[PATCH v3 6/7] leds: rgb: leds-qcom-lpg: Support two-nvmem PPG Scheme

From: Anjelique Melendez
Date: Mon Aug 14 2023 - 20:02:25 EST


On PMICs such as PM8350C, the lookup table containing the pattern data
is stored in a separate nvmem device from the one where the per-channel
data is stored.

Add support for two separate nvmems to handle this case while maintaining
backward compatibility for those targets that use only a single nvmem
device.

Signed-off-by: Guru Das Srinagesh <quic_gurus@xxxxxxxxxxx>
Signed-off-by: Anjelique Melendez <quic_amelende@xxxxxxxxxxx>
---
drivers/leds/rgb/leds-qcom-lpg.c | 112 ++++++++++++++++++++++++-------
1 file changed, 89 insertions(+), 23 deletions(-)

diff --git a/drivers/leds/rgb/leds-qcom-lpg.c b/drivers/leds/rgb/leds-qcom-lpg.c
index 822c7bff00df..f3f83925ab41 100644
--- a/drivers/leds/rgb/leds-qcom-lpg.c
+++ b/drivers/leds/rgb/leds-qcom-lpg.c
@@ -60,6 +60,7 @@
#define RAMP_STEP_DURATION(x) (((x) * 1000 / DEFAULT_TICK_DURATION_US) & 0xff)

/* LPG common config settings for PPG */
+#define SDAM_START_BASE 0x40
#define SDAM_REG_RAMP_STEP_DURATION 0x47
#define SDAM_LUT_COUNT_MAX 64

@@ -69,6 +70,8 @@
#define SDAM_END_INDEX_OFFSET 0x3
#define SDAM_START_INDEX_OFFSET 0x4
#define SDAM_PBS_SCRATCH_LUT_COUNTER_OFFSET 0x6
+#define SDAM_PAUSE_HI_MULTIPLIER_OFFSET 0x8
+#define SDAM_PAUSE_LO_MULTIPLIER_OFFSET 0x9

struct lpg_channel;
struct lpg_data;
@@ -85,7 +88,9 @@ struct lpg_data;
* @lut_bitmap: allocation bitmap for LUT entries
* @pbs_dev: PBS device
* @lpg_chan_nvmem: LPG nvmem peripheral device
+ * @lut_nvmem: LUT nvmem peripheral device
* @pbs_en_bitmap: bitmap for tracking PBS triggers
+ * @nvmem_count: number of nvmems used for LUT and PPG config
* @lut_sdam_base: offset where LUT pattern begins in nvmem
* @ppg_en: Flag indicating whether PPG is enabled/used
* @triled_base: base address of the TRILED block (optional)
@@ -111,7 +116,9 @@ struct lpg {

struct pbs_dev *pbs_dev;
struct nvmem_device *lpg_chan_nvmem;
+ struct nvmem_device *lut_nvmem;
unsigned long pbs_en_bitmap;
+ unsigned int nvmem_count;
u32 lut_sdam_base;
bool ppg_en;

@@ -261,6 +268,8 @@ static int lpg_sdam_write(struct lpg *lpg, u16 addr, u8 val)
}

#define SDAM_REG_PBS_SEQ_EN 0x42
+#define SDAM_PBS_TRIG_SET 0xe5
+#define SDAM_PBS_TRIG_CLR 0xe6
#define PBS_SW_TRIG_BIT BIT(0)

static int lpg_clear_pbs_trigger(struct lpg_channel *chan)
@@ -272,6 +281,12 @@ static int lpg_clear_pbs_trigger(struct lpg_channel *chan)
rc = lpg_sdam_write(chan->lpg, SDAM_REG_PBS_SEQ_EN, 0);
if (rc < 0)
return rc;
+
+ if (chan->lpg->nvmem_count == 2) {
+ rc = lpg_sdam_write(chan->lpg, SDAM_PBS_TRIG_CLR, PBS_SW_TRIG_BIT);
+ if (rc < 0)
+ return rc;
+ }
}

return 0;
@@ -286,9 +301,15 @@ static int lpg_set_pbs_trigger(struct lpg_channel *chan)
if (rc < 0)
return rc;

- rc = qcom_pbs_trigger_event(chan->lpg->pbs_dev, PBS_SW_TRIG_BIT);
- if (rc < 0)
- return rc;
+ if (chan->lpg->nvmem_count == 1) {
+ rc = qcom_pbs_trigger_event(chan->lpg->pbs_dev, PBS_SW_TRIG_BIT);
+ if (rc < 0)
+ return rc;
+ } else {
+ rc = lpg_sdam_write(chan->lpg, SDAM_PBS_TRIG_SET, PBS_SW_TRIG_BIT);
+ if (rc < 0)
+ return rc;
+ }
}
set_bit(chan->lpg_idx, &chan->lpg->pbs_en_bitmap);

@@ -342,7 +363,12 @@ static int lpg_lut_store_sdam(struct lpg *lpg, struct led_pattern *pattern,
for (i = 0; i < len; i++) {
brightness = pattern[i].brightness;
addr = lpg->lut_sdam_base + i + idx;
- rc = lpg_sdam_write(lpg, addr, brightness);
+
+ if (lpg->nvmem_count == 1)
+ rc = lpg_sdam_write(lpg, addr, brightness);
+ else
+ rc = nvmem_device_write(lpg->lut_nvmem, addr, 1, &brightness);
+
if (rc < 0)
return rc;
}
@@ -601,24 +627,48 @@ static void lpg_apply_pwm_value(struct lpg_channel *chan)
#define LPG_PATTERN_CONFIG_PAUSE_HI BIT(1)
#define LPG_PATTERN_CONFIG_PAUSE_LO BIT(0)

+static u8 lpg_get_sdam_lut_idx(struct lpg_channel *chan, u8 idx)
+{
+ if (chan->lpg->nvmem_count == 2)
+ return chan->lpg->lut_sdam_base - SDAM_START_BASE + idx;
+ return idx;
+}
+
static void lpg_sdam_apply_lut_control(struct lpg_channel *chan)
{
u8 val, conf = 0;
+ unsigned int hi_pause, lo_pause;
struct lpg *lpg = chan->lpg;

+ hi_pause = DIV_ROUND_UP(chan->ramp_hi_pause_ms, chan->ramp_tick_ms);
+ lo_pause = DIV_ROUND_UP(chan->ramp_lo_pause_ms, chan->ramp_tick_ms);
+
if (!chan->ramp_oneshot)
conf |= LPG_PATTERN_CONFIG_REPEAT;
+ if (chan->ramp_hi_pause_ms && lpg->nvmem_count != 1)
+ conf |= LPG_PATTERN_CONFIG_PAUSE_HI;
+ if (chan->ramp_lo_pause_ms && lpg->nvmem_count != 1)
+ conf |= LPG_PATTERN_CONFIG_PAUSE_LO;

lpg_sdam_write(lpg, SDAM_PBS_SCRATCH_LUT_COUNTER_OFFSET + chan->sdam_offset, 0);
lpg_sdam_write(lpg, SDAM_PATTERN_CONFIG_OFFSET + chan->sdam_offset, conf);

- lpg_sdam_write(lpg, SDAM_END_INDEX_OFFSET + chan->sdam_offset, chan->pattern_hi_idx);
- lpg_sdam_write(lpg, SDAM_START_INDEX_OFFSET + chan->sdam_offset, chan->pattern_lo_idx);
+ val = lpg_get_sdam_lut_idx(chan, chan->pattern_hi_idx);
+ lpg_sdam_write(lpg, SDAM_END_INDEX_OFFSET + chan->sdam_offset, val);
+
+ val = lpg_get_sdam_lut_idx(chan, chan->pattern_lo_idx);
+ lpg_sdam_write(lpg, SDAM_START_INDEX_OFFSET + chan->sdam_offset, val);

val = RAMP_STEP_DURATION(chan->ramp_tick_ms);
if (val > 0)
val--;
lpg_sdam_write(lpg, SDAM_REG_RAMP_STEP_DURATION, val);
+
+ if (lpg->nvmem_count != 1) {
+ lpg_sdam_write(lpg, SDAM_PAUSE_HI_MULTIPLIER_OFFSET + chan->sdam_offset, hi_pause);
+ lpg_sdam_write(lpg, SDAM_PAUSE_LO_MULTIPLIER_OFFSET + chan->sdam_offset, lo_pause);
+ }
+
}

static void lpg_apply_lut_control(struct lpg_channel *chan)
@@ -1000,8 +1050,8 @@ static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *led_pattern,
* enabled. In this scenario the delta_t of the middle entry (i.e. the
* last in the programmed pattern) determines the "high pause".
*
- * NVMEM devices supporting LUT do not support "low pause", "high pause"
- * or "ping pong"
+ * All NVMEM devices supporting LUT do not support "ping pong"
+ * Single NVMEM devices supporting LUT do not support "low pause" and "high pause"
*/

/* Detect palindromes and use "ping pong" to reduce LUT usage */
@@ -1028,7 +1078,7 @@ static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *led_pattern,
* Validate that all delta_t in the pattern are the same, with the
* exception of the middle element in case of ping_pong.
*/
- if (lpg->ppg_en) {
+ if (lpg->nvmem_count == 1) {
i = 1;
delta_t = pattern[0].delta_t;
} else {
@@ -1042,7 +1092,7 @@ static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *led_pattern,
* Allow last entry in the full or shortened pattern to
* specify hi pause. Reject other variations.
*/
- if (i != actual_len - 1 || lpg->ppg_en)
+ if (i != actual_len - 1 || lpg->nvmem_count == 1)
goto out_free_pattern;
}
}
@@ -1051,8 +1101,8 @@ static int lpg_pattern_set(struct lpg_led *led, struct led_pattern *led_pattern,
if (delta_t >= BIT(9))
goto out_free_pattern;

- /* Find "low pause" and "high pause" in the pattern if not an NVMEM device*/
- if (!lpg->ppg_en) {
+ /* Find "low pause" and "high pause" in the pattern if not a single NVMEM device*/
+ if (lpg->nvmem_count != 1) {
lo_pause = pattern[0].delta_t;
hi_pause = pattern[actual_len - 1].delta_t;
}
@@ -1509,29 +1559,45 @@ static int lpg_parse_sdam(struct lpg *lpg)
{
int rc = 0;

- if (lpg->data->nvmem_count == 0)
+ lpg->nvmem_count = lpg->data->nvmem_count;
+ if (lpg->nvmem_count == 0)
return 0;

- /* get the nvmem device for LPG/LUT config */
+ if (lpg->nvmem_count > 2)
+ return -EINVAL;
+
+ /* get the 1st nvmem device for LPG/LUT config */
lpg->lpg_chan_nvmem = devm_nvmem_device_get(lpg->dev, "lpg_chan_sdam");
if (IS_ERR(lpg->lpg_chan_nvmem)) {
rc = PTR_ERR(lpg->lpg_chan_nvmem);
- if (rc != -EPROBE_DEFER)
- dev_err(lpg->dev, "Failed to get nvmem device, rc=%d\n", rc);
- return rc;
+ goto err;
}

- lpg->pbs_dev = get_pbs_client_device(lpg->dev);
- if (IS_ERR(lpg->pbs_dev)) {
- rc = PTR_ERR(lpg->pbs_dev);
- if (rc != -EPROBE_DEFER)
- dev_err(lpg->dev, "Failed to get PBS client device, rc=%d\n", rc);
- return rc;
+ if (lpg->nvmem_count == 1) {
+ /* get PBS device node if single NVMEM device */
+ lpg->pbs_dev = get_pbs_client_device(lpg->dev);
+ if (IS_ERR(lpg->pbs_dev)) {
+ rc = PTR_ERR(lpg->pbs_dev);
+ if (rc != -EPROBE_DEFER)
+ dev_err(lpg->dev, "Failed to get PBS client device, rc=%d\n", rc);
+ return rc;
+ }
+ } else if (lpg->nvmem_count == 2) {
+ /* get the 2nd nvmem device for LUT pattern */
+ lpg->lut_nvmem = devm_nvmem_device_get(lpg->dev, "lut_sdam");
+ if (IS_ERR(lpg->lut_nvmem)) {
+ rc = PTR_ERR(lpg->lut_nvmem);
+ goto err;
+ }
}

lpg->ppg_en = true;

return rc;
+err:
+ if (rc != -EPROBE_DEFER)
+ dev_err(lpg->dev, "Failed to get nvmem device, rc=%d\n", rc);
+ return rc;
}

static int lpg_init_sdam(struct lpg *lpg)
--
2.41.0