diff options
| author | Eddie James <eajames@linux.ibm.com> | 2025-02-12 17:30:37 +0300 |
|---|---|---|
| committer | Lee Jones <lee@kernel.org> | 2025-02-20 17:29:13 +0300 |
| commit | 14ef0738a31dcecfbba38626884b7d9a60b75cd0 (patch) | |
| tree | 9412f2a26b3ebc5bd5125976415ff43989a1c927 | |
| parent | 1ddab1e2de10a37b66b235cff30e5b0a0beb8809 (diff) | |
| download | linux-14ef0738a31dcecfbba38626884b7d9a60b75cd0.tar.xz | |
leds: pca955x: Optimize probe LED selection
Previously, the probe function might do up to 32 reads and writes
to the same 4 registers to program the LED selection. Reduce this to
a maximum of 5 operations by accumulating the changes to the LED
selection and comparing with the previous value to write the
selection if different.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20250212143038.1416501-4-eajames@linux.ibm.com
Signed-off-by: Lee Jones <lee@kernel.org>
| -rw-r--r-- | drivers/leds/leds-pca955x.c | 38 |
1 files changed, 28 insertions, 10 deletions
diff --git a/drivers/leds/leds-pca955x.c b/drivers/leds/leds-pca955x.c index 4990f8aff6d1..eb268e6ee2a8 100644 --- a/drivers/leds/leds-pca955x.c +++ b/drivers/leds/leds-pca955x.c @@ -446,7 +446,9 @@ static int pca955x_probe(struct i2c_client *client) struct led_classdev *led; struct led_init_data init_data; struct i2c_adapter *adapter; - int i, err; + int i, bit, err, nls, reg; + u8 ls1[4]; + u8 ls2[4]; struct pca955x_platform_data *pdata; bool set_default_label = false; bool keep_pwm = false; @@ -504,6 +506,17 @@ static int pca955x_probe(struct i2c_client *client) init_data.devname_mandatory = false; init_data.devicename = "pca955x"; + nls = pca955x_num_led_regs(chip->bits); + /* Use auto-increment feature to read all the LED selectors at once. */ + err = i2c_smbus_read_i2c_block_data(client, + 0x10 | (pca955x_num_input_regs(chip->bits) + 4), nls, + ls1); + if (err < 0) + return err; + + for (i = 0; i < nls; i++) + ls2[i] = ls1[i]; + for (i = 0; i < chip->bits; i++) { pca955x_led = &pca955x->leds[i]; pca955x_led->led_num = i; @@ -515,19 +528,16 @@ static int pca955x_probe(struct i2c_client *client) case PCA955X_TYPE_GPIO: break; case PCA955X_TYPE_LED: + bit = i % 4; + reg = i / 4; led = &pca955x_led->led_cdev; led->brightness_set_blocking = pca955x_led_set; led->brightness_get = pca955x_led_get; - if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF) { - err = pca955x_led_set(led, LED_OFF); - if (err) - return err; - } else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON) { - err = pca955x_led_set(led, LED_FULL); - if (err) - return err; - } + if (pdata->leds[i].default_state == LEDS_DEFSTATE_OFF) + ls2[reg] = pca955x_ledsel(ls2[reg], bit, PCA955X_LS_LED_OFF); + else if (pdata->leds[i].default_state == LEDS_DEFSTATE_ON) + ls2[reg] = pca955x_ledsel(ls2[reg], bit, PCA955X_LS_LED_ON); init_data.fwnode = pdata->leds[i].fwnode; @@ -571,6 +581,14 @@ static int pca955x_probe(struct i2c_client *client) } } + for (i = 0; i < nls; i++) { + if (ls1[i] != ls2[i]) { + err = pca955x_write_ls(pca955x, i, ls2[i]); + if (err) + return err; + } + } + /* PWM0 is used for half brightness or 50% duty cycle */ err = pca955x_write_pwm(pca955x, 0, 255 - LED_HALF); if (err) |