+ * @period:	period (in nanoseconds) of the generated pulses
+ * @clk:	base frequency of the clock generator
+ * @pre_div:	divider of @clk
+ * @pre_div_exp: exponential divider of @clk
+ * @ramp_enabled: duty cycle is driven by iterating over lookup table
+ * @ramp_ping_pong: reverse through pattern, rather than wrapping to start
+ * @ramp_oneshot: perform only a single pass over the pattern
+ * @ramp_reverse: iterate over pattern backwards
+ * @ramp_tick_ms: length (in milliseconds) of one step in the pattern
+ * @ramp_lo_pause_ms: pause (in milliseconds) before iterating over pattern
+ * @ramp_hi_pause_ms: pause (in milliseconds) after iterating over pattern
+ * @pattern_lo_idx: start index of associated pattern
+ * @pattern_hi_idx: last index of associated pattern
+ */
+struct lpg_channel {
+	struct lpg *lpg;
+
+	u32 base;
+	unsigned int triled_mask;
+	unsigned int lut_mask;
+
+	bool in_use;
+
+	int color;
+
+	u32 dtest_line;
+	u32 dtest_value;
+
+	u16 pwm_value;
+	bool enabled;
+
+	u64 period;
+	unsigned int clk;
+	unsigned int pre_div;
+	unsigned int pre_div_exp;
+
+	bool ramp_enabled;
+	bool ramp_ping_pong;
+	bool ramp_oneshot;
+	bool ramp_reverse;
+	unsigned long ramp_tick_ms;
+	unsigned long ramp_lo_pause_ms;
+	unsigned long ramp_hi_pause_ms;
+
+	unsigned int pattern_lo_idx;
+	unsigned int pattern_hi_idx;
+};
+
+/**
+ * struct lpg_led - logical LED object
+ * @lpg:		lpg context reference
+ * @cdev:		LED class device
+ * @mcdev:		Multicolor LED class device
+ * @num_channels:	number of @channels
+ * @channels:		list of channels associated with the LED
+ */
+struct lpg_led {
+	struct lpg *lpg;
+
+	struct led_classdev cdev;
+	struct led_classdev_mc mcdev;
+
+	unsigned int num_channels;
+	struct lpg_channel *channels[];
+};
+
+/**
+ * struct lpg_channel_data - per channel initialization data
+ * @base:		base address for PWM channel registers
+ * @triled_mask:	bitmask for controlling this channel in TRILED
+ */
+struct lpg_channel_data {
+	unsigned int base;
+	u8 triled_mask;
+};
+
+/**
+ * struct lpg_data - initialization data
+ * @lut_base:		base address of LUT block
+ * @lut_size:		number of entries in LUT
+ * @triled_base:	base address of TRILED
+ * @triled_has_atc_ctl:	true if there is TRI_LED_ATC_CTL register
+ * @triled_has_src_sel:	true if there is TRI_LED_SRC_SEL register
+ * @pwm_9bit_mask:	bitmask for switching from 6bit to 9bit pwm
+ * @num_channels:	number of channels in LPG
+ * @channels:		list of channel initialization data
+ */
+struct lpg_data {
+	unsigned int lut_base;
+	unsigned int lut_size;
+	unsigned int triled_base;
+	bool triled_has_atc_ctl;
+	bool triled_has_src_sel;
+	unsigned int pwm_9bit_mask;
+	int num_channels;
+	const struct lpg_channel_data *channels;
+};
+
+static int triled_set(struct lpg *lpg, unsigned int mask, unsigned int enable)
+{
+	/* Skip if we don't have a triled block */
+	if (!lpg->triled_base)
+		return 0;
+
+	return regmap_update_bits(lpg->map, lpg->triled_base + TRI_LED_EN_CTL,
+				  mask, enable);
+}
+
+static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
+			 size_t len, unsigned int *lo_idx, unsigned int *hi_idx)
+{
+	unsigned int idx;
+	u16 val;
+	int i;
+
+	/* Hardware does not behave when LO_IDX == HI_IDX */
+	if (len == 1)
+		return -EINVAL;
+
+	idx = bitmap_find_next_zero_area(lpg->lut_bitmap, lpg->lut_size,
+					 0, len, 0);
+	if (idx >= lpg->lut_size)
+		return -ENOMEM;
+
+	for (i = 0; i < len; i++) {
+		val = pattern[i].brightness;
+
+		regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
+				  &val, sizeof(val));
+	}
+
+	bitmap_set(lpg->lut_bitmap, idx, len);
+
+	*lo_idx = idx;
+	*hi_idx = idx + len - 1;
+
+	return 0;
+}
+
+static void lpg_lut_free(struct lpg *lpg, unsigned int lo_idx, unsigned int hi_idx)
+{
+	int len;
+
+	if (lo_idx == hi_idx)
+		return;
+
+	len = hi_idx - lo_idx + 1;
+	bitmap_clear(lpg->lut_bitmap, lo_idx, len);
+}
+
+static int lpg_lut_sync(struct lpg *lpg, unsigned int mask)
+{
+	return regmap_write(lpg->map, lpg->lut_base + RAMP_CONTROL_REG, mask);
+}
+
+static const unsigned int lpg_clk_rates[] = {1024, 32768, 19200000};
+static const unsigned int lpg_pre_divs[] = {1, 3, 5, 6};
+
+static int lpg_calc_freq(struct lpg_channel *chan, uint64_t period)
+{
+	unsigned int clk, best_clk = 0;
+	unsigned int div, best_div = 0;
+	unsigned int m, best_m = 0;
+	unsigned int error;
+	unsigned int best_err = UINT_MAX;
+	u64 best_period = 0;
+
+	/*
+	 * The PWM period is determined by:
+	 *
+	 *          resolution * pre_div * 2^M
+	 * period = --------------------------
+	 *                   refclk
+	 *
+	 * With resolution fixed at 2^9 bits, pre_div = {1, 3, 5, 6} and
+	 * M = [0..7].
+	 *
+	 * This allows for periods between 27uS and 384s, as the PWM framework
+	 * wants a period of equal or lower length than requested, reject
+	 * anything below 27uS.
+	 */
+	if (period <= (u64)NSEC_PER_SEC * LPG_RESOLUTION / 19200000)
+		return -EINVAL;
+
+	/* Limit period to largest possible value, to avoid overflows */
+	if (period > (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 1024)
+		period = (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 2014;
+
+	/*
+	 * Search for the pre_div, clk and M by solving the rewritten formula
+	 * for each clk and pre_div value:
+	 *
+	 *                       period * clk
+	 * M = log2 -------------------------------------
+	 *           NSEC_PER_SEC * pre_div * resolution
+	 */
+	for (clk = 0; clk < ARRAY_SIZE(lpg_clk_rates); clk++) {
+		u64 nom = period * lpg_clk_rates[clk];
+
+		for (div = 0; div < ARRAY_SIZE(lpg_pre_divs); div++) {
+			u64 denom = (u64)NSEC_PER_SEC * lpg_pre_divs[div] * (1 << 9);
+			u64 actual;
+			u64 ratio;
+
+			if (nom < denom)
+				continue;
+
+			ratio = div64_u64(nom, denom);
+			m = ilog2(ratio);
+			if (m > LPG_MAX_M)
+				m = LPG_MAX_M;
+
+			actual = DIV_ROUND_UP_ULL(denom * (1 << m), lpg_clk_rates[clk]);
+
+			error = period - actual;
+			if (error < best_err) {
+				best_err = error;
+
+				best_div = div;
+				best_m = m;
+				best_clk = clk;
+				best_period = actual;
+			}
+		}
+	}
+
+	chan->clk = best_clk;
+	chan->pre_div = best_div;
+	chan->pre_div_exp = best_m;
+	chan->period = best_period;
+
+	return 0;
+}
+
+static void lpg_calc_duty(struct lpg_channel *chan, uint64_t duty)
+{
+	unsigned int max = LPG_RESOLUTION - 1;
+	unsigned int val;
+
+	val = div64_u64(duty * lpg_clk_rates[chan->clk],
+			(u64)NSEC_PER_SEC * lpg_pre_divs[chan->pre_div] * (1 << chan->pre_div_exp));
+
+	chan->pwm_value = min(val, max);
+}
+
+static void lpg_apply_freq(struct lpg_channel *chan)
+{
+	unsigned long val;
+	struct lpg *lpg = chan->lpg;
+
+	if (!chan->enabled)
+		return;
+
+	/* Clock register values are off-by-one from lpg_clk_table */
+	val = chan->clk + 1;
+
+	/* Enable 9bit resolution */
+	val |= lpg->data->pwm_9bit_mask;
+
+	regmap_write(lpg->map, chan->base + LPG_SIZE_CLK_REG, val);
+
+	val = chan->pre_div << 5 | chan->pre_div_exp;
+	regmap_write(lpg->map, chan->base + LPG_PREDIV_CLK_REG, val);
+}
+
+#define LPG_ENABLE_GLITCH_REMOVAL	BIT(5)
+
+static void lpg_enable_glitch(struct lpg_channel *chan)
+{
+	struct lpg *lpg = chan->lpg;
+
+	regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
+			   LPG_ENABLE_GLITCH_REMOVAL, 0);
+}
+
+static void lpg_disable_glitch(struct lpg_channel *chan)
+{
+	struct lpg *lpg = chan->lpg;
+
+	regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
+			   LPG_ENABLE_GLITCH_REMOVAL,
+			   LPG_ENABLE_GLITCH_REMOVAL);
+}
+
+static void lpg_apply_pwm_value(struct lpg_channel *chan)
+{
+	struct lpg *lpg = chan->lpg;
+	u16 val = chan->pwm_value;
+
+	if (!chan->enabled)
+		return;
+
+	regmap_bulk_write(lpg->map, chan->base + PWM_VALUE_REG, &val, sizeof(val));
+}
+
+#define LPG_PATTERN_CONFIG_LO_TO_HI	BIT(4)
+#define LPG_PATTERN_CONFIG_REPEAT	BIT(3)
+#define LPG_PATTERN_CONFIG_TOGGLE	BIT(2)
+#define LPG_PATTERN_CONFIG_PAUSE_HI	BIT(1)
+#define LPG_PATTERN_CONFIG_PAUSE_LO	BIT(0)
+
+static void lpg_apply_lut_control(struct lpg_channel *chan)
+{
+	struct lpg *lpg = chan->lpg;
+	unsigned int hi_pause;
+	unsigned int lo_pause;
+	unsigned int conf = 0;
+	unsigned int step = chan->ramp_tick_ms;
+	unsigned int lo_idx = chan->pattern_lo_idx;
+	unsigned int hi_idx = chan->pattern_hi_idx;
+
+	if (!chan->ramp_enabled || chan->pattern_lo_idx == chan->pattern_hi_idx)
+		return;
+
+	hi_pause = DIV_ROUND_UP(chan->ramp_hi_pause_ms, step);
+	lo_pause = DIV_ROUND_UP(chan->ramp_lo_pause_ms, step);
+
+	if (!chan->ramp_reverse)
+		conf |= LPG_PATTERN_CONFIG_LO_TO_HI;
+	if (!chan->ramp_oneshot)
+		conf |= LPG_PATTERN_CONFIG_REPEAT;
+	if (chan->ramp_ping_pong)
+		conf |= LPG_PATTERN_CONFIG_TOGGLE;
+	if (chan->ramp_hi_pause_ms)
+		conf |= LPG_PATTERN_CONFIG_PAUSE_HI;
+	if (chan->ramp_lo_pause_ms)
+		conf |= LPG_PATTERN_CONFIG_PAUSE_LO;
+
+	regmap_write(lpg->map, chan->base + LPG_PATTERN_CONFIG_REG, conf);
+	regmap_write(lpg->map, chan->base + LPG_HI_IDX_REG, hi_idx);
+	regmap_write(lpg->map, chan->base + LPG_LO_IDX_REG, lo_idx);
+
+	regmap_write(lpg->map, chan->base + LPG_RAMP_DURATION_REG, step);
+	regmap_write(lpg->map, chan->base + LPG_HI_PAUSE_REG, hi_pause);
+	regmap_write(lpg->map, chan->base + LPG_LO_PAUSE_REG, lo_pause);
+}
+
+#define LPG_ENABLE_CONTROL_OUTPUT		BIT(7)
+#define LPG_ENABLE_CONTROL_BUFFER_TRISTATE	BIT(5)
+#define LPG_ENABLE_CONTROL_SRC_PWM		BIT(2)
+#define LPG_ENABLE_CONTROL_RAMP_GEN		BIT(1)
+
+static void lpg_apply_control(struct lpg_channel *chan)
+{
+	unsigned int ctrl;
+	struct lpg *lpg = chan->lpg;
+
+	ctrl = LPG_ENABLE_CONTROL_BUFFER_TRISTATE;
+
+	if (chan->enabled)
+		ctrl |= LPG_ENABLE_CONTROL_OUTPUT;
+
+	if (chan->pattern_lo_idx != chan->pattern_hi_idx)
+		ctrl |= LPG_ENABLE_CONTROL_RAMP_GEN;
+	else
+		ctrl |= LPG_ENABLE_CONTROL_SRC_PWM;
+
+	regmap_write(lpg->map, chan->base + PWM_ENABLE_CONTROL_REG, ctrl);
+
+	/*
+	 * Due to LPG hardware bug, in the PWM mode, having enabled PWM,
+	 * We have to write PWM values one more time.
+	 */
+	if (chan->enabled)
+		lpg_apply_pwm_value(chan);
+}
+
+#define LPG_SYNC_PWM	BIT(0)
+
+static void lpg_apply_sync(struct lpg_channel *chan)
+{
+	struct lpg *lpg = chan->lpg;
+
+	regmap_write(lpg->map, chan->base + PWM_SYNC_REG, LPG_SYNC_PWM);
+}
+
+static int lpg_parse_dtest(struct lpg *lpg)
+{
+	struct lpg_channel *chan;
+	struct device_node *np = lpg->dev->of_node;
+	int count;
+	int ret;
+	int i;
+
+	count = of_property_count_u32_elems(np, "qcom,dtest");
+	if (count == -EINVAL) {
+		return 0;
+	} else if (count < 0) {
+		ret = count;
+		goto err_malformed;
+	} else if (count != lpg->data->num_channels * 2) {
+		dev_err(lpg->dev, "qcom,dtest needs to be %d items\n",
+			lpg->data->num_channels * 2);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < lpg->data->num_channels; i++) {
+		chan = &lpg->channels[i];
+
+		ret = of_property_read_u32_index(np, "qcom,dtest", i * 2,
+						 &chan->dtest_line);
+		if (ret)
+			goto err_malformed;
+
+		ret = of_property_read_u32_index(np, "qcom,dtest", i * 2 + 1,
+						 &chan->dtest_value);
+		if (ret)
+			goto err_malformed;
+	}
+
+	return 0;
+
+err_malformed:
+	dev_err(lpg->dev, "malformed qcom,dtest\n");
+	return ret;
+}
+
+static void lpg_apply_dtest(struct lpg_channel *chan)
+{
+	struct lpg *lpg = chan->lpg;
+
+	if (!chan->dtest_line)
+		return;
+
+	regmap_write(lpg->map, chan->base + PWM_SEC_ACCESS_REG, 0xa5);
+	regmap_write(lpg->map, chan->base + PWM_DTEST_REG(chan->dtest_line),
+		     chan->dtest_value);
+}
+
+static void lpg_apply(struct lpg_channel *chan)
+{
+	lpg_disable_glitch(chan);
+	lpg_apply_freq(chan);
+	lpg_apply_pwm_value(chan);
+	lpg_apply_control(chan);
+	lpg_apply_sync(chan);
+	lpg_apply_lut_control(chan);
+	lpg_enable_glitch(chan);
+}
+
+static void lpg_brightness_set(struct lpg_led *led, struct led_classdev *cdev,
+			       struct mc_subled *subleds)
+{
+	enum led_brightness brightness;
+	struct lpg_channel *chan;
+	unsigned int triled_enabled = 0;
+	unsigned int triled_mask = 0;
+	unsigned int lut_mask = 0;
+	unsigned int duty;
+	struct lpg *lpg = led->lpg;
+	int i;
+
+	for (i = 0; i < led->num_channels; i++) {
+		chan = led->channels[i];
+		brightness = subleds[i].brightness;
+
+		if (brightness == LED_OFF) {
+			chan->enabled = false;
+			chan->ramp_enabled = false;
+		} else if (chan->pattern_lo_idx != chan->pattern_hi_idx) {
+			lpg_calc_freq(chan, NSEC_PER_MSEC);
+
+			chan->enabled = true;
+			chan->ramp_enabled = true;
+
+			lut_mask |= chan->lut_mask;
+			triled_enabled |= chan->triled_mask;
+		} else {
+			lpg_calc_freq(chan, NSEC_PER_MSEC);
+
+			duty = div_u64(brightness * chan->period, cdev->max_brightness);
+			lpg_calc_duty(chan, duty);
+			chan->enabled = true;
+			chan->ramp_enabled = false;
+
+			triled_enabled |= chan->triled_mask;
+		}
+
+		triled_mask |= chan->triled_mask;
+
+		lpg_apply(chan);
+	}
+
+	/* Toggle triled lines */
+	if (triled_mask)
+		triled_set(lpg, triled_mask, triled_enabled);
+
+	/* Trigger start of ramp generator(s) */
+	if (lut_mask)
+		lpg_lut_sync(lpg, lut_mask);
+}
+
+static void lpg_brightness_single_set(struct led_classdev *cdev,
+				      enum led_brightness value)
+{
+	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+	struct mc_subled info;
+
+	info.brightness = value;
+	lpg_brightness_set(led, cdev, &info);
+}
+
+static void lpg_brightness_mc_set(struct led_classdev *cdev,
+				  enum led_brightness value)
+{
+	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+
+	led_mc_calc_color_components(mc, value);
+	lpg_brightness_set(led, cdev, mc->subled_info);
+}
+
+static int lpg_blink_set(struct lpg_led *led,
+			 unsigned long *delay_on, unsigned long *delay_off)
+{
+	struct lpg_channel *chan;
+	unsigned int period;
+	unsigned int triled_mask = 0;
+	struct lpg *lpg = led->lpg;
+	u64 duty;
+	int i;
+
+	if (!*delay_on && !*delay_off) {
+		*delay_on = 500;
+		*delay_off = 500;
+	}
+
+	duty = *delay_on * NSEC_PER_MSEC;
+	period = (*delay_on + *delay_off) * NSEC_PER_MSEC;
+
+	for (i = 0; i < led->num_channels; i++) {
+		chan = led->channels[i];
+
+		lpg_calc_freq(chan, period);
+		lpg_calc_duty(chan, duty);
+
+		chan->enabled = true;
+		chan->ramp_enabled = false;
+
+		triled_mask |= chan->triled_mask;
+
+		lpg_apply(chan);
+	}
+
+	/* Enable triled lines */
+	triled_set(lpg, triled_mask, triled_mask);
+
+	chan = led->channels[0];
+	duty = div_u64(chan->pwm_value * chan->period, LPG_RESOLUTION);
+	*delay_on = div_u64(duty, NSEC_PER_MSEC);
+	*delay_off = div_u64(chan->period - duty, NSEC_PER_MSEC);
+
+	return 0;
+}
+
+static int lpg_blink_single_set(struct led_classdev *cdev,
+				unsigned long *delay_on, unsigned long *delay_off)
+{
+	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+
+	return lpg_blink_set(led, delay_on, delay_off);
+}
+
+static int lpg_blink_mc_set(struct led_classdev *cdev,
+			    unsigned long *delay_on, unsigned long *delay_off)
+{
+	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+
+	return lpg_blink_set(led, delay_on, delay_off);
+}
+
+static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *pattern,
+			   u32 len, int repeat)
+{
+	struct lpg_channel *chan;
+	struct lpg *lpg = led->lpg;
+	unsigned int hi_pause;
+	unsigned int lo_pause;
+	unsigned int lo_idx;
+	unsigned int hi_idx;
+	bool ping_pong = true;
+	int brightness_a;
+	int brightness_b;
+	int ret;
+	int i;
+
+	/* Only support oneshot or indefinite loops, due to limited pattern space */
+	if (repeat != -1 && repeat != 1)
+		return -EINVAL;
+
+	/*
+	 * The LPG plays patterns with at a fixed pace, a "low pause" can be
+	 * performed before the pattern and a "high pause" after. In order to
+	 * save space the pattern can be played in "ping pong" mode, in which
+	 * the pattern is first played forward, then "high pause" is applied,
+	 * then the pattern is played backwards and finally the "low pause" is
+	 * applied.
+	 *
+	 * The delta_t of the first entry is used to determine the pace of the
+	 * pattern.
+	 *
+	 * If the specified pattern is a palindrome the ping pong mode is
+	 * enabled. In this scenario the delta_t of the last entry determines
+	 * the "low pause" time and the delta_t of the middle entry (i.e. the
+	 * last in the programmed pattern) determines the "high pause". If the
+	 * pattern consists of an odd number of values, no "high pause" is
+	 * used.
+	 *
+	 * When ping pong mode is not selected, the delta_t of the last entry
+	 * is used as "high pause". No "low pause" is used.
+	 *
+	 * delta_t of any other members of the pattern is ignored.
+	 */
+
+	/* Detect palindromes and use "ping pong" to reduce LUT usage */
+	for (i = 0; i < len / 2; i++) {
+		brightness_a = pattern[i].brightness;
+		brightness_b = pattern[len - i - 1].brightness;
+
+		if (brightness_a != brightness_b) {
+			ping_pong = false;
+			break;
+		}
+	}
+
+	if (ping_pong) {
+		if (len % 2)
+			hi_pause = 0;
+		else
+			hi_pause = pattern[(len + 1) / 2].delta_t;
+		lo_pause = pattern[len - 1].delta_t;
+
+		len = (len + 1) / 2;
+	} else {
+		hi_pause = pattern[len - 1].delta_t;
+		lo_pause = 0;
+	}
+
+	ret = lpg_lut_store(lpg, pattern, len, &lo_idx, &hi_idx);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < led->num_channels; i++) {
+		chan = led->channels[i];
+
+		chan->ramp_tick_ms = pattern[0].delta_t;
+		chan->ramp_ping_pong = ping_pong;
+		chan->ramp_oneshot = repeat != -1;
+
+		chan->ramp_lo_pause_ms = lo_pause;
+		chan->ramp_hi_pause_ms = hi_pause;
+
+		chan->pattern_lo_idx = lo_idx;
+		chan->pattern_hi_idx = hi_idx;
+	}
+
+	return 0;
+}
+
+static int lpg_pattern_single_set(struct led_classdev *cdev,
+				  struct led_pattern *pattern, u32 len,
+				  int repeat)
+{
+	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+	int ret;
+
+	ret = lpg_pattern_set(led, pattern, len, repeat);
+	if (ret < 0)
+		return ret;
+
+	lpg_brightness_single_set(cdev, LED_FULL);
+
+	return 0;
+}
+
+static int lpg_pattern_mc_set(struct led_classdev *cdev,
+			      struct led_pattern *pattern, u32 len,
+			      int repeat)
+{
+	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+	int ret;
+
+	ret = lpg_pattern_set(led, pattern, len, repeat);
+	if (ret < 0)
+		return ret;
+
+	led_mc_calc_color_components(mc, LED_FULL);
+	lpg_brightness_set(led, cdev, mc->subled_info);
+
+	return 0;
+}
+
+static int lpg_pattern_clear(struct lpg_led *led)
+{
+	struct lpg_channel *chan;
+	struct lpg *lpg = led->lpg;
+	int i;
+
+	chan = led->channels[0];
+	lpg_lut_free(lpg, chan->pattern_lo_idx, chan->pattern_hi_idx);
+
+	for (i = 0; i < led->num_channels; i++) {
+		chan = led->channels[i];
+		chan->pattern_lo_idx = 0;
+		chan->pattern_hi_idx = 0;
+	}
+
+	return 0;
+}
+
+static int lpg_pattern_single_clear(struct led_classdev *cdev)
+{
+	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
+
+	return lpg_pattern_clear(led);
+}
+
+static int lpg_pattern_mc_clear(struct led_classdev *cdev)
+{
+	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
+	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
+
+	return lpg_pattern_clear(led);
+}
+
+static int lpg_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+	struct lpg *lpg = container_of(chip, struct lpg, pwm);
+	struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
+
+	return chan->in_use ? -EBUSY : 0;
+}
+
+/*
+ * Limitations:
+ * - Updating both duty and period is not done atomically, so the output signal
+ *   will momentarily be a mix of the settings.
+ */
+static int lpg_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+			 const struct pwm_state *state)
+{
+	struct lpg *lpg = container_of(chip, struct lpg, pwm);
+	struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
+	int ret;
+
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
+	ret = lpg_calc_freq(chan, state->period);
+	if (ret < 0)
+		return ret;
+
+	lpg_calc_duty(chan, state->duty_cycle);
+	chan->enabled = state->enabled;
+
+	lpg_apply(chan);
+
+	triled_set(lpg, chan->triled_mask, chan->enabled ? chan->triled_mask : 0);
+
+	return 0;
+}
+
+static void lpg_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+			      struct pwm_state *state)
+{
+	struct lpg *lpg = container_of(chip, struct lpg, pwm);
+	struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
+	u64 duty = DIV_ROUND_UP_ULL(chan->pwm_value * chan->period, LPG_RESOLUTION - 1);
+
+	state->period = chan->period;
+	state->duty_cycle = duty;
+	state->polarity = PWM_POLARITY_NORMAL;
+	state->enabled = chan->enabled;
+}
+
+static const struct pwm_ops lpg_pwm_ops = {
+	.request = lpg_pwm_request,
+	.apply = lpg_pwm_apply,
+	.get_state = lpg_pwm_get_state,
+	.owner = THIS_MODULE,
+};
+
+static int lpg_add_pwm(struct lpg *lpg)
+{
+	int ret;
+
+	lpg->pwm.base = -1;
+	lpg->pwm.dev = lpg->dev;
+	lpg->pwm.npwm = lpg->num_channels;
+	lpg->pwm.ops = &lpg_pwm_ops;
+
+	ret = pwmchip_add(&lpg->pwm);
+	if (ret)
+		dev_err(lpg->dev, "failed to add PWM chip: ret %d\n", ret);
+
+	return ret;
+}
+
+static int lpg_parse_channel(struct lpg *lpg, struct device_node *np,
+			     struct lpg_channel **channel)
+{
+	struct lpg_channel *chan;
+	u32 color = LED_COLOR_ID_GREEN;
+	u32 reg;
+	int ret;
+
+	ret = of_property_read_u32(np, "reg", &reg);
+	if (ret || !reg || reg > lpg->num_channels) {
+		dev_err(lpg->dev, "invalid \"reg\" of %pOFn\n", np);
+		return -EINVAL;
+	}
+
+	chan = &lpg->channels[reg - 1];
+	chan->in_use = true;
+
+	ret = of_property_read_u32(np, "color", &color);
+	if (ret < 0 && ret != -EINVAL) {
+		dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
+		return ret;
+	}
+
+	chan->color = color;
+
+	*channel = chan;
+
+	return 0;
+}
+
+static int lpg_add_led(struct lpg *lpg, struct device_node *np)
+{
+	struct led_init_data init_data = {};
+	struct led_classdev *cdev;
+	struct device_node *child;
+	struct mc_subled *info;
+	struct lpg_led *led;
+	const char *state;
+	int num_channels;
+	u32 color = 0;
+	int ret;
+	int i;
+
+	ret = of_property_read_u32(np, "color", &color);
+	if (ret < 0 && ret != -EINVAL) {
+		dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
+		return ret;
+	}
+
+	if (color == LED_COLOR_ID_RGB)
+		num_channels = of_get_available_child_count(np);
+	else
+		num_channels = 1;
+
+	led = devm_kzalloc(lpg->dev, struct_size(led, channels, num_channels), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	led->lpg = lpg;
+	led->num_channels = num_channels;
+
+	if (color == LED_COLOR_ID_RGB) {
+		info = devm_kcalloc(lpg->dev, num_channels, sizeof(*info), GFP_KERNEL);
+		if (!info)
+			return -ENOMEM;
+		i = 0;
+		for_each_available_child_of_node(np, child) {
+			ret = lpg_parse_channel(lpg, child, &led->channels[i]);
+			if (ret < 0)
+				return ret;
+
+			info[i].color_index = led->channels[i]->color;
+			info[i].intensity = LED_FULL;
+			i++;
+		}
+
+		led->mcdev.subled_info = info;
+		led->mcdev.num_colors = num_channels;
+
+		cdev = &led->mcdev.led_cdev;
+		cdev->brightness_set = lpg_brightness_mc_set;
+		cdev->blink_set = lpg_blink_mc_set;
+
+		/* Register pattern accessors only if we have a LUT block */
+		if (lpg->lut_base) {
+			cdev->pattern_set = lpg_pattern_mc_set;
+			cdev->pattern_clear = lpg_pattern_mc_clear;
+		}
+	} else {
+		ret = lpg_parse_channel(lpg, np, &led->channels[0]);
+		if (ret < 0)
+			return ret;
+
+		cdev = &led->cdev;
+		cdev->brightness_set = lpg_brightness_single_set;
+		cdev->blink_set = lpg_blink_single_set;
+
+		/* Register pattern accessors only if we have a LUT block */
+		if (lpg->lut_base) {
+			cdev->pattern_set = lpg_pattern_single_set;
+			cdev->pattern_clear = lpg_pattern_single_clear;
+		}
+	}
+
+	cdev->default_trigger = of_get_property(np, "linux,default-trigger", NULL);
+	cdev->max_brightness = 255;
+
+	if (!of_property_read_string(np, "default-state", &state) &&
+	    !strcmp(state, "on"))
+		cdev->brightness = LED_FULL;
+	else
+		cdev->brightness = LED_OFF;
+
+	cdev->brightness_set(cdev, cdev->brightness);
+
+	init_data.fwnode = of_fwnode_handle(np);
+
+	if (color == LED_COLOR_ID_RGB)
+		ret = devm_led_classdev_multicolor_register_ext(lpg->dev, &led->mcdev, &init_data);
+	else
+		ret = devm_led_classdev_register_ext(lpg->dev, &led->cdev, &init_data);
+	if (ret)
+		dev_err(lpg->dev, "unable to register %s\n", cdev->name);
+
+	return ret;
+}
+
+static int lpg_init_channels(struct lpg *lpg)
+{
+	const struct lpg_data *data = lpg->data;
+	int i;
+
+	lpg->num_channels = data->num_channels;
+	lpg->channels = devm_kcalloc(lpg->dev, data->num_channels,
+				     sizeof(struct lpg_channel), GFP_KERNEL);
+	if (!lpg->channels)
+		return -ENOMEM;
+
+	for (i = 0; i < data->num_channels; i++) {
+		lpg->channels[i].lpg = lpg;
+		lpg->channels[i].base = data->channels[i].base;
+		lpg->channels[i].triled_mask = data->channels[i].triled_mask;
+		lpg->channels[i].lut_mask = BIT(i);
+	}
+
+	return 0;
+}
+
+static int lpg_init_triled(struct lpg *lpg)
+{
+	struct device_node *np = lpg->dev->of_node;
+	int ret;
+
+	/* Skip initialization if we don't have a triled block */
+	if (!lpg->data->triled_base)
+		return 0;
+
+	lpg->triled_base = lpg->data->triled_base;
+	lpg->triled_has_atc_ctl = lpg->data->triled_has_atc_ctl;
+	lpg->triled_has_src_sel = lpg->data->triled_has_src_sel;
+
+	if (lpg->triled_has_src_sel) {
+		ret = of_property_read_u32(np, "qcom,power-source", &lpg->triled_src);
+		if (ret || lpg->triled_src == 2 || lpg->triled_src > 3) {
+			dev_err(lpg->dev, "invalid power source\n");
+			return -EINVAL;
+		}
+	}
+
+	/* Disable automatic trickle charge LED */
+	if (lpg->triled_has_atc_ctl)
+		regmap_write(lpg->map, lpg->triled_base + TRI_LED_ATC_CTL, 0);
+
+	/* Configure power source */
+	if (lpg->triled_has_src_sel)
+		regmap_write(lpg->map, lpg->triled_base + TRI_LED_SRC_SEL, lpg->triled_src);
+
+	/* Default all outputs to off */
+	regmap_write(lpg->map, lpg->triled_base + TRI_LED_EN_CTL, 0);
+
+	return 0;
+}
+
+static int lpg_init_lut(struct lpg *lpg)
+{
+	const struct lpg_data *data = lpg->data;
+	size_t bitmap_size;
+
+	if (!data->lut_base)
+		return 0;
+
+	lpg->lut_base = data->lut_base;
+	lpg->lut_size = data->lut_size;
+
+	bitmap_size = BITS_TO_BYTES(lpg->lut_size);
+	lpg->lut_bitmap = devm_kzalloc(lpg->dev, bitmap_size, GFP_KERNEL);
+	if (!lpg->lut_bitmap)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int lpg_probe(struct platform_device *pdev)
+{
+	struct device_node *np;
+	struct lpg *lpg;
+	int ret;
+	int i;
+
+	lpg = devm_kzalloc(&pdev->dev, sizeof(*lpg), GFP_KERNEL);
+	if (!lpg)
+		return -ENOMEM;
+
+	lpg->data = of_device_get_match_data(&pdev->dev);
+	if (!lpg->data)
+		return -EINVAL;
+
+	platform_set_drvdata(pdev, lpg);
+
+	lpg->dev = &pdev->dev;
+
+	lpg->map = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!lpg->map) {
+		dev_err(&pdev->dev, "parent regmap unavailable\n");
+		return -ENXIO;
+	}
+
+	ret = lpg_init_channels(lpg);
+	if (ret < 0)
+		return ret;
+
+	ret = lpg_parse_dtest(lpg);
+	if (ret < 0)
+		return ret;
+
+	ret = lpg_init_triled(lpg);
+	if (ret < 0)
+		return ret;
+
+	ret = lpg_init_lut(lpg);
+	if (ret < 0)
+		return ret;
+
+	for_each_available_child_of_node(pdev->dev.of_node, np) {
+		ret = lpg_add_led(lpg, np);
+		if (ret)
+			return ret;
+	}
+
+	for (i = 0; i < lpg->num_channels; i++)
+		lpg_apply_dtest(&lpg->channels[i]);
+
+	return lpg_add_pwm(lpg);
+}
+
+static int lpg_remove(struct platform_device *pdev)
+{
+	struct lpg *lpg = platform_get_drvdata(pdev);
+
+	pwmchip_remove(&lpg->pwm);
+
+	return 0;
+}
+
+static const struct lpg_data pm8916_pwm_data = {
+	.pwm_9bit_mask = BIT(2),
+
+	.num_channels = 1,
+	.channels = (const struct lpg_channel_data[]) {
+		{ .base = 0xbc00 },
+	},
+};
+
+static const struct lpg_data pm8941_lpg_data = {
+	.lut_base = 0xb000,
+	.lut_size = 64,
+
+	.triled_base = 0xd000,
+	.triled_has_atc_ctl = true,
+	.triled_has_src_sel = true,
+
+	.pwm_9bit_mask = 3 << 4,
+
+	.num_channels = 8,
+	.channels = (const struct lpg_channel_data[]) {
+		{ .base = 0xb100 },
+		{ .base = 0xb200 },
+		{ .base = 0xb300 },
+		{ .base = 0xb400 },
+		{ .base = 0xb500, .triled_mask = BIT(5) },
+		{ .base = 0xb600, .triled_mask = BIT(6) },
+		{ .base = 0xb700, .triled_mask = BIT(7) },
+		{ .base = 0xb800 },
+	},
+};
+
+static const struct lpg_data pm8994_lpg_data = {
+	.lut_base = 0xb000,
+	.lut_size = 64,
+
+	.pwm_9bit_mask = 3 << 4,
+
+	.num_channels = 6,
+	.channels = (const struct lpg_channel_data[]) {
+		{ .base = 0xb100 },
+		{ .base = 0xb200 },
+		{ .base = 0xb300 },
+		{ .base = 0xb400 },
+		{ .base = 0xb500 },
+		{ .base = 0xb600 },
+	},
+};
+
+static const struct lpg_data pmi8994_lpg_data = {
+	.lut_base = 0xb000,
+	.lut_size = 24,
+
+	.triled_base = 0xd000,
+	.triled_has_atc_ctl = true,
+	.triled_has_src_sel = true,
+
+	.pwm_9bit_mask = BIT(4),
+
+	.num_channels = 4,
+	.channels = (const struct lpg_channel_data[]) {
+		{ .base = 0xb100, .triled_mask = BIT(5) },
+		{ .base = 0xb200, .triled_mask = BIT(6) },
+		{ .base = 0xb300, .triled_mask = BIT(7) },
+		{ .base = 0xb400 },
+	},
+};
+
+static const struct lpg_data pmi8998_lpg_data = {
+	.lut_base = 0xb000,
+	.lut_size = 49,
+
+	.triled_base = 0xd000,
+
+	.pwm_9bit_mask = BIT(4),
+
+	.num_channels = 6,
+	.channels = (const struct lpg_channel_data[]) {
+		{ .base = 0xb100 },
+		{ .base = 0xb200 },
+		{ .base = 0xb300, .triled_mask = BIT(5) },
+		{ .base = 0xb400, .triled_mask = BIT(6) },
+		{ .base = 0xb500, .triled_mask = BIT(7) },
+		{ .base = 0xb600 },
+	},
+};
+
+static const struct lpg_data pm8150b_lpg_data = {
+	.lut_base = 0xb000,
+	.lut_size = 24,
+
+	.triled_base = 0xd000,
+
+	.pwm_9bit_mask = BIT(4),
+
+	.num_channels = 2,
+	.channels = (const struct lpg_channel_data[]) {
+		{ .base = 0xb100, .triled_mask = BIT(7) },
+		{ .base = 0xb200, .triled_mask = BIT(6) },
+	},
+};
+
+static const struct lpg_data pm8150l_lpg_data = {
+	.lut_base = 0xb000,
+	.lut_size = 48,
+
+	.triled_base = 0xd000,
+
+	.pwm_9bit_mask = BIT(4),
+
+	.num_channels = 5,
+	.channels = (const struct lpg_channel_data[]) {
+		{ .base = 0xb100, .triled_mask = BIT(7) },
+		{ .base = 0xb200, .triled_mask = BIT(6) },
+		{ .base = 0xb300, .triled_mask = BIT(5) },
+		{ .base = 0xbc00 },
+		{ .base = 0xbd00 },
+
+	},
+};
+
+static const struct of_device_id lpg_of_table[] = {
+	{ .compatible = "qcom,pm8150b-lpg", .data = &pm8150b_lpg_data },
+	{ .compatible = "qcom,pm8150l-lpg", .data = &pm8150l_lpg_data },
+	{ .compatible = "qcom,pm8916-pwm", .data = &pm8916_pwm_data },
+	{ .compatible = "qcom,pm8941-lpg", .data = &pm8941_lpg_data },
+	{ .compatible = "qcom,pm8994-lpg", .data = &pm8994_lpg_data },
+	{ .compatible = "qcom,pmi8994-lpg", .data = &pmi8994_lpg_data },
+	{ .compatible = "qcom,pmi8998-lpg", .data = &pmi8998_lpg_data },
+	{ .compatible = "qcom,pmc8180c-lpg", .data = &pm8150l_lpg_data },
+	{}
+};
+MODULE_DEVICE_TABLE(of, lpg_of_table);
+
+static struct platform_driver lpg_driver = {
+	.probe = lpg_probe,
+	.remove = lpg_remove,
+	.driver = {
+		.name = "qcom-spmi-lpg",
+		.of_match_table = lpg_of_table,
+	},
+};
+module_platform_driver(lpg_driver);
+
+MODULE_DESCRIPTION("Qualcomm LPG LED driver");
+MODULE_LICENSE("GPL v2");
-- 
2.29.2

Re: [PATCH v10 1/2] dt-bindings: leds: Add Qualcomm Light Pulse Generator binding

[Rob Herring]

On Sat, 09 Oct 2021 21:39:11 -0700, Bjorn Andersson wrote:
> This adds the binding document describing the three hardware blocks
> related to the Light Pulse Generator found in a wide range of Qualcomm
> PMICs.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---
> 
> Changes since v9:
> - "led" child of "multi-led" now needed a patternProperties
> - use generic "led-controller" and "pwm-controller" in example
> 
>  .../bindings/leds/leds-qcom-lpg.yaml          | 173 ++++++++++++++++++
>  1 file changed, 173 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/leds/leds-qcom-lpg.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Bjorn Andersson]

On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:

> The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> with their output being routed to various other components, such as
> current sinks or GPIOs.
> 
> Each LPG instance can operate on fixed parameters or based on a shared
> lookup-table, altering the duty cycle over time. This provides the means
> for hardware assisted transitions of LED brightness.
> 
> A typical use case for the fixed parameter mode is to drive a PWM
> backlight control signal, the driver therefor allows each LPG instance
> to be exposed to the kernel either through the LED framework or the PWM
> framework.
> 
> A typical use case for the LED configuration is to drive RGB LEDs in
> smartphones etc, for which the driver support multiple channels to be
> ganged up to a MULTICOLOR LED. In this configuration the pattern
> generators will be synchronized, to allow for multi-color patterns.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---

Any feedback on this?

Thanks,
Bjorn

> 
> Change since v9:
> - Replac magic 381 second as upper bound of period length
> - Declare variables inside the blocks where they are used in lpg_calc_freq()
> - Reworked duty calculation to avoid loosing precision
> - Reject inverted polarity in pwm_apply
> 
>  drivers/leds/Kconfig             |    3 +
>  drivers/leds/Makefile            |    3 +
>  drivers/leds/rgb/Kconfig         |   13 +
>  drivers/leds/rgb/Makefile        |    3 +
>  drivers/leds/rgb/leds-qcom-lpg.c | 1302 ++++++++++++++++++++++++++++++
>  5 files changed, 1324 insertions(+)
>  create mode 100644 drivers/leds/rgb/Kconfig
>  create mode 100644 drivers/leds/rgb/Makefile
>  create mode 100644 drivers/leds/rgb/leds-qcom-lpg.c
> 
> diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig
> index ed800f5da7d8..ffb8777842ff 100644
> --- a/drivers/leds/Kconfig
> +++ b/drivers/leds/Kconfig
> @@ -876,6 +876,9 @@ source "drivers/leds/blink/Kconfig"
>  comment "Flash and Torch LED drivers"
>  source "drivers/leds/flash/Kconfig"
>  
> +comment "RGB LED drivers"
> +source "drivers/leds/rgb/Kconfig"
> +
>  comment "LED Triggers"
>  source "drivers/leds/trigger/Kconfig"
>  
> diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile
> index c636ec069612..351153f84070 100644
> --- a/drivers/leds/Makefile
> +++ b/drivers/leds/Makefile
> @@ -100,6 +100,9 @@ obj-$(CONFIG_LEDS_USER)			+= uleds.o
>  # Flash and Torch LED Drivers
>  obj-$(CONFIG_LEDS_CLASS_FLASH)		+= flash/
>  
> +# RGB LED Drivers
> +obj-$(CONFIG_LEDS_CLASS_MULTICOLOR)	+= rgb/
> +
>  # LED Triggers
>  obj-$(CONFIG_LEDS_TRIGGERS)		+= trigger/
>  
> diff --git a/drivers/leds/rgb/Kconfig b/drivers/leds/rgb/Kconfig
> new file mode 100644
> index 000000000000..20be3e11fe4a
> --- /dev/null
> +++ b/drivers/leds/rgb/Kconfig
> @@ -0,0 +1,13 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +if LEDS_CLASS_MULTICOLOR
> +
> +config LEDS_QCOM_LPG
> +	tristate "LED support for Qualcomm LPG"
> +	depends on OF
> +	depends on SPMI
> +	help
> +	  This option enables support for the Light Pulse Generator found in a
> +	  wide variety of Qualcomm PMICs.
> +
> +endif # LEDS_CLASS_MULTICOLOR
> diff --git a/drivers/leds/rgb/Makefile b/drivers/leds/rgb/Makefile
> new file mode 100644
> index 000000000000..83114f44c4ea
> --- /dev/null
> +++ b/drivers/leds/rgb/Makefile
> @@ -0,0 +1,3 @@
> +# SPDX-License-Identifier: GPL-2.0
> +
> +obj-$(CONFIG_LEDS_QCOM_LPG)	+= leds-qcom-lpg.o
> diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
> new file mode 100644
> index 000000000000..45ef4ec5ff17
> --- /dev/null
> +++ b/drivers/leds/rgb/leds-qcom-lpg.c
> @@ -0,0 +1,1302 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2017-2021 Linaro Ltd
> + * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
> + */
> +#include <linux/bits.h>
> +#include <linux/led-class-multicolor.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +#define LPG_PATTERN_CONFIG_REG	0x40
> +#define LPG_SIZE_CLK_REG	0x41
> +#define LPG_PREDIV_CLK_REG	0x42
> +#define PWM_TYPE_CONFIG_REG	0x43
> +#define PWM_VALUE_REG		0x44
> +#define PWM_ENABLE_CONTROL_REG	0x46
> +#define PWM_SYNC_REG		0x47
> +#define LPG_RAMP_DURATION_REG	0x50
> +#define LPG_HI_PAUSE_REG	0x52
> +#define LPG_LO_PAUSE_REG	0x54
> +#define LPG_HI_IDX_REG		0x56
> +#define LPG_LO_IDX_REG		0x57
> +#define PWM_SEC_ACCESS_REG	0xd0
> +#define PWM_DTEST_REG(x)	(0xe2 + (x) - 1)
> +
> +#define TRI_LED_SRC_SEL		0x45
> +#define TRI_LED_EN_CTL		0x46
> +#define TRI_LED_ATC_CTL		0x47
> +
> +#define LPG_LUT_REG(x)		(0x40 + (x) * 2)
> +#define RAMP_CONTROL_REG	0xc8
> +
> +#define LPG_RESOLUTION		512
> +#define LPG_MAX_M		7
> +
> +struct lpg_channel;
> +struct lpg_data;
> +
> +/**
> + * struct lpg - LPG device context
> + * @dev:	struct device for LPG device
> + * @map:	regmap for register access
> + * @pwm:	PWM-chip object, if operating in PWM mode
> + * @data:	reference to version specific data
> + * @lut_base:	base address of the LUT block (optional)
> + * @lut_size:	number of entries in the LUT block
> + * @lut_bitmap:	allocation bitmap for LUT entries
> + * @triled_base: base address of the TRILED block (optional)
> + * @triled_src:	power-source for the TRILED
> + * @triled_has_atc_ctl:	true if there is TRI_LED_ATC_CTL register
> + * @triled_has_src_sel:	true if there is TRI_LED_SRC_SEL register
> + * @channels:	list of PWM channels
> + * @num_channels: number of @channels
> + */
> +struct lpg {
> +	struct device *dev;
> +	struct regmap *map;
> +
> +	struct pwm_chip pwm;
> +
> +	const struct lpg_data *data;
> +
> +	u32 lut_base;
> +	u32 lut_size;
> +	unsigned long *lut_bitmap;
> +
> +	u32 triled_base;
> +	u32 triled_src;
> +	bool triled_has_atc_ctl;
> +	bool triled_has_src_sel;
> +
> +	struct lpg_channel *channels;
> +	unsigned int num_channels;
> +};
> +
> +/**
> + * struct lpg_channel - per channel data
> + * @lpg:	reference to parent lpg
> + * @base:	base address of the PWM channel
> + * @triled_mask: mask in TRILED to enable this channel
> + * @lut_mask:	mask in LUT to start pattern generator for this channel
> + * @in_use:	channel is exposed to LED framework
> + * @color:	color of the LED attached to this channel
> + * @dtest_line:	DTEST line for output, or 0 if disabled
> + * @dtest_value: DTEST line configuration
> + * @pwm_value:	duty (in microseconds) of the generated pulses, overridden by LUT
> + * @enabled:	output enabled?
> + * @period:	period (in nanoseconds) of the generated pulses
> + * @clk:	base frequency of the clock generator
> + * @pre_div:	divider of @clk
> + * @pre_div_exp: exponential divider of @clk
> + * @ramp_enabled: duty cycle is driven by iterating over lookup table
> + * @ramp_ping_pong: reverse through pattern, rather than wrapping to start
> + * @ramp_oneshot: perform only a single pass over the pattern
> + * @ramp_reverse: iterate over pattern backwards
> + * @ramp_tick_ms: length (in milliseconds) of one step in the pattern
> + * @ramp_lo_pause_ms: pause (in milliseconds) before iterating over pattern
> + * @ramp_hi_pause_ms: pause (in milliseconds) after iterating over pattern
> + * @pattern_lo_idx: start index of associated pattern
> + * @pattern_hi_idx: last index of associated pattern
> + */
> +struct lpg_channel {
> +	struct lpg *lpg;
> +
> +	u32 base;
> +	unsigned int triled_mask;
> +	unsigned int lut_mask;
> +
> +	bool in_use;
> +
> +	int color;
> +
> +	u32 dtest_line;
> +	u32 dtest_value;
> +
> +	u16 pwm_value;
> +	bool enabled;
> +
> +	u64 period;
> +	unsigned int clk;
> +	unsigned int pre_div;
> +	unsigned int pre_div_exp;
> +
> +	bool ramp_enabled;
> +	bool ramp_ping_pong;
> +	bool ramp_oneshot;
> +	bool ramp_reverse;
> +	unsigned long ramp_tick_ms;
> +	unsigned long ramp_lo_pause_ms;
> +	unsigned long ramp_hi_pause_ms;
> +
> +	unsigned int pattern_lo_idx;
> +	unsigned int pattern_hi_idx;
> +};
> +
> +/**
> + * struct lpg_led - logical LED object
> + * @lpg:		lpg context reference
> + * @cdev:		LED class device
> + * @mcdev:		Multicolor LED class device
> + * @num_channels:	number of @channels
> + * @channels:		list of channels associated with the LED
> + */
> +struct lpg_led {
> +	struct lpg *lpg;
> +
> +	struct led_classdev cdev;
> +	struct led_classdev_mc mcdev;
> +
> +	unsigned int num_channels;
> +	struct lpg_channel *channels[];
> +};
> +
> +/**
> + * struct lpg_channel_data - per channel initialization data
> + * @base:		base address for PWM channel registers
> + * @triled_mask:	bitmask for controlling this channel in TRILED
> + */
> +struct lpg_channel_data {
> +	unsigned int base;
> +	u8 triled_mask;
> +};
> +
> +/**
> + * struct lpg_data - initialization data
> + * @lut_base:		base address of LUT block
> + * @lut_size:		number of entries in LUT
> + * @triled_base:	base address of TRILED
> + * @triled_has_atc_ctl:	true if there is TRI_LED_ATC_CTL register
> + * @triled_has_src_sel:	true if there is TRI_LED_SRC_SEL register
> + * @pwm_9bit_mask:	bitmask for switching from 6bit to 9bit pwm
> + * @num_channels:	number of channels in LPG
> + * @channels:		list of channel initialization data
> + */
> +struct lpg_data {
> +	unsigned int lut_base;
> +	unsigned int lut_size;
> +	unsigned int triled_base;
> +	bool triled_has_atc_ctl;
> +	bool triled_has_src_sel;
> +	unsigned int pwm_9bit_mask;
> +	int num_channels;
> +	const struct lpg_channel_data *channels;
> +};
> +
> +static int triled_set(struct lpg *lpg, unsigned int mask, unsigned int enable)
> +{
> +	/* Skip if we don't have a triled block */
> +	if (!lpg->triled_base)
> +		return 0;
> +
> +	return regmap_update_bits(lpg->map, lpg->triled_base + TRI_LED_EN_CTL,
> +				  mask, enable);
> +}
> +
> +static int lpg_lut_store(struct lpg *lpg, struct led_pattern *pattern,
> +			 size_t len, unsigned int *lo_idx, unsigned int *hi_idx)
> +{
> +	unsigned int idx;
> +	u16 val;
> +	int i;
> +
> +	/* Hardware does not behave when LO_IDX == HI_IDX */
> +	if (len == 1)
> +		return -EINVAL;
> +
> +	idx = bitmap_find_next_zero_area(lpg->lut_bitmap, lpg->lut_size,
> +					 0, len, 0);
> +	if (idx >= lpg->lut_size)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < len; i++) {
> +		val = pattern[i].brightness;
> +
> +		regmap_bulk_write(lpg->map, lpg->lut_base + LPG_LUT_REG(idx + i),
> +				  &val, sizeof(val));
> +	}
> +
> +	bitmap_set(lpg->lut_bitmap, idx, len);
> +
> +	*lo_idx = idx;
> +	*hi_idx = idx + len - 1;
> +
> +	return 0;
> +}
> +
> +static void lpg_lut_free(struct lpg *lpg, unsigned int lo_idx, unsigned int hi_idx)
> +{
> +	int len;
> +
> +	if (lo_idx == hi_idx)
> +		return;
> +
> +	len = hi_idx - lo_idx + 1;
> +	bitmap_clear(lpg->lut_bitmap, lo_idx, len);
> +}
> +
> +static int lpg_lut_sync(struct lpg *lpg, unsigned int mask)
> +{
> +	return regmap_write(lpg->map, lpg->lut_base + RAMP_CONTROL_REG, mask);
> +}
> +
> +static const unsigned int lpg_clk_rates[] = {1024, 32768, 19200000};
> +static const unsigned int lpg_pre_divs[] = {1, 3, 5, 6};
> +
> +static int lpg_calc_freq(struct lpg_channel *chan, uint64_t period)
> +{
> +	unsigned int clk, best_clk = 0;
> +	unsigned int div, best_div = 0;
> +	unsigned int m, best_m = 0;
> +	unsigned int error;
> +	unsigned int best_err = UINT_MAX;
> +	u64 best_period = 0;
> +
> +	/*
> +	 * The PWM period is determined by:
> +	 *
> +	 *          resolution * pre_div * 2^M
> +	 * period = --------------------------
> +	 *                   refclk
> +	 *
> +	 * With resolution fixed at 2^9 bits, pre_div = {1, 3, 5, 6} and
> +	 * M = [0..7].
> +	 *
> +	 * This allows for periods between 27uS and 384s, as the PWM framework
> +	 * wants a period of equal or lower length than requested, reject
> +	 * anything below 27uS.
> +	 */
> +	if (period <= (u64)NSEC_PER_SEC * LPG_RESOLUTION / 19200000)
> +		return -EINVAL;
> +
> +	/* Limit period to largest possible value, to avoid overflows */
> +	if (period > (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 1024)
> +		period = (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 2014;
> +
> +	/*
> +	 * Search for the pre_div, clk and M by solving the rewritten formula
> +	 * for each clk and pre_div value:
> +	 *
> +	 *                       period * clk
> +	 * M = log2 -------------------------------------
> +	 *           NSEC_PER_SEC * pre_div * resolution
> +	 */
> +	for (clk = 0; clk < ARRAY_SIZE(lpg_clk_rates); clk++) {
> +		u64 nom = period * lpg_clk_rates[clk];
> +
> +		for (div = 0; div < ARRAY_SIZE(lpg_pre_divs); div++) {
> +			u64 denom = (u64)NSEC_PER_SEC * lpg_pre_divs[div] * (1 << 9);
> +			u64 actual;
> +			u64 ratio;
> +
> +			if (nom < denom)
> +				continue;
> +
> +			ratio = div64_u64(nom, denom);
> +			m = ilog2(ratio);
> +			if (m > LPG_MAX_M)
> +				m = LPG_MAX_M;
> +
> +			actual = DIV_ROUND_UP_ULL(denom * (1 << m), lpg_clk_rates[clk]);
> +
> +			error = period - actual;
> +			if (error < best_err) {
> +				best_err = error;
> +
> +				best_div = div;
> +				best_m = m;
> +				best_clk = clk;
> +				best_period = actual;
> +			}
> +		}
> +	}
> +
> +	chan->clk = best_clk;
> +	chan->pre_div = best_div;
> +	chan->pre_div_exp = best_m;
> +	chan->period = best_period;
> +
> +	return 0;
> +}
> +
> +static void lpg_calc_duty(struct lpg_channel *chan, uint64_t duty)
> +{
> +	unsigned int max = LPG_RESOLUTION - 1;
> +	unsigned int val;
> +
> +	val = div64_u64(duty * lpg_clk_rates[chan->clk],
> +			(u64)NSEC_PER_SEC * lpg_pre_divs[chan->pre_div] * (1 << chan->pre_div_exp));
> +
> +	chan->pwm_value = min(val, max);
> +}
> +
> +static void lpg_apply_freq(struct lpg_channel *chan)
> +{
> +	unsigned long val;
> +	struct lpg *lpg = chan->lpg;
> +
> +	if (!chan->enabled)
> +		return;
> +
> +	/* Clock register values are off-by-one from lpg_clk_table */
> +	val = chan->clk + 1;
> +
> +	/* Enable 9bit resolution */
> +	val |= lpg->data->pwm_9bit_mask;
> +
> +	regmap_write(lpg->map, chan->base + LPG_SIZE_CLK_REG, val);
> +
> +	val = chan->pre_div << 5 | chan->pre_div_exp;
> +	regmap_write(lpg->map, chan->base + LPG_PREDIV_CLK_REG, val);
> +}
> +
> +#define LPG_ENABLE_GLITCH_REMOVAL	BIT(5)
> +
> +static void lpg_enable_glitch(struct lpg_channel *chan)
> +{
> +	struct lpg *lpg = chan->lpg;
> +
> +	regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
> +			   LPG_ENABLE_GLITCH_REMOVAL, 0);
> +}
> +
> +static void lpg_disable_glitch(struct lpg_channel *chan)
> +{
> +	struct lpg *lpg = chan->lpg;
> +
> +	regmap_update_bits(lpg->map, chan->base + PWM_TYPE_CONFIG_REG,
> +			   LPG_ENABLE_GLITCH_REMOVAL,
> +			   LPG_ENABLE_GLITCH_REMOVAL);
> +}
> +
> +static void lpg_apply_pwm_value(struct lpg_channel *chan)
> +{
> +	struct lpg *lpg = chan->lpg;
> +	u16 val = chan->pwm_value;
> +
> +	if (!chan->enabled)
> +		return;
> +
> +	regmap_bulk_write(lpg->map, chan->base + PWM_VALUE_REG, &val, sizeof(val));
> +}
> +
> +#define LPG_PATTERN_CONFIG_LO_TO_HI	BIT(4)
> +#define LPG_PATTERN_CONFIG_REPEAT	BIT(3)
> +#define LPG_PATTERN_CONFIG_TOGGLE	BIT(2)
> +#define LPG_PATTERN_CONFIG_PAUSE_HI	BIT(1)
> +#define LPG_PATTERN_CONFIG_PAUSE_LO	BIT(0)
> +
> +static void lpg_apply_lut_control(struct lpg_channel *chan)
> +{
> +	struct lpg *lpg = chan->lpg;
> +	unsigned int hi_pause;
> +	unsigned int lo_pause;
> +	unsigned int conf = 0;
> +	unsigned int step = chan->ramp_tick_ms;
> +	unsigned int lo_idx = chan->pattern_lo_idx;
> +	unsigned int hi_idx = chan->pattern_hi_idx;
> +
> +	if (!chan->ramp_enabled || chan->pattern_lo_idx == chan->pattern_hi_idx)
> +		return;
> +
> +	hi_pause = DIV_ROUND_UP(chan->ramp_hi_pause_ms, step);
> +	lo_pause = DIV_ROUND_UP(chan->ramp_lo_pause_ms, step);
> +
> +	if (!chan->ramp_reverse)
> +		conf |= LPG_PATTERN_CONFIG_LO_TO_HI;
> +	if (!chan->ramp_oneshot)
> +		conf |= LPG_PATTERN_CONFIG_REPEAT;
> +	if (chan->ramp_ping_pong)
> +		conf |= LPG_PATTERN_CONFIG_TOGGLE;
> +	if (chan->ramp_hi_pause_ms)
> +		conf |= LPG_PATTERN_CONFIG_PAUSE_HI;
> +	if (chan->ramp_lo_pause_ms)
> +		conf |= LPG_PATTERN_CONFIG_PAUSE_LO;
> +
> +	regmap_write(lpg->map, chan->base + LPG_PATTERN_CONFIG_REG, conf);
> +	regmap_write(lpg->map, chan->base + LPG_HI_IDX_REG, hi_idx);
> +	regmap_write(lpg->map, chan->base + LPG_LO_IDX_REG, lo_idx);
> +
> +	regmap_write(lpg->map, chan->base + LPG_RAMP_DURATION_REG, step);
> +	regmap_write(lpg->map, chan->base + LPG_HI_PAUSE_REG, hi_pause);
> +	regmap_write(lpg->map, chan->base + LPG_LO_PAUSE_REG, lo_pause);
> +}
> +
> +#define LPG_ENABLE_CONTROL_OUTPUT		BIT(7)
> +#define LPG_ENABLE_CONTROL_BUFFER_TRISTATE	BIT(5)
> +#define LPG_ENABLE_CONTROL_SRC_PWM		BIT(2)
> +#define LPG_ENABLE_CONTROL_RAMP_GEN		BIT(1)
> +
> +static void lpg_apply_control(struct lpg_channel *chan)
> +{
> +	unsigned int ctrl;
> +	struct lpg *lpg = chan->lpg;
> +
> +	ctrl = LPG_ENABLE_CONTROL_BUFFER_TRISTATE;
> +
> +	if (chan->enabled)
> +		ctrl |= LPG_ENABLE_CONTROL_OUTPUT;
> +
> +	if (chan->pattern_lo_idx != chan->pattern_hi_idx)
> +		ctrl |= LPG_ENABLE_CONTROL_RAMP_GEN;
> +	else
> +		ctrl |= LPG_ENABLE_CONTROL_SRC_PWM;
> +
> +	regmap_write(lpg->map, chan->base + PWM_ENABLE_CONTROL_REG, ctrl);
> +
> +	/*
> +	 * Due to LPG hardware bug, in the PWM mode, having enabled PWM,
> +	 * We have to write PWM values one more time.
> +	 */
> +	if (chan->enabled)
> +		lpg_apply_pwm_value(chan);
> +}
> +
> +#define LPG_SYNC_PWM	BIT(0)
> +
> +static void lpg_apply_sync(struct lpg_channel *chan)
> +{
> +	struct lpg *lpg = chan->lpg;
> +
> +	regmap_write(lpg->map, chan->base + PWM_SYNC_REG, LPG_SYNC_PWM);
> +}
> +
> +static int lpg_parse_dtest(struct lpg *lpg)
> +{
> +	struct lpg_channel *chan;
> +	struct device_node *np = lpg->dev->of_node;
> +	int count;
> +	int ret;
> +	int i;
> +
> +	count = of_property_count_u32_elems(np, "qcom,dtest");
> +	if (count == -EINVAL) {
> +		return 0;
> +	} else if (count < 0) {
> +		ret = count;
> +		goto err_malformed;
> +	} else if (count != lpg->data->num_channels * 2) {
> +		dev_err(lpg->dev, "qcom,dtest needs to be %d items\n",
> +			lpg->data->num_channels * 2);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < lpg->data->num_channels; i++) {
> +		chan = &lpg->channels[i];
> +
> +		ret = of_property_read_u32_index(np, "qcom,dtest", i * 2,
> +						 &chan->dtest_line);
> +		if (ret)
> +			goto err_malformed;
> +
> +		ret = of_property_read_u32_index(np, "qcom,dtest", i * 2 + 1,
> +						 &chan->dtest_value);
> +		if (ret)
> +			goto err_malformed;
> +	}
> +
> +	return 0;
> +
> +err_malformed:
> +	dev_err(lpg->dev, "malformed qcom,dtest\n");
> +	return ret;
> +}
> +
> +static void lpg_apply_dtest(struct lpg_channel *chan)
> +{
> +	struct lpg *lpg = chan->lpg;
> +
> +	if (!chan->dtest_line)
> +		return;
> +
> +	regmap_write(lpg->map, chan->base + PWM_SEC_ACCESS_REG, 0xa5);
> +	regmap_write(lpg->map, chan->base + PWM_DTEST_REG(chan->dtest_line),
> +		     chan->dtest_value);
> +}
> +
> +static void lpg_apply(struct lpg_channel *chan)
> +{
> +	lpg_disable_glitch(chan);
> +	lpg_apply_freq(chan);
> +	lpg_apply_pwm_value(chan);
> +	lpg_apply_control(chan);
> +	lpg_apply_sync(chan);
> +	lpg_apply_lut_control(chan);
> +	lpg_enable_glitch(chan);
> +}
> +
> +static void lpg_brightness_set(struct lpg_led *led, struct led_classdev *cdev,
> +			       struct mc_subled *subleds)
> +{
> +	enum led_brightness brightness;
> +	struct lpg_channel *chan;
> +	unsigned int triled_enabled = 0;
> +	unsigned int triled_mask = 0;
> +	unsigned int lut_mask = 0;
> +	unsigned int duty;
> +	struct lpg *lpg = led->lpg;
> +	int i;
> +
> +	for (i = 0; i < led->num_channels; i++) {
> +		chan = led->channels[i];
> +		brightness = subleds[i].brightness;
> +
> +		if (brightness == LED_OFF) {
> +			chan->enabled = false;
> +			chan->ramp_enabled = false;
> +		} else if (chan->pattern_lo_idx != chan->pattern_hi_idx) {
> +			lpg_calc_freq(chan, NSEC_PER_MSEC);
> +
> +			chan->enabled = true;
> +			chan->ramp_enabled = true;
> +
> +			lut_mask |= chan->lut_mask;
> +			triled_enabled |= chan->triled_mask;
> +		} else {
> +			lpg_calc_freq(chan, NSEC_PER_MSEC);
> +
> +			duty = div_u64(brightness * chan->period, cdev->max_brightness);
> +			lpg_calc_duty(chan, duty);
> +			chan->enabled = true;
> +			chan->ramp_enabled = false;
> +
> +			triled_enabled |= chan->triled_mask;
> +		}
> +
> +		triled_mask |= chan->triled_mask;
> +
> +		lpg_apply(chan);
> +	}
> +
> +	/* Toggle triled lines */
> +	if (triled_mask)
> +		triled_set(lpg, triled_mask, triled_enabled);
> +
> +	/* Trigger start of ramp generator(s) */
> +	if (lut_mask)
> +		lpg_lut_sync(lpg, lut_mask);
> +}
> +
> +static void lpg_brightness_single_set(struct led_classdev *cdev,
> +				      enum led_brightness value)
> +{
> +	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> +	struct mc_subled info;
> +
> +	info.brightness = value;
> +	lpg_brightness_set(led, cdev, &info);
> +}
> +
> +static void lpg_brightness_mc_set(struct led_classdev *cdev,
> +				  enum led_brightness value)
> +{
> +	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> +	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> +
> +	led_mc_calc_color_components(mc, value);
> +	lpg_brightness_set(led, cdev, mc->subled_info);
> +}
> +
> +static int lpg_blink_set(struct lpg_led *led,
> +			 unsigned long *delay_on, unsigned long *delay_off)
> +{
> +	struct lpg_channel *chan;
> +	unsigned int period;
> +	unsigned int triled_mask = 0;
> +	struct lpg *lpg = led->lpg;
> +	u64 duty;
> +	int i;
> +
> +	if (!*delay_on && !*delay_off) {
> +		*delay_on = 500;
> +		*delay_off = 500;
> +	}
> +
> +	duty = *delay_on * NSEC_PER_MSEC;
> +	period = (*delay_on + *delay_off) * NSEC_PER_MSEC;
> +
> +	for (i = 0; i < led->num_channels; i++) {
> +		chan = led->channels[i];
> +
> +		lpg_calc_freq(chan, period);
> +		lpg_calc_duty(chan, duty);
> +
> +		chan->enabled = true;
> +		chan->ramp_enabled = false;
> +
> +		triled_mask |= chan->triled_mask;
> +
> +		lpg_apply(chan);
> +	}
> +
> +	/* Enable triled lines */
> +	triled_set(lpg, triled_mask, triled_mask);
> +
> +	chan = led->channels[0];
> +	duty = div_u64(chan->pwm_value * chan->period, LPG_RESOLUTION);
> +	*delay_on = div_u64(duty, NSEC_PER_MSEC);
> +	*delay_off = div_u64(chan->period - duty, NSEC_PER_MSEC);
> +
> +	return 0;
> +}
> +
> +static int lpg_blink_single_set(struct led_classdev *cdev,
> +				unsigned long *delay_on, unsigned long *delay_off)
> +{
> +	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> +
> +	return lpg_blink_set(led, delay_on, delay_off);
> +}
> +
> +static int lpg_blink_mc_set(struct led_classdev *cdev,
> +			    unsigned long *delay_on, unsigned long *delay_off)
> +{
> +	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> +	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> +
> +	return lpg_blink_set(led, delay_on, delay_off);
> +}
> +
> +static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *pattern,
> +			   u32 len, int repeat)
> +{
> +	struct lpg_channel *chan;
> +	struct lpg *lpg = led->lpg;
> +	unsigned int hi_pause;
> +	unsigned int lo_pause;
> +	unsigned int lo_idx;
> +	unsigned int hi_idx;
> +	bool ping_pong = true;
> +	int brightness_a;
> +	int brightness_b;
> +	int ret;
> +	int i;
> +
> +	/* Only support oneshot or indefinite loops, due to limited pattern space */
> +	if (repeat != -1 && repeat != 1)
> +		return -EINVAL;
> +
> +	/*
> +	 * The LPG plays patterns with at a fixed pace, a "low pause" can be
> +	 * performed before the pattern and a "high pause" after. In order to
> +	 * save space the pattern can be played in "ping pong" mode, in which
> +	 * the pattern is first played forward, then "high pause" is applied,
> +	 * then the pattern is played backwards and finally the "low pause" is
> +	 * applied.
> +	 *
> +	 * The delta_t of the first entry is used to determine the pace of the
> +	 * pattern.
> +	 *
> +	 * If the specified pattern is a palindrome the ping pong mode is
> +	 * enabled. In this scenario the delta_t of the last entry determines
> +	 * the "low pause" time and the delta_t of the middle entry (i.e. the
> +	 * last in the programmed pattern) determines the "high pause". If the
> +	 * pattern consists of an odd number of values, no "high pause" is
> +	 * used.
> +	 *
> +	 * When ping pong mode is not selected, the delta_t of the last entry
> +	 * is used as "high pause". No "low pause" is used.
> +	 *
> +	 * delta_t of any other members of the pattern is ignored.
> +	 */
> +
> +	/* Detect palindromes and use "ping pong" to reduce LUT usage */
> +	for (i = 0; i < len / 2; i++) {
> +		brightness_a = pattern[i].brightness;
> +		brightness_b = pattern[len - i - 1].brightness;
> +
> +		if (brightness_a != brightness_b) {
> +			ping_pong = false;
> +			break;
> +		}
> +	}
> +
> +	if (ping_pong) {
> +		if (len % 2)
> +			hi_pause = 0;
> +		else
> +			hi_pause = pattern[(len + 1) / 2].delta_t;
> +		lo_pause = pattern[len - 1].delta_t;
> +
> +		len = (len + 1) / 2;
> +	} else {
> +		hi_pause = pattern[len - 1].delta_t;
> +		lo_pause = 0;
> +	}
> +
> +	ret = lpg_lut_store(lpg, pattern, len, &lo_idx, &hi_idx);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < led->num_channels; i++) {
> +		chan = led->channels[i];
> +
> +		chan->ramp_tick_ms = pattern[0].delta_t;
> +		chan->ramp_ping_pong = ping_pong;
> +		chan->ramp_oneshot = repeat != -1;
> +
> +		chan->ramp_lo_pause_ms = lo_pause;
> +		chan->ramp_hi_pause_ms = hi_pause;
> +
> +		chan->pattern_lo_idx = lo_idx;
> +		chan->pattern_hi_idx = hi_idx;
> +	}
> +
> +	return 0;
> +}
> +
> +static int lpg_pattern_single_set(struct led_classdev *cdev,
> +				  struct led_pattern *pattern, u32 len,
> +				  int repeat)
> +{
> +	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> +	int ret;
> +
> +	ret = lpg_pattern_set(led, pattern, len, repeat);
> +	if (ret < 0)
> +		return ret;
> +
> +	lpg_brightness_single_set(cdev, LED_FULL);
> +
> +	return 0;
> +}
> +
> +static int lpg_pattern_mc_set(struct led_classdev *cdev,
> +			      struct led_pattern *pattern, u32 len,
> +			      int repeat)
> +{
> +	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> +	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> +	int ret;
> +
> +	ret = lpg_pattern_set(led, pattern, len, repeat);
> +	if (ret < 0)
> +		return ret;
> +
> +	led_mc_calc_color_components(mc, LED_FULL);
> +	lpg_brightness_set(led, cdev, mc->subled_info);
> +
> +	return 0;
> +}
> +
> +static int lpg_pattern_clear(struct lpg_led *led)
> +{
> +	struct lpg_channel *chan;
> +	struct lpg *lpg = led->lpg;
> +	int i;
> +
> +	chan = led->channels[0];
> +	lpg_lut_free(lpg, chan->pattern_lo_idx, chan->pattern_hi_idx);
> +
> +	for (i = 0; i < led->num_channels; i++) {
> +		chan = led->channels[i];
> +		chan->pattern_lo_idx = 0;
> +		chan->pattern_hi_idx = 0;
> +	}
> +
> +	return 0;
> +}
> +
> +static int lpg_pattern_single_clear(struct led_classdev *cdev)
> +{
> +	struct lpg_led *led = container_of(cdev, struct lpg_led, cdev);
> +
> +	return lpg_pattern_clear(led);
> +}
> +
> +static int lpg_pattern_mc_clear(struct led_classdev *cdev)
> +{
> +	struct led_classdev_mc *mc = lcdev_to_mccdev(cdev);
> +	struct lpg_led *led = container_of(mc, struct lpg_led, mcdev);
> +
> +	return lpg_pattern_clear(led);
> +}
> +
> +static int lpg_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
> +{
> +	struct lpg *lpg = container_of(chip, struct lpg, pwm);
> +	struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
> +
> +	return chan->in_use ? -EBUSY : 0;
> +}
> +
> +/*
> + * Limitations:
> + * - Updating both duty and period is not done atomically, so the output signal
> + *   will momentarily be a mix of the settings.
> + */
> +static int lpg_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
> +			 const struct pwm_state *state)
> +{
> +	struct lpg *lpg = container_of(chip, struct lpg, pwm);
> +	struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
> +	int ret;
> +
> +	if (state->polarity != PWM_POLARITY_NORMAL)
> +		return -EINVAL;
> +
> +	ret = lpg_calc_freq(chan, state->period);
> +	if (ret < 0)
> +		return ret;
> +
> +	lpg_calc_duty(chan, state->duty_cycle);
> +	chan->enabled = state->enabled;
> +
> +	lpg_apply(chan);
> +
> +	triled_set(lpg, chan->triled_mask, chan->enabled ? chan->triled_mask : 0);
> +
> +	return 0;
> +}
> +
> +static void lpg_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
> +			      struct pwm_state *state)
> +{
> +	struct lpg *lpg = container_of(chip, struct lpg, pwm);
> +	struct lpg_channel *chan = &lpg->channels[pwm->hwpwm];
> +	u64 duty = DIV_ROUND_UP_ULL(chan->pwm_value * chan->period, LPG_RESOLUTION - 1);
> +
> +	state->period = chan->period;
> +	state->duty_cycle = duty;
> +	state->polarity = PWM_POLARITY_NORMAL;
> +	state->enabled = chan->enabled;
> +}
> +
> +static const struct pwm_ops lpg_pwm_ops = {
> +	.request = lpg_pwm_request,
> +	.apply = lpg_pwm_apply,
> +	.get_state = lpg_pwm_get_state,
> +	.owner = THIS_MODULE,
> +};
> +
> +static int lpg_add_pwm(struct lpg *lpg)
> +{
> +	int ret;
> +
> +	lpg->pwm.base = -1;
> +	lpg->pwm.dev = lpg->dev;
> +	lpg->pwm.npwm = lpg->num_channels;
> +	lpg->pwm.ops = &lpg_pwm_ops;
> +
> +	ret = pwmchip_add(&lpg->pwm);
> +	if (ret)
> +		dev_err(lpg->dev, "failed to add PWM chip: ret %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static int lpg_parse_channel(struct lpg *lpg, struct device_node *np,
> +			     struct lpg_channel **channel)
> +{
> +	struct lpg_channel *chan;
> +	u32 color = LED_COLOR_ID_GREEN;
> +	u32 reg;
> +	int ret;
> +
> +	ret = of_property_read_u32(np, "reg", &reg);
> +	if (ret || !reg || reg > lpg->num_channels) {
> +		dev_err(lpg->dev, "invalid \"reg\" of %pOFn\n", np);
> +		return -EINVAL;
> +	}
> +
> +	chan = &lpg->channels[reg - 1];
> +	chan->in_use = true;
> +
> +	ret = of_property_read_u32(np, "color", &color);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
> +		return ret;
> +	}
> +
> +	chan->color = color;
> +
> +	*channel = chan;
> +
> +	return 0;
> +}
> +
> +static int lpg_add_led(struct lpg *lpg, struct device_node *np)
> +{
> +	struct led_init_data init_data = {};
> +	struct led_classdev *cdev;
> +	struct device_node *child;
> +	struct mc_subled *info;
> +	struct lpg_led *led;
> +	const char *state;
> +	int num_channels;
> +	u32 color = 0;
> +	int ret;
> +	int i;
> +
> +	ret = of_property_read_u32(np, "color", &color);
> +	if (ret < 0 && ret != -EINVAL) {
> +		dev_err(lpg->dev, "failed to parse \"color\" of %pOF\n", np);
> +		return ret;
> +	}
> +
> +	if (color == LED_COLOR_ID_RGB)
> +		num_channels = of_get_available_child_count(np);
> +	else
> +		num_channels = 1;
> +
> +	led = devm_kzalloc(lpg->dev, struct_size(led, channels, num_channels), GFP_KERNEL);
> +	if (!led)
> +		return -ENOMEM;
> +
> +	led->lpg = lpg;
> +	led->num_channels = num_channels;
> +
> +	if (color == LED_COLOR_ID_RGB) {
> +		info = devm_kcalloc(lpg->dev, num_channels, sizeof(*info), GFP_KERNEL);
> +		if (!info)
> +			return -ENOMEM;
> +		i = 0;
> +		for_each_available_child_of_node(np, child) {
> +			ret = lpg_parse_channel(lpg, child, &led->channels[i]);
> +			if (ret < 0)
> +				return ret;
> +
> +			info[i].color_index = led->channels[i]->color;
> +			info[i].intensity = LED_FULL;
> +			i++;
> +		}
> +
> +		led->mcdev.subled_info = info;
> +		led->mcdev.num_colors = num_channels;
> +
> +		cdev = &led->mcdev.led_cdev;
> +		cdev->brightness_set = lpg_brightness_mc_set;
> +		cdev->blink_set = lpg_blink_mc_set;
> +
> +		/* Register pattern accessors only if we have a LUT block */
> +		if (lpg->lut_base) {
> +			cdev->pattern_set = lpg_pattern_mc_set;
> +			cdev->pattern_clear = lpg_pattern_mc_clear;
> +		}
> +	} else {
> +		ret = lpg_parse_channel(lpg, np, &led->channels[0]);
> +		if (ret < 0)
> +			return ret;
> +
> +		cdev = &led->cdev;
> +		cdev->brightness_set = lpg_brightness_single_set;
> +		cdev->blink_set = lpg_blink_single_set;
> +
> +		/* Register pattern accessors only if we have a LUT block */
> +		if (lpg->lut_base) {
> +			cdev->pattern_set = lpg_pattern_single_set;
> +			cdev->pattern_clear = lpg_pattern_single_clear;
> +		}
> +	}
> +
> +	cdev->default_trigger = of_get_property(np, "linux,default-trigger", NULL);
> +	cdev->max_brightness = 255;
> +
> +	if (!of_property_read_string(np, "default-state", &state) &&
> +	    !strcmp(state, "on"))
> +		cdev->brightness = LED_FULL;
> +	else
> +		cdev->brightness = LED_OFF;
> +
> +	cdev->brightness_set(cdev, cdev->brightness);
> +
> +	init_data.fwnode = of_fwnode_handle(np);
> +
> +	if (color == LED_COLOR_ID_RGB)
> +		ret = devm_led_classdev_multicolor_register_ext(lpg->dev, &led->mcdev, &init_data);
> +	else
> +		ret = devm_led_classdev_register_ext(lpg->dev, &led->cdev, &init_data);
> +	if (ret)
> +		dev_err(lpg->dev, "unable to register %s\n", cdev->name);
> +
> +	return ret;
> +}
> +
> +static int lpg_init_channels(struct lpg *lpg)
> +{
> +	const struct lpg_data *data = lpg->data;
> +	int i;
> +
> +	lpg->num_channels = data->num_channels;
> +	lpg->channels = devm_kcalloc(lpg->dev, data->num_channels,
> +				     sizeof(struct lpg_channel), GFP_KERNEL);
> +	if (!lpg->channels)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < data->num_channels; i++) {
> +		lpg->channels[i].lpg = lpg;
> +		lpg->channels[i].base = data->channels[i].base;
> +		lpg->channels[i].triled_mask = data->channels[i].triled_mask;
> +		lpg->channels[i].lut_mask = BIT(i);
> +	}
> +
> +	return 0;
> +}
> +
> +static int lpg_init_triled(struct lpg *lpg)
> +{
> +	struct device_node *np = lpg->dev->of_node;
> +	int ret;
> +
> +	/* Skip initialization if we don't have a triled block */
> +	if (!lpg->data->triled_base)
> +		return 0;
> +
> +	lpg->triled_base = lpg->data->triled_base;
> +	lpg->triled_has_atc_ctl = lpg->data->triled_has_atc_ctl;
> +	lpg->triled_has_src_sel = lpg->data->triled_has_src_sel;
> +
> +	if (lpg->triled_has_src_sel) {
> +		ret = of_property_read_u32(np, "qcom,power-source", &lpg->triled_src);
> +		if (ret || lpg->triled_src == 2 || lpg->triled_src > 3) {
> +			dev_err(lpg->dev, "invalid power source\n");
> +			return -EINVAL;
> +		}
> +	}
> +
> +	/* Disable automatic trickle charge LED */
> +	if (lpg->triled_has_atc_ctl)
> +		regmap_write(lpg->map, lpg->triled_base + TRI_LED_ATC_CTL, 0);
> +
> +	/* Configure power source */
> +	if (lpg->triled_has_src_sel)
> +		regmap_write(lpg->map, lpg->triled_base + TRI_LED_SRC_SEL, lpg->triled_src);
> +
> +	/* Default all outputs to off */
> +	regmap_write(lpg->map, lpg->triled_base + TRI_LED_EN_CTL, 0);
> +
> +	return 0;
> +}
> +
> +static int lpg_init_lut(struct lpg *lpg)
> +{
> +	const struct lpg_data *data = lpg->data;
> +	size_t bitmap_size;
> +
> +	if (!data->lut_base)
> +		return 0;
> +
> +	lpg->lut_base = data->lut_base;
> +	lpg->lut_size = data->lut_size;
> +
> +	bitmap_size = BITS_TO_BYTES(lpg->lut_size);
> +	lpg->lut_bitmap = devm_kzalloc(lpg->dev, bitmap_size, GFP_KERNEL);
> +	if (!lpg->lut_bitmap)
> +		return -ENOMEM;
> +
> +	return 0;
> +}
> +
> +static int lpg_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np;
> +	struct lpg *lpg;
> +	int ret;
> +	int i;
> +
> +	lpg = devm_kzalloc(&pdev->dev, sizeof(*lpg), GFP_KERNEL);
> +	if (!lpg)
> +		return -ENOMEM;
> +
> +	lpg->data = of_device_get_match_data(&pdev->dev);
> +	if (!lpg->data)
> +		return -EINVAL;
> +
> +	platform_set_drvdata(pdev, lpg);
> +
> +	lpg->dev = &pdev->dev;
> +
> +	lpg->map = dev_get_regmap(pdev->dev.parent, NULL);
> +	if (!lpg->map) {
> +		dev_err(&pdev->dev, "parent regmap unavailable\n");
> +		return -ENXIO;
> +	}
> +
> +	ret = lpg_init_channels(lpg);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = lpg_parse_dtest(lpg);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = lpg_init_triled(lpg);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = lpg_init_lut(lpg);
> +	if (ret < 0)
> +		return ret;
> +
> +	for_each_available_child_of_node(pdev->dev.of_node, np) {
> +		ret = lpg_add_led(lpg, np);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	for (i = 0; i < lpg->num_channels; i++)
> +		lpg_apply_dtest(&lpg->channels[i]);
> +
> +	return lpg_add_pwm(lpg);
> +}
> +
> +static int lpg_remove(struct platform_device *pdev)
> +{
> +	struct lpg *lpg = platform_get_drvdata(pdev);
> +
> +	pwmchip_remove(&lpg->pwm);
> +
> +	return 0;
> +}
> +
> +static const struct lpg_data pm8916_pwm_data = {
> +	.pwm_9bit_mask = BIT(2),
> +
> +	.num_channels = 1,
> +	.channels = (const struct lpg_channel_data[]) {
> +		{ .base = 0xbc00 },
> +	},
> +};
> +
> +static const struct lpg_data pm8941_lpg_data = {
> +	.lut_base = 0xb000,
> +	.lut_size = 64,
> +
> +	.triled_base = 0xd000,
> +	.triled_has_atc_ctl = true,
> +	.triled_has_src_sel = true,
> +
> +	.pwm_9bit_mask = 3 << 4,
> +
> +	.num_channels = 8,
> +	.channels = (const struct lpg_channel_data[]) {
> +		{ .base = 0xb100 },
> +		{ .base = 0xb200 },
> +		{ .base = 0xb300 },
> +		{ .base = 0xb400 },
> +		{ .base = 0xb500, .triled_mask = BIT(5) },
> +		{ .base = 0xb600, .triled_mask = BIT(6) },
> +		{ .base = 0xb700, .triled_mask = BIT(7) },
> +		{ .base = 0xb800 },
> +	},
> +};
> +
> +static const struct lpg_data pm8994_lpg_data = {
> +	.lut_base = 0xb000,
> +	.lut_size = 64,
> +
> +	.pwm_9bit_mask = 3 << 4,
> +
> +	.num_channels = 6,
> +	.channels = (const struct lpg_channel_data[]) {
> +		{ .base = 0xb100 },
> +		{ .base = 0xb200 },
> +		{ .base = 0xb300 },
> +		{ .base = 0xb400 },
> +		{ .base = 0xb500 },
> +		{ .base = 0xb600 },
> +	},
> +};
> +
> +static const struct lpg_data pmi8994_lpg_data = {
> +	.lut_base = 0xb000,
> +	.lut_size = 24,
> +
> +	.triled_base = 0xd000,
> +	.triled_has_atc_ctl = true,
> +	.triled_has_src_sel = true,
> +
> +	.pwm_9bit_mask = BIT(4),
> +
> +	.num_channels = 4,
> +	.channels = (const struct lpg_channel_data[]) {
> +		{ .base = 0xb100, .triled_mask = BIT(5) },
> +		{ .base = 0xb200, .triled_mask = BIT(6) },
> +		{ .base = 0xb300, .triled_mask = BIT(7) },
> +		{ .base = 0xb400 },
> +	},
> +};
> +
> +static const struct lpg_data pmi8998_lpg_data = {
> +	.lut_base = 0xb000,
> +	.lut_size = 49,
> +
> +	.triled_base = 0xd000,
> +
> +	.pwm_9bit_mask = BIT(4),
> +
> +	.num_channels = 6,
> +	.channels = (const struct lpg_channel_data[]) {
> +		{ .base = 0xb100 },
> +		{ .base = 0xb200 },
> +		{ .base = 0xb300, .triled_mask = BIT(5) },
> +		{ .base = 0xb400, .triled_mask = BIT(6) },
> +		{ .base = 0xb500, .triled_mask = BIT(7) },
> +		{ .base = 0xb600 },
> +	},
> +};
> +
> +static const struct lpg_data pm8150b_lpg_data = {
> +	.lut_base = 0xb000,
> +	.lut_size = 24,
> +
> +	.triled_base = 0xd000,
> +
> +	.pwm_9bit_mask = BIT(4),
> +
> +	.num_channels = 2,
> +	.channels = (const struct lpg_channel_data[]) {
> +		{ .base = 0xb100, .triled_mask = BIT(7) },
> +		{ .base = 0xb200, .triled_mask = BIT(6) },
> +	},
> +};
> +
> +static const struct lpg_data pm8150l_lpg_data = {
> +	.lut_base = 0xb000,
> +	.lut_size = 48,
> +
> +	.triled_base = 0xd000,
> +
> +	.pwm_9bit_mask = BIT(4),
> +
> +	.num_channels = 5,
> +	.channels = (const struct lpg_channel_data[]) {
> +		{ .base = 0xb100, .triled_mask = BIT(7) },
> +		{ .base = 0xb200, .triled_mask = BIT(6) },
> +		{ .base = 0xb300, .triled_mask = BIT(5) },
> +		{ .base = 0xbc00 },
> +		{ .base = 0xbd00 },
> +
> +	},
> +};
> +
> +static const struct of_device_id lpg_of_table[] = {
> +	{ .compatible = "qcom,pm8150b-lpg", .data = &pm8150b_lpg_data },
> +	{ .compatible = "qcom,pm8150l-lpg", .data = &pm8150l_lpg_data },
> +	{ .compatible = "qcom,pm8916-pwm", .data = &pm8916_pwm_data },
> +	{ .compatible = "qcom,pm8941-lpg", .data = &pm8941_lpg_data },
> +	{ .compatible = "qcom,pm8994-lpg", .data = &pm8994_lpg_data },
> +	{ .compatible = "qcom,pmi8994-lpg", .data = &pmi8994_lpg_data },
> +	{ .compatible = "qcom,pmi8998-lpg", .data = &pmi8998_lpg_data },
> +	{ .compatible = "qcom,pmc8180c-lpg", .data = &pm8150l_lpg_data },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, lpg_of_table);
> +
> +static struct platform_driver lpg_driver = {
> +	.probe = lpg_probe,
> +	.remove = lpg_remove,
> +	.driver = {
> +		.name = "qcom-spmi-lpg",
> +		.of_match_table = lpg_of_table,
> +	},
> +};
> +module_platform_driver(lpg_driver);
> +
> +MODULE_DESCRIPTION("Qualcomm LPG LED driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 2.29.2
> 

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Subbaraman Narayanamurthy]

Hi Bjorn,

> +#define LPG_RESOLUTION		512

Just a thought. Having this fixed to 9-bit resolution would require a lot of code churn if this driver ends up supporting higher resolution PWM later. Would it be possible to have this as a parameter in "struct lpg_channel" ?

> +static const unsigned int lpg_clk_rates[] = {1024, 32768, 19200000};
> +static const unsigned int lpg_pre_divs[] = {1, 3, 5, 6};
> +
> +static int lpg_calc_freq(struct lpg_channel *chan, uint64_t period)
> +{
> +	unsigned int clk, best_clk = 0;
> +	unsigned int div, best_div = 0;
> +	unsigned int m, best_m = 0;
> +	unsigned int error;
> +	unsigned int best_err = UINT_MAX;
> +	u64 best_period = 0;
> +
> +	/*
> +	 * The PWM period is determined by:
> +	 *
> +	 *          resolution * pre_div * 2^M
> +	 * period = --------------------------
> +	 *                   refclk
> +	 *
> +	 * With resolution fixed at 2^9 bits, pre_div = {1, 3, 5, 6} and
> +	 * M = [0..7].
> +	 *
> +	 * This allows for periods between 27uS and 384s, as the PWM framework
> +	 * wants a period of equal or lower length than requested, reject
> +	 * anything below 27uS.
> +	 */
> +	if (period <= (u64)NSEC_PER_SEC * LPG_RESOLUTION / 19200000)
> +		return -EINVAL;
> +
> +	/* Limit period to largest possible value, to avoid overflows */
> +	if (period > (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 1024)
> +		period = (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 2014;

s/2014/1024 ?

Thanks,
Subbaraman

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Bjorn Andersson]

On Mon 25 Oct 17:37 PDT 2021, Subbaraman Narayanamurthy wrote:

> Hi Bjorn,
> 
> > +#define LPG_RESOLUTION		512
> 
> Just a thought. Having this fixed to 9-bit resolution would require a
> lot of code churn if this driver ends up supporting higher resolution
> PWM later. Would it be possible to have this as a parameter in "struct
> lpg_channel" ?
> 

In earlier revisions I had support for picking 6 vs 9 bit resolution
dynamically, but looked ahead and iirc saw that we only support 9 bit
for the now current generation (it's been a while, so I might
misremember).

The end result was that I ripped that out to simplify the code from the
various heuristics that had been bolted on during the generations.


People seem okay with this version and it meets the need of a large
number of PMICs and use cases, so I would prefer that we land this and
then evolve it based on requirements I haven't yet seen.

> > +static const unsigned int lpg_clk_rates[] = {1024, 32768, 19200000};
> > +static const unsigned int lpg_pre_divs[] = {1, 3, 5, 6};
> > +
> > +static int lpg_calc_freq(struct lpg_channel *chan, uint64_t period)
> > +{
> > +	unsigned int clk, best_clk = 0;
> > +	unsigned int div, best_div = 0;
> > +	unsigned int m, best_m = 0;
> > +	unsigned int error;
> > +	unsigned int best_err = UINT_MAX;
> > +	u64 best_period = 0;
> > +
> > +	/*
> > +	 * The PWM period is determined by:
> > +	 *
> > +	 *          resolution * pre_div * 2^M
> > +	 * period = --------------------------
> > +	 *                   refclk
> > +	 *
> > +	 * With resolution fixed at 2^9 bits, pre_div = {1, 3, 5, 6} and
> > +	 * M = [0..7].
> > +	 *
> > +	 * This allows for periods between 27uS and 384s, as the PWM framework
> > +	 * wants a period of equal or lower length than requested, reject
> > +	 * anything below 27uS.
> > +	 */
> > +	if (period <= (u64)NSEC_PER_SEC * LPG_RESOLUTION / 19200000)
> > +		return -EINVAL;
> > +
> > +	/* Limit period to largest possible value, to avoid overflows */
> > +	if (period > (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 1024)
> > +		period = (u64)NSEC_PER_SEC * LPG_RESOLUTION * 6 * (1 << LPG_MAX_M) / 2014;
> 
> s/2014/1024 ?
> 

Now that's an interesting typo... I will correct this and submit v11.

Thanks,
Bjorn

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Marijn Suijten]

Hi Bjorn,

On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> 
> > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > with their output being routed to various other components, such as
> > current sinks or GPIOs.
> > 
> > Each LPG instance can operate on fixed parameters or based on a shared
> > lookup-table, altering the duty cycle over time. This provides the means
> > for hardware assisted transitions of LED brightness.
> > 
> > A typical use case for the fixed parameter mode is to drive a PWM
> > backlight control signal, the driver therefor allows each LPG instance
> > to be exposed to the kernel either through the LED framework or the PWM
> > framework.
> > 
> > A typical use case for the LED configuration is to drive RGB LEDs in
> > smartphones etc, for which the driver support multiple channels to be
> > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > generators will be synchronized, to allow for multi-color patterns.
> > 
> > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > ---
> 
> Any feedback on this?

I asked in #linux-msm whether anything is wrong with the patterns,
since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
pattern that's supposed to stay on for 1s and off for 1s:

    echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern

It however seems to be broken in the same way on an older version now
(this might be v9 or v8) which I don't remember to be the case.  Can you
double-check if this is all working fine on your side?  If so, I'll have
to find some time to debug it on my end.

Thanks!
- Marijn

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Marijn Suijten]

On 2021-10-27 23:19:30, Marijn Suijten wrote:
> Hi Bjorn,
> 
> On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> > On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> > 
> > > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > > with their output being routed to various other components, such as
> > > current sinks or GPIOs.
> > > 
> > > Each LPG instance can operate on fixed parameters or based on a shared
> > > lookup-table, altering the duty cycle over time. This provides the means
> > > for hardware assisted transitions of LED brightness.
> > > 
> > > A typical use case for the fixed parameter mode is to drive a PWM
> > > backlight control signal, the driver therefor allows each LPG instance
> > > to be exposed to the kernel either through the LED framework or the PWM
> > > framework.
> > > 
> > > A typical use case for the LED configuration is to drive RGB LEDs in
> > > smartphones etc, for which the driver support multiple channels to be
> > > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > > generators will be synchronized, to allow for multi-color patterns.
> > > 
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > ---
> > 
> > Any feedback on this?
> 
> I asked in #linux-msm whether anything is wrong with the patterns,
> since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
> pattern that's supposed to stay on for 1s and off for 1s:
> 
>     echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern
> 
> It however seems to be broken in the same way on an older version now
> (this might be v9 or v8) which I don't remember to be the case.  Can you
> double-check if this is all working fine on your side?  If so, I'll have
> to find some time to debug it on my end.
> 
> Thanks!
> - Marijn

Another thing I just ran into: on both patch revisions the colors are
flipped.  multi_index reports "red green glue", but the values written
to multi_intensity correspond to "blue green red" instead.  Is it the
same on your side?

- Marijn

Re: [PATCH v10 1/2] dt-bindings: leds: Add Qualcomm Light Pulse Generator binding

[Stephen Boyd]

Quoting Bjorn Andersson (2021-10-09 21:39:11)
> This adds the binding document describing the three hardware blocks
> related to the Light Pulse Generator found in a wide range of Qualcomm
> PMICs.
> 
> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> ---

Reviewed-by: Stephen Boyd <swboyd@chromium.org>

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Bjorn Andersson]

On Wed 27 Oct 16:19 CDT 2021, Marijn Suijten wrote:

> Hi Bjorn,
> 
> On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> > On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> > 
> > > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > > with their output being routed to various other components, such as
> > > current sinks or GPIOs.
> > > 
> > > Each LPG instance can operate on fixed parameters or based on a shared
> > > lookup-table, altering the duty cycle over time. This provides the means
> > > for hardware assisted transitions of LED brightness.
> > > 
> > > A typical use case for the fixed parameter mode is to drive a PWM
> > > backlight control signal, the driver therefor allows each LPG instance
> > > to be exposed to the kernel either through the LED framework or the PWM
> > > framework.
> > > 
> > > A typical use case for the LED configuration is to drive RGB LEDs in
> > > smartphones etc, for which the driver support multiple channels to be
> > > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > > generators will be synchronized, to allow for multi-color patterns.
> > > 
> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > ---
> > 
> > Any feedback on this?
> 
> I asked in #linux-msm whether anything is wrong with the patterns,
> since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
> pattern that's supposed to stay on for 1s and off for 1s:
> 
>     echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern
> 
> It however seems to be broken in the same way on an older version now
> (this might be v9 or v8) which I don't remember to be the case.  Can you
> double-check if this is all working fine on your side?  If so, I'll have
> to find some time to debug it on my end.
> 

I had missed the fact that LPG_RAMP_DURATION_REG is two registers for
msg and lsb, for a total of 9 bits of duration. So what you saw was
probably ticking at 232ms.

Note though that the pattern uses the last time as "high pause", so I
expect that you should have seen 232 ms of off, followed by 464ms of
light.

I've fixed this for v11, both rejecting invalid input and writing out
all 9 bits.

Thanks for spotting this!
Bjorn

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Bjorn Andersson]

On Wed 27 Oct 16:27 CDT 2021, Marijn Suijten wrote:

> On 2021-10-27 23:19:30, Marijn Suijten wrote:
> > Hi Bjorn,
> > 
> > On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> > > On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> > > 
> > > > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > > > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > > > with their output being routed to various other components, such as
> > > > current sinks or GPIOs.
> > > > 
> > > > Each LPG instance can operate on fixed parameters or based on a shared
> > > > lookup-table, altering the duty cycle over time. This provides the means
> > > > for hardware assisted transitions of LED brightness.
> > > > 
> > > > A typical use case for the fixed parameter mode is to drive a PWM
> > > > backlight control signal, the driver therefor allows each LPG instance
> > > > to be exposed to the kernel either through the LED framework or the PWM
> > > > framework.
> > > > 
> > > > A typical use case for the LED configuration is to drive RGB LEDs in
> > > > smartphones etc, for which the driver support multiple channels to be
> > > > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > > > generators will be synchronized, to allow for multi-color patterns.
> > > > 
> > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > ---
> > > 
> > > Any feedback on this?
> > 
> > I asked in #linux-msm whether anything is wrong with the patterns,
> > since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
> > pattern that's supposed to stay on for 1s and off for 1s:
> > 
> >     echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern
> > 
> > It however seems to be broken in the same way on an older version now
> > (this might be v9 or v8) which I don't remember to be the case.  Can you
> > double-check if this is all working fine on your side?  If so, I'll have
> > to find some time to debug it on my end.
> > 
> > Thanks!
> > - Marijn
> 
> Another thing I just ran into: on both patch revisions the colors are
> flipped.  multi_index reports "red green glue", but the values written
> to multi_intensity correspond to "blue green red" instead.  Is it the
> same on your side?
> 

I booted one of my 8974 devices with RGB LED and the colors matches my
expectations. Can you confirm that your mapping in the DT node is
correct?

E.g. with pm8941 the mapping should be "backwards":

lpg {
    ...;
    rgb-led {
        color = <LED_COLOR_ID_RGB>;
        function = LED_FUNCTION_STATUS;

        #address-cells = <1>;
        #size-cells = <0>;

        led@1 {
            reg = <7>;
            color = <LED_COLOR_ID_RED>;
        };

        led@2 {
            reg = <6>;
            color = <LED_COLOR_ID_GREEN>;
        };

        led@3 {
            reg = <5>;
            color = <LED_COLOR_ID_BLUE>;
        };
};

Regards,
Bjorn

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Marijn Suijten]

On 2022-01-28 18:53:24, Bjorn Andersson wrote:
> On Wed 27 Oct 16:27 CDT 2021, Marijn Suijten wrote:
> 
> > On 2021-10-27 23:19:30, Marijn Suijten wrote:
> > > Hi Bjorn,
> > > 
> > > On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> > > > On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> > > > 
> > > > > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > > > > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > > > > with their output being routed to various other components, such as
> > > > > current sinks or GPIOs.
> > > > > 
> > > > > Each LPG instance can operate on fixed parameters or based on a shared
> > > > > lookup-table, altering the duty cycle over time. This provides the means
> > > > > for hardware assisted transitions of LED brightness.
> > > > > 
> > > > > A typical use case for the fixed parameter mode is to drive a PWM
> > > > > backlight control signal, the driver therefor allows each LPG instance
> > > > > to be exposed to the kernel either through the LED framework or the PWM
> > > > > framework.
> > > > > 
> > > > > A typical use case for the LED configuration is to drive RGB LEDs in
> > > > > smartphones etc, for which the driver support multiple channels to be
> > > > > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > > > > generators will be synchronized, to allow for multi-color patterns.
> > > > > 
> > > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > > ---
> > > > 
> > > > Any feedback on this?
> > > 
> > > I asked in #linux-msm whether anything is wrong with the patterns,
> > > since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
> > > pattern that's supposed to stay on for 1s and off for 1s:
> > > 
> > >     echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern
> > > 
> > > It however seems to be broken in the same way on an older version now
> > > (this might be v9 or v8) which I don't remember to be the case.  Can you
> > > double-check if this is all working fine on your side?  If so, I'll have
> > > to find some time to debug it on my end.
> > > 
> > > Thanks!
> > > - Marijn
> > 
> > Another thing I just ran into: on both patch revisions the colors are
> > flipped.  multi_index reports "red green glue", but the values written
> > to multi_intensity correspond to "blue green red" instead.  Is it the
> > same on your side?
> > 
> 
> I booted one of my 8974 devices with RGB LED and the colors matches my
> expectations. Can you confirm that your mapping in the DT node is
> correct?
> 
> E.g. with pm8941 the mapping should be "backwards":
> [snip]

Thanks, this was indeed a mistake on my side: downstream pm660l sets
blue to the first channel too, whereas I set it to red.  Let's blame it
on downstream mixing zero-based and one-based indices and my inability
to read that :)

- Marijn

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Marijn Suijten]

On 2022-01-28 18:50:42, Bjorn Andersson wrote:
> On Wed 27 Oct 16:19 CDT 2021, Marijn Suijten wrote:
> 
> > Hi Bjorn,
> > 
> > On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> > > On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> > > 
> > > > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > > > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > > > with their output being routed to various other components, such as
> > > > current sinks or GPIOs.
> > > > 
> > > > Each LPG instance can operate on fixed parameters or based on a shared
> > > > lookup-table, altering the duty cycle over time. This provides the means
> > > > for hardware assisted transitions of LED brightness.
> > > > 
> > > > A typical use case for the fixed parameter mode is to drive a PWM
> > > > backlight control signal, the driver therefor allows each LPG instance
> > > > to be exposed to the kernel either through the LED framework or the PWM
> > > > framework.
> > > > 
> > > > A typical use case for the LED configuration is to drive RGB LEDs in
> > > > smartphones etc, for which the driver support multiple channels to be
> > > > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > > > generators will be synchronized, to allow for multi-color patterns.
> > > > 
> > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > ---
> > > 
> > > Any feedback on this?
> > 
> > I asked in #linux-msm whether anything is wrong with the patterns,
> > since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
> > pattern that's supposed to stay on for 1s and off for 1s:
> > 
> >     echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern
> > 
> > It however seems to be broken in the same way on an older version now
> > (this might be v9 or v8) which I don't remember to be the case.  Can you
> > double-check if this is all working fine on your side?  If so, I'll have
> > to find some time to debug it on my end.
> > 
> 
> I had missed the fact that LPG_RAMP_DURATION_REG is two registers for
> msg and lsb, for a total of 9 bits of duration. So what you saw was
> probably ticking at 232ms.
> 
> Note though that the pattern uses the last time as "high pause", so I
> expect that you should have seen 232 ms of off, followed by 464ms of
> light.

Visual inspection seems to confirm those numbers indeed!

> I've fixed this for v11, both rejecting invalid input and writing out
> all 9 bits.

Doesn't that 512ms limit, together with using only the last value for
hi_pause (and not the first value for lo_pause) force users to write
patterns in a certain way which is not easily conveyed to the caller
except by reading the comment in the driver?  I'd guess lo_pause can be
used even if not in ping-pong mode, it should just hold at the first
value for the given duration?

(That said hw_pattern is anyway already riddled with device-specific
information, such as only having one `delta_t` which functions as the
step size for every entry, and with the change above would need to be
sourced from another step that's not the first.)

Bit of a stretch, but perhaps worth noting anyway: should this be
written in documentation somewhere, together with pattern examples and
their desired outcome to function as testcases too?

- Marijn

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Bjorn Andersson]

On Wed 02 Feb 03:03 PST 2022, Marijn Suijten wrote:

> On 2022-01-28 18:50:42, Bjorn Andersson wrote:
> > On Wed 27 Oct 16:19 CDT 2021, Marijn Suijten wrote:
> > 
> > > Hi Bjorn,
> > > 
> > > On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> > > > On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> > > > 
> > > > > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > > > > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > > > > with their output being routed to various other components, such as
> > > > > current sinks or GPIOs.
> > > > > 
> > > > > Each LPG instance can operate on fixed parameters or based on a shared
> > > > > lookup-table, altering the duty cycle over time. This provides the means
> > > > > for hardware assisted transitions of LED brightness.
> > > > > 
> > > > > A typical use case for the fixed parameter mode is to drive a PWM
> > > > > backlight control signal, the driver therefor allows each LPG instance
> > > > > to be exposed to the kernel either through the LED framework or the PWM
> > > > > framework.
> > > > > 
> > > > > A typical use case for the LED configuration is to drive RGB LEDs in
> > > > > smartphones etc, for which the driver support multiple channels to be
> > > > > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > > > > generators will be synchronized, to allow for multi-color patterns.
> > > > > 
> > > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > > ---
> > > > 
> > > > Any feedback on this?
> > > 
> > > I asked in #linux-msm whether anything is wrong with the patterns,
> > > since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
> > > pattern that's supposed to stay on for 1s and off for 1s:
> > > 
> > >     echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern
> > > 
> > > It however seems to be broken in the same way on an older version now
> > > (this might be v9 or v8) which I don't remember to be the case.  Can you
> > > double-check if this is all working fine on your side?  If so, I'll have
> > > to find some time to debug it on my end.
> > > 
> > 
> > I had missed the fact that LPG_RAMP_DURATION_REG is two registers for
> > msg and lsb, for a total of 9 bits of duration. So what you saw was
> > probably ticking at 232ms.
> > 
> > Note though that the pattern uses the last time as "high pause", so I
> > expect that you should have seen 232 ms of off, followed by 464ms of
> > light.
> 
> Visual inspection seems to confirm those numbers indeed!
> 
> > I've fixed this for v11, both rejecting invalid input and writing out
> > all 9 bits.
> 
> Doesn't that 512ms limit, together with using only the last value for
> hi_pause (and not the first value for lo_pause) force users to write
> patterns in a certain way which is not easily conveyed to the caller
> except by reading the comment in the driver?  I'd guess lo_pause can be
> used even if not in ping-pong mode, it should just hold at the first
> value for the given duration?
> 
> (That said hw_pattern is anyway already riddled with device-specific
> information, such as only having one `delta_t` which functions as the
> step size for every entry, and with the change above would need to be
> sourced from another step that's not the first.)
> 

Perhaps we should clarify the single delta_t by requiring all those
delta_t to be the same, rather than ignoring their value.

I.e. we make the ping-pong pattern:

<value> <lopause+t> ... <value[N/2-1]> <t> <value[N/2]> <hipause+t> <value[N/2-1]> <t> ... <value> <t>

And for non-ping-pong:

<value> <lopause+t> <value> <t> ... <value> <t> <value> <hipause + t>


What do you think?

> Bit of a stretch, but perhaps worth noting anyway: should this be
> written in documentation somewhere, together with pattern examples and
> their desired outcome to function as testcases too?
> 

There's a comment in lpg_pattern_set() where I tried to capture this.

I don't think it's worth documenting the behavior/structure away from
the driver. But let's make sure it's captured properly there.

Regards,
Bjorn

Re: [PATCH v10 2/2] leds: Add driver for Qualcomm LPG

[Marijn Suijten]

On 2022-02-02 13:56:10, Bjorn Andersson wrote:
> On Wed 02 Feb 03:03 PST 2022, Marijn Suijten wrote:
> 
> > On 2022-01-28 18:50:42, Bjorn Andersson wrote:
> > > On Wed 27 Oct 16:19 CDT 2021, Marijn Suijten wrote:
> > > 
> > > > Hi Bjorn,
> > > > 
> > > > On 2021-10-22 10:25:35, Bjorn Andersson wrote:
> > > > > On Sat 09 Oct 21:39 PDT 2021, Bjorn Andersson wrote:
> > > > > 
> > > > > > The Light Pulse Generator (LPG) is a PWM-block found in a wide range of
> > > > > > PMICs from Qualcomm. These PMICs typically comes with 1-8 LPG instances,
> > > > > > with their output being routed to various other components, such as
> > > > > > current sinks or GPIOs.
> > > > > > 
> > > > > > Each LPG instance can operate on fixed parameters or based on a shared
> > > > > > lookup-table, altering the duty cycle over time. This provides the means
> > > > > > for hardware assisted transitions of LED brightness.
> > > > > > 
> > > > > > A typical use case for the fixed parameter mode is to drive a PWM
> > > > > > backlight control signal, the driver therefor allows each LPG instance
> > > > > > to be exposed to the kernel either through the LED framework or the PWM
> > > > > > framework.
> > > > > > 
> > > > > > A typical use case for the LED configuration is to drive RGB LEDs in
> > > > > > smartphones etc, for which the driver support multiple channels to be
> > > > > > ganged up to a MULTICOLOR LED. In this configuration the pattern
> > > > > > generators will be synchronized, to allow for multi-color patterns.
> > > > > > 
> > > > > > Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
> > > > > > ---
> > > > > 
> > > > > Any feedback on this?
> > > > 
> > > > I asked in #linux-msm whether anything is wrong with the patterns,
> > > > since my Sony Discovery (sdm630 with a pm660l) blinks way quicker on a
> > > > pattern that's supposed to stay on for 1s and off for 1s:
> > > > 
> > > >     echo "0 1000 255 1000" > /sys/class/leds/rgb\:status/hw_pattern
> > > > 
> > > > It however seems to be broken in the same way on an older version now
> > > > (this might be v9 or v8) which I don't remember to be the case.  Can you
> > > > double-check if this is all working fine on your side?  If so, I'll have
> > > > to find some time to debug it on my end.
> > > > 
> > > 
> > > I had missed the fact that LPG_RAMP_DURATION_REG is two registers for
> > > msg and lsb, for a total of 9 bits of duration. So what you saw was
> > > probably ticking at 232ms.
> > > 
> > > Note though that the pattern uses the last time as "high pause", so I
> > > expect that you should have seen 232 ms of off, followed by 464ms of
> > > light.
> > 
> > Visual inspection seems to confirm those numbers indeed!
> > 
> > > I've fixed this for v11, both rejecting invalid input and writing out
> > > all 9 bits.
> > 
> > Doesn't that 512ms limit, together with using only the last value for
> > hi_pause (and not the first value for lo_pause) force users to write
> > patterns in a certain way which is not easily conveyed to the caller
> > except by reading the comment in the driver?  I'd guess lo_pause can be
> > used even if not in ping-pong mode, it should just hold at the first
> > value for the given duration?
> > 
> > (That said hw_pattern is anyway already riddled with device-specific
> > information, such as only having one `delta_t` which functions as the
> > step size for every entry, and with the change above would need to be
> > sourced from another step that's not the first.)
> > 
> 
> Perhaps we should clarify the single delta_t by requiring all those
> delta_t to be the same, rather than ignoring their value.
> 
> I.e. we make the ping-pong pattern:
> 
> <value> <lopause+t> ... <value[N/2-1]> <t> <value[N/2]> <hipause+t> <value[N/2-1]> <t> ... <value> <t>
> 
> And for non-ping-pong:
> 
> <value> <lopause+t> <value> <t> ... <value> <t> <value> <hipause + t>
> 
> 
> What do you think?

Seems like a good idea, though we'll have to be careful to communicate
this lopause+t value for the first entry and hipause+t for the
middle/last (through a dev_err I suppose) in case we reject values that
don't strictly adhere to this math.

> > Bit of a stretch, but perhaps worth noting anyway: should this be
> > written in documentation somewhere, together with pattern examples and
> > their desired outcome to function as testcases too?
> > 
> 
> There's a comment in lpg_pattern_set() where I tried to capture this.
> 
> I don't think it's worth documenting the behavior/structure away from
> the driver. But let's make sure it's captured properly there.

I've seen two other dirvers document the hw_pattern sysfs property under
Documentation/leds/.  Should be easier to find than a comment inside the
respective function deep in the kernel source tree I presume?

Quoting Documentation/ABI/testing/sysfs-class-led-trigger-pattern for
this sysfs property:

    Since different LED hardware can have different semantics of
    hardware patterns, each driver is expected to provide its own
    description for the hardware patterns in their documentation
    file at Documentation/leds/.

Doesn't need to be anything long, copying your inline comment would be a
great start.  Thanks!

- Marijn