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kernel: add upstream patches for pca955x led driver
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These patches are to support the pca955x led with OpenWRT correctly via
device tree on linux 5.10. Without these, the new LED function/color/reg
features can not be used.

Signed-off-by: Chris Blake <chrisrblake93@gmail.com>
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@riptidewave93 @chunkeey
riptidewave93 authored and chunkeey committed Jun 19, 2022
1 parent 2e0afef commit 78ecaeb
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178 changes: 178 additions & 0 deletions target/linux/generic/backport-5.10/840-v5.15-leds-pca955x-clean-up-code-formatting.patch
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@@ -0,0 +1,178 @@
From 2420ae02ce0a926819ebe18f809a57bff3edeac2 Mon Sep 17 00:00:00 2001
From: Eddie James <eajames@linux.ibm.com>
Date: Fri, 16 Jul 2021 17:03:27 -0500
Subject: [PATCH] leds: pca955x: Clean up code formatting

Format the code. Add some variables to help shorten lines.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
---
drivers/leds/leds-pca955x.c | 63 ++++++++++++++++++-------------------
1 file changed, 30 insertions(+), 33 deletions(-)

diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index 7087ca4592fc96..f0d841cb59fcc8 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -166,11 +166,10 @@ static inline u8 pca955x_ledsel(u8 oldval, int led_num, int state)
static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
+ u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + (2 * n);
int ret;

- ret = i2c_smbus_write_byte_data(client,
- pca95xx_num_input_regs(pca955x->chipdef->bits) + 2*n,
- val);
+ ret = i2c_smbus_write_byte_data(client, cmd, val);
if (ret < 0)
dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
__func__, n, val, ret);
@@ -187,11 +186,10 @@ static int pca955x_write_psc(struct i2c_client *client, int n, u8 val)
static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
+ u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
int ret;

- ret = i2c_smbus_write_byte_data(client,
- pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + 2*n,
- val);
+ ret = i2c_smbus_write_byte_data(client, cmd, val);
if (ret < 0)
dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
__func__, n, val, ret);
@@ -205,11 +203,10 @@ static int pca955x_write_pwm(struct i2c_client *client, int n, u8 val)
static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
+ u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
int ret;

- ret = i2c_smbus_write_byte_data(client,
- pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n,
- val);
+ ret = i2c_smbus_write_byte_data(client, cmd, val);
if (ret < 0)
dev_err(&client->dev, "%s: reg 0x%x, val 0x%x, err %d\n",
__func__, n, val, ret);
@@ -223,10 +220,10 @@ static int pca955x_write_ls(struct i2c_client *client, int n, u8 val)
static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
{
struct pca955x *pca955x = i2c_get_clientdata(client);
+ u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n;
int ret;

- ret = i2c_smbus_read_byte_data(client,
- pca95xx_num_input_regs(pca955x->chipdef->bits) + 4 + n);
+ ret = i2c_smbus_read_byte_data(client, cmd);
if (ret < 0) {
dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
__func__, n, ret);
@@ -371,6 +368,7 @@ static struct pca955x_platform_data *
pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
{
struct pca955x_platform_data *pdata;
+ struct pca955x_led *led;
struct fwnode_handle *child;
int count;

@@ -401,13 +399,13 @@ pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
if ((res != 0) && is_of_node(child))
name = to_of_node(child)->name;

- snprintf(pdata->leds[reg].name, sizeof(pdata->leds[reg].name),
- "%s", name);
+ led = &pdata->leds[reg];
+ snprintf(led->name, sizeof(led->name), "%s", name);

- pdata->leds[reg].type = PCA955X_TYPE_LED;
- fwnode_property_read_u32(child, "type", &pdata->leds[reg].type);
+ led->type = PCA955X_TYPE_LED;
+ fwnode_property_read_u32(child, "type", &led->type);
fwnode_property_read_string(child, "linux,default-trigger",
- &pdata->leds[reg].default_trigger);
+ &led->default_trigger);
}

pdata->num_leds = chip->bits;
@@ -426,11 +424,12 @@ static const struct of_device_id of_pca955x_match[] = {
MODULE_DEVICE_TABLE(of, of_pca955x_match);

static int pca955x_probe(struct i2c_client *client,
- const struct i2c_device_id *id)
+ const struct i2c_device_id *id)
{
struct pca955x *pca955x;
struct pca955x_led *pca955x_led;
struct pca955x_chipdef *chip;
+ struct led_classdev *led;
struct i2c_adapter *adapter;
int i, err;
struct pca955x_platform_data *pdata;
@@ -449,13 +448,13 @@ static int pca955x_probe(struct i2c_client *client,
if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
chip->slv_addr) {
dev_err(&client->dev, "invalid slave address %02x\n",
- client->addr);
+ client->addr);
return -ENODEV;
}

dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
- "slave address 0x%02x\n",
- client->name, chip->bits, client->addr);
+ "slave address 0x%02x\n", client->name, chip->bits,
+ client->addr);

if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -EIO;
@@ -471,8 +470,8 @@ static int pca955x_probe(struct i2c_client *client,
if (!pca955x)
return -ENOMEM;

- pca955x->leds = devm_kcalloc(&client->dev,
- chip->bits, sizeof(*pca955x_led), GFP_KERNEL);
+ pca955x->leds = devm_kcalloc(&client->dev, chip->bits,
+ sizeof(*pca955x_led), GFP_KERNEL);
if (!pca955x->leds)
return -ENOMEM;

@@ -501,27 +500,25 @@ static int pca955x_probe(struct i2c_client *client,
*/
if (pdata->leds[i].name[0] == '\0')
snprintf(pdata->leds[i].name,
- sizeof(pdata->leds[i].name), "%d", i);
+ sizeof(pdata->leds[i].name), "%d", i);

- snprintf(pca955x_led->name,
- sizeof(pca955x_led->name), "pca955x:%s",
- pdata->leds[i].name);
+ snprintf(pca955x_led->name, sizeof(pca955x_led->name),
+ "pca955x:%s", pdata->leds[i].name);

+ led = &pca955x_led->led_cdev;
if (pdata->leds[i].default_trigger)
- pca955x_led->led_cdev.default_trigger =
+ led->default_trigger =
pdata->leds[i].default_trigger;

- pca955x_led->led_cdev.name = pca955x_led->name;
- pca955x_led->led_cdev.brightness_set_blocking =
- pca955x_led_set;
+ led->name = pca955x_led->name;
+ led->brightness_set_blocking = pca955x_led_set;

- err = devm_led_classdev_register(&client->dev,
- &pca955x_led->led_cdev);
+ err = devm_led_classdev_register(&client->dev, led);
if (err)
return err;

/* Turn off LED */
- err = pca955x_led_set(&pca955x_led->led_cdev, LED_OFF);
+ err = pca955x_led_set(led, LED_OFF);
if (err)
return err;
}
83 changes: 83 additions & 0 deletions target/linux/generic/backport-5.10/841-v5.15-leds-pca955x-add-brightness-get-function.patch
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@@ -0,0 +1,83 @@
From 7086625fde6538b2c0623eb767ad23c7ac3d7f3a Mon Sep 17 00:00:00 2001
From: Eddie James <eajames@linux.ibm.com>
Date: Fri, 16 Jul 2021 17:03:28 -0500
Subject: [PATCH] leds: pca955x: Add brightness_get function

Add a function to fetch the state of the hardware LED.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
---
drivers/leds/leds-pca955x.c | 52 +++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)

diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index f0d841cb59fcc8..e47ba7c3b7c7d8 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -233,6 +233,57 @@ static int pca955x_read_ls(struct i2c_client *client, int n, u8 *val)
return 0;
}

+static int pca955x_read_pwm(struct i2c_client *client, int n, u8 *val)
+{
+ struct pca955x *pca955x = i2c_get_clientdata(client);
+ u8 cmd = pca95xx_num_input_regs(pca955x->chipdef->bits) + 1 + (2 * n);
+ int ret;
+
+ ret = i2c_smbus_read_byte_data(client, cmd);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s: reg 0x%x, err %d\n",
+ __func__, n, ret);
+ return ret;
+ }
+ *val = (u8)ret;
+ return 0;
+}
+
+static enum led_brightness pca955x_led_get(struct led_classdev *led_cdev)
+{
+ struct pca955x_led *pca955x_led = container_of(led_cdev,
+ struct pca955x_led,
+ led_cdev);
+ struct pca955x *pca955x = pca955x_led->pca955x;
+ u8 ls, pwm;
+ int ret;
+
+ ret = pca955x_read_ls(pca955x->client, pca955x_led->led_num / 4, &ls);
+ if (ret)
+ return ret;
+
+ ls = (ls >> ((pca955x_led->led_num % 4) << 1)) & 0x3;
+ switch (ls) {
+ case PCA955X_LS_LED_ON:
+ ret = LED_FULL;
+ break;
+ case PCA955X_LS_LED_OFF:
+ ret = LED_OFF;
+ break;
+ case PCA955X_LS_BLINK0:
+ ret = LED_HALF;
+ break;
+ case PCA955X_LS_BLINK1:
+ ret = pca955x_read_pwm(pca955x->client, 1, &pwm);
+ if (ret)
+ return ret;
+ ret = 255 - pwm;
+ break;
+ }
+
+ return ret;
+}
+
static int pca955x_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
@@ -512,6 +563,7 @@ static int pca955x_probe(struct i2c_client *client,

led->name = pca955x_led->name;
led->brightness_set_blocking = pca955x_led_set;
+ led->brightness_get = pca955x_led_get;

err = devm_led_classdev_register(&client->dev, led);
if (err)
119 changes: 119 additions & 0 deletions ...x/generic/backport-5.10/842-v5.15-leds-pca955x-implement-the-default-state-property.patch
View file
@@ -0,0 +1,119 @@
From e46cb6d0c760a5b15e38138845fad99628fafcb8 Mon Sep 17 00:00:00 2001
From: Eddie James <eajames@linux.ibm.com>
Date: Fri, 16 Jul 2021 17:03:29 -0500
Subject: [PATCH] leds: pca955x: Implement the default-state property

In order to retain the LED state after a system reboot, check the
documented default-state device tree property during initialization.
Modify the behavior of the probe according to the property.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
---
drivers/leds/leds-pca955x.c | 54 +++++++++++++++++++++++++++++++------
1 file changed, 46 insertions(+), 8 deletions(-)

diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c
index e47ba7c3b7c7d8..fa1d77d86ef67b 100644
--- a/drivers/leds/leds-pca955x.c
+++ b/drivers/leds/leds-pca955x.c
@@ -129,6 +129,7 @@ struct pca955x_led {
int led_num; /* 0 .. 15 potentially */
char name[32];
u32 type;
+ int default_state;
const char *default_trigger;
};

@@ -439,6 +440,7 @@ pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)

device_for_each_child_node(&client->dev, child) {
const char *name;
+ const char *state;
u32 reg;
int res;

@@ -457,6 +459,18 @@ pca955x_get_pdata(struct i2c_client *client, struct pca955x_chipdef *chip)
fwnode_property_read_u32(child, "type", &led->type);
fwnode_property_read_string(child, "linux,default-trigger",
&led->default_trigger);
+
+ if (!fwnode_property_read_string(child, "default-state",
+ &state)) {
+ if (!strcmp(state, "keep"))
+ led->default_state = LEDS_GPIO_DEFSTATE_KEEP;
+ else if (!strcmp(state, "on"))
+ led->default_state = LEDS_GPIO_DEFSTATE_ON;
+ else
+ led->default_state = LEDS_GPIO_DEFSTATE_OFF;
+ } else {
+ led->default_state = LEDS_GPIO_DEFSTATE_OFF;
+ }
}

pdata->num_leds = chip->bits;
@@ -485,6 +499,7 @@ static int pca955x_probe(struct i2c_client *client,
int i, err;
struct pca955x_platform_data *pdata;
int ngpios = 0;
+ bool keep_pwm = false;

chip = &pca955x_chipdefs[id->driver_data];
adapter = client->adapter;
@@ -565,14 +580,35 @@ static int pca955x_probe(struct i2c_client *client,
led->brightness_set_blocking = pca955x_led_set;
led->brightness_get = pca955x_led_get;

+ if (pdata->leds[i].default_state ==
+ LEDS_GPIO_DEFSTATE_OFF) {
+ err = pca955x_led_set(led, LED_OFF);
+ if (err)
+ return err;
+ } else if (pdata->leds[i].default_state ==
+ LEDS_GPIO_DEFSTATE_ON) {
+ err = pca955x_led_set(led, LED_FULL);
+ if (err)
+ return err;
+ }
+
err = devm_led_classdev_register(&client->dev, led);
if (err)
return err;

- /* Turn off LED */
- err = pca955x_led_set(led, LED_OFF);
- if (err)
- return err;
+ /*
+ * For default-state == "keep", let the core update the
+ * brightness from the hardware, then check the
+ * brightness to see if it's using PWM1. If so, PWM1
+ * should not be written below.
+ */
+ if (pdata->leds[i].default_state ==
+ LEDS_GPIO_DEFSTATE_KEEP) {
+ if (led->brightness != LED_FULL &&
+ led->brightness != LED_OFF &&
+ led->brightness != LED_HALF)
+ keep_pwm = true;
+ }
}
}

@@ -581,10 +617,12 @@ static int pca955x_probe(struct i2c_client *client,
if (err)
return err;

- /* PWM1 is used for variable brightness, default to OFF */
- err = pca955x_write_pwm(client, 1, 0);
- if (err)
- return err;
+ if (!keep_pwm) {
+ /* PWM1 is used for variable brightness, default to OFF */
+ err = pca955x_write_pwm(client, 1, 0);
+ if (err)
+ return err;
+ }

/* Set to fast frequency so we do not see flashing */
err = pca955x_write_psc(client, 0, 0);

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