On Fri, Feb 11, 2022 at 10:19:24AM +0100, Javier Martinez Canillas wrote:
> This adds a DRM driver for SSD1305, SSD1306, SSD1307 and SSD1309 Solomon
> OLED display controllers.
>
> It's only the core part of the driver and a bus specific driver is needed
> for each transport interface supported by the display controllers.
...
> +#include <linux/backlight.h>
> +#include <linux/bitfield.h>
bits.h
(FYI, specifically sent a patch few days ago to add explicitly the inclusions
that needed for bitfield operations in the example inside bitfield.h).
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/property.h>
> +#include <linux/pwm.h>
> +#include <linux/regulator/consumer.h>
...
> +#define SSD130X_SET_ADDRESS_MODE_HORIZONTAL (0x00)
> +#define SSD130X_SET_ADDRESS_MODE_VERTICAL (0x01)
> +#define SSD130X_SET_ADDRESS_MODE_PAGE (0x02)
> +
> +#define SSD130X_SET_AREA_COLOR_MODE_ENABLE (0x1e)
> +#define SSD130X_SET_AREA_COLOR_MODE_LOW_POWER (0x05)
Do the parentheses add anything here?
...
> +/*
> + * Helper to write command (SSD130X_COMMAND). The fist variadic argument
> + * is the command to write and the following are the command options.
This is not correct explanation. Please, rephrase to show that _each_ of the
options is sent with a preceding command.
> + */
> +static int ssd130x_write_cmd(struct ssd130x_device *ssd130x, int count,
> + /* u8 cmd, u8 option, ... */...)
> +{
> + va_list ap;
> + u8 value;
> + int ret;
> +
> + va_start(ap, count);
> +
> + do {
> + value = va_arg(ap, int);
> + ret = regmap_write(ssd130x->regmap, SSD130X_COMMAND, (u8)value);
> + if (ret)
> + goto out_end;
> + } while (--count);
> +
> +out_end:
> + va_end(ap);
> +
> + return ret;
> +}
...
> + if (ssd130x->device_info->need_pwm) {
Yeah, unfortunately we still don't have pwm_get_optional()...
> + ret = ssd130x_pwm_enable(ssd130x);
> + if (ret) {
> + dev_err(dev, "Failed to enable PWM: %d\n", ret);
> + regulator_disable(ssd130x->vcc_reg);
> + return ret;
> + }
> + }
...
> +static void ssd130x_power_off(struct ssd130x_device *ssd130x)
> +{
> + if (ssd130x->device_info->need_pwm) {
Redundant check. The two below are NULL-aware.
> + pwm_disable(ssd130x->pwm);
> + pwm_put(ssd130x->pwm);
> + }
> +
> + regulator_disable(ssd130x->vcc_reg);
> +}
...
> + ret = ssd130x_write_cmd(ssd130x, 2, SSD130X_SET_COM_PINS_CONFIG, compins);
> + if (ret < 0)
> + return ret;
> +
> +
One blank line is enough.
...
> + for (i = y / 8; i < y / 8 + pages; i++) {
> + int m = 8;
> +
> + /* Last page may be partial */
> + if (8 * (i + 1) > ssd130x->height)
> + m = ssd130x->height % 8;
Perhaps it can be moved out of the loop with refactored piece below.
> + for (j = x; j < x + width; j++) {
> + u8 data = 0;
> +
> + for (k = 0; k < m; k++) {
> + u8 byte = buf[(8 * i + k) * line_length + j / 8];
> + u8 bit = (byte >> (j % 8)) & 1;
> +
> + data |= bit << k;
> + }
> + data_array[array_idx++] = data;
> + }
> + }
...
> + bl = devm_backlight_device_register(dev, dev_name(dev), dev, ssd130x,
> + &ssd130xfb_bl_ops, NULL);
> + if (IS_ERR(bl)) {
> + ret = PTR_ERR(bl);
> + dev_err_probe(dev, ret, "Unable to register backlight device\n");
> + return ERR_PTR(ret);
dev_err_probe(dev, PTR_ERR(bl), "Unable to register backlight device\n");
return bl;
?
> + }
--
With Best Regards,
Andy Shevchenko
