[PATCH v6 10/14] drm/panel: add S6E3FA0 driver
YoungJun Cho
yj44.cho at samsung.com
Thu Jul 17 18:49:35 PDT 2014
Hi Thierry,
Thank you a lot for kind comments.
On 07/17/2014 07:36 PM, Thierry Reding wrote:
> On Thu, Jul 17, 2014 at 06:01:25PM +0900, YoungJun Cho wrote:
> [...]
>> diff --git a/drivers/gpu/drm/panel/panel-s6e3fa0.c b/drivers/gpu/drm/panel/panel-s6e3fa0.c
> [...]
>> +/* Manufacturer Command Set */
>> +#define MCS_GLOBAL_PARAMETER 0xb0
>> +#define MCS_AID 0xb2
>> +#define MCS_ELVSSOPT 0xb6
>> +#define MCS_TEMPERATURE_SET 0xb8
>> +#define MCS_PENTILE_CTRL 0xc0
>> +#define MCS_GAMMA_MODE 0xca
>> +#define MCS_VDDM 0xd7
>> +#define MCS_ALS 0xe3
>> +#define MCS_ERR_FG 0xed
>> +#define MCS_KEY_LEV1 0xf0
>> +#define MCS_GAMMA_UPDATE 0xf7
>> +#define MCS_KEY_LEV2 0xfc
>> +#define MCS_RE 0xfe
>> +#define MCS_TOUT2_HSYNC 0xff
>> +
>> +/* Content Adaptive Brightness Control */
>> +#define DCS_WRITE_CABC 0x55
>
> Is this not a manufacturer specific command? I couldn't find it in the
> DSI or DCS specifications, but it sounds like something standard (also
> indicated by the DCS_ prefix). Can you point out the specification for
> this?
>
Andrzej commented before and decided it as DCS one because if the value
is less than 0xb0, it is DCS one and the others are MCS one.
But still I'm not sure it is correct.
>> +#define MTP_ID_LEN 3
>> +#define GAMMA_LEVEL_NUM 30
>> +
>> +#define DEFAULT_VDDM_VAL 0x15
>> +
>> +struct s6e3fa0 {
>> + struct device *dev;
>> + struct drm_panel panel;
>> +
>> + struct regulator_bulk_data supplies[2];
>> + struct gpio_desc *reset_gpio;
>> + struct videomode vm;
>> +
>> + unsigned int power_on_delay;
>> + unsigned int reset_delay;
>> + unsigned int init_delay;
>> + unsigned int width_mm;
>> + unsigned int height_mm;
>> +
>> + unsigned char id;
>> + unsigned char vddm;
>> + unsigned int brightness;
>> +};
>
> Please don't use this kind of artificial padding. A simple space will
> do.
>
>> +
>> +#define panel_to_s6e3fa0(p) container_of(p, struct s6e3fa0, panel)
>
> Please turn this into a function so we can get proper type checking.
>
>> +
>> +/* VDD Memory Lookup Table contains pairs of {ReadValue, WriteValue} */
>> +static const unsigned char s6e3fa0_vddm_lut[][2] = {
>> + {0x00, 0x0d}, {0x01, 0x0d}, {0x02, 0x0e}, {0x03, 0x0f}, {0x04, 0x10},
>> + {0x05, 0x11}, {0x06, 0x12}, {0x07, 0x13}, {0x08, 0x14}, {0x09, 0x15},
>> + {0x0a, 0x16}, {0x0b, 0x17}, {0x0c, 0x18}, {0x0d, 0x19}, {0x0e, 0x1a},
>> + {0x0f, 0x1b}, {0x10, 0x1c}, {0x11, 0x1d}, {0x12, 0x1e}, {0x13, 0x1f},
>> + {0x14, 0x20}, {0x15, 0x21}, {0x16, 0x22}, {0x17, 0x23}, {0x18, 0x24},
>> + {0x19, 0x25}, {0x1a, 0x26}, {0x1b, 0x27}, {0x1c, 0x28}, {0x1d, 0x29},
>> + {0x1e, 0x2a}, {0x1f, 0x2b}, {0x20, 0x2c}, {0x21, 0x2d}, {0x22, 0x2e},
>> + {0x23, 0x2f}, {0x24, 0x30}, {0x25, 0x31}, {0x26, 0x32}, {0x27, 0x33},
>> + {0x28, 0x34}, {0x29, 0x35}, {0x2a, 0x36}, {0x2b, 0x37}, {0x2c, 0x38},
>> + {0x2d, 0x39}, {0x2e, 0x3a}, {0x2f, 0x3b}, {0x30, 0x3c}, {0x31, 0x3d},
>> + {0x32, 0x3e}, {0x33, 0x3f}, {0x34, 0x3f}, {0x35, 0x3f}, {0x36, 0x3f},
>> + {0x37, 0x3f}, {0x38, 0x3f}, {0x39, 0x3f}, {0x3a, 0x3f}, {0x3b, 0x3f},
>> + {0x3c, 0x3f}, {0x3d, 0x3f}, {0x3e, 0x3f}, {0x3f, 0x3f}, {0x40, 0x0c},
>> + {0x41, 0x0b}, {0x42, 0x0a}, {0x43, 0x09}, {0x44, 0x08}, {0x45, 0x07},
>> + {0x46, 0x06}, {0x47, 0x05}, {0x48, 0x04}, {0x49, 0x03}, {0x4a, 0x02},
>> + {0x4b, 0x01}, {0x4c, 0x40}, {0x4d, 0x41}, {0x4e, 0x42}, {0x4f, 0x43},
>> + {0x50, 0x44}, {0x51, 0x45}, {0x52, 0x46}, {0x53, 0x47}, {0x54, 0x48},
>> + {0x55, 0x49}, {0x56, 0x4a}, {0x57, 0x4b}, {0x58, 0x4c}, {0x59, 0x4d},
>> + {0x5a, 0x4e}, {0x5b, 0x4f}, {0x5c, 0x50}, {0x5d, 0x51}, {0x5e, 0x52},
>> + {0x5f, 0x53}, {0x60, 0x54}, {0x61, 0x55}, {0x62, 0x56}, {0x63, 0x57},
>> + {0x64, 0x58}, {0x65, 0x59}, {0x66, 0x5a}, {0x67, 0x5b}, {0x68, 0x5c},
>> + {0x69, 0x5d}, {0x6a, 0x5e}, {0x6b, 0x5f}, {0x6c, 0x60}, {0x6d, 0x61},
>> + {0x6e, 0x62}, {0x6f, 0x63}, {0x70, 0x64}, {0x71, 0x65}, {0x72, 0x66},
>> + {0x73, 0x67}, {0x74, 0x68}, {0x75, 0x69}, {0x76, 0x6a}, {0x77, 0x6b},
>> + {0x78, 0x6c}, {0x79, 0x6d}, {0x7a, 0x6e}, {0x7b, 0x6f}, {0x7c, 0x70},
>> + {0x7d, 0x71}, {0x7e, 0x72}, {0x7f, 0x73},
>> +};
>
> What's this used for?
>
This ldi contains an internal memory and requires an appropriate VDD.
Each panel stores OTP value for this vddm, so reads this value, finds
matching value with vddm_lut and writes the final value to avoid noise
issues from an inappropriate VDD.
>> +static int s6e3fa0_dcs_read(struct s6e3fa0 *ctx, unsigned char cmd,
>> + void *data, size_t len)
>> +{
>> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> +
>> + return mipi_dsi_dcs_read(dsi, dsi->channel, cmd, data, len);
>> +}
>> +
>> +static void s6e3fa0_dcs_write(struct s6e3fa0 *ctx, const void *data, size_t len)
>> +{
>> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> +
>> + mipi_dsi_dcs_write(dsi, dsi->channel, data, len);
>> +}
>
> Both mipi_dsi_dcs_read() and mipi_dsi_dcs_write() return error codes on
> failure. Why are you silently ignoring them?
>
>> +#define s6e3fa0_dcs_write_seq(ctx, seq...) \
>> +do { \
>> + const unsigned char d[] = { seq }; \
>> + BUILD_BUG_ON_MSG(ARRAY_SIZE(d) > 64, "too big seq for stack"); \
>> + s6e3fa0_dcs_write(ctx, d, ARRAY_SIZE(d)); \
>> +} while (0)
>> +
>> +#define s6e3fa0_dcs_write_seq_static(ctx, seq...) \
>> +do { \
>> + static const unsigned char d[] = { seq }; \
>> + s6e3fa0_dcs_write(ctx, d, ARRAY_SIZE(d)); \
>> +} while (0)
>
> I've had this discussion with Andrzej before and I'm still not convinced
> that this is a useful macro.
>
> At least they should propagate the error code, though.
>
>> +static void s6e3fa0_set_maximum_return_packet_size(struct s6e3fa0 *ctx,
>> + unsigned int size)
>> +{
>> + struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> + const struct mipi_dsi_host_ops *ops = dsi->host->ops;
>> +
>> + if (ops && ops->transfer) {
>> + unsigned char buf[] = {size, 0};
>> + struct mipi_dsi_msg msg = {
>> + .channel = dsi->channel,
>> + .type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
>> + .tx_len = sizeof(buf),
>> + .tx_buf = buf
>> + };
>> +
>> + ops->transfer(dsi->host, &msg);
>> + }
>> +}
>
> The Set Maximum Return Packet Size command is a standard command, so
> please turn that into a generic function exposed by the DSI core.
>
For this and below standard DCS commands, you want to use generic
functions, but I have no idea for that.
Could you explain more detail?
>> +static void s6e3fa0_read_mtp_id(struct s6e3fa0 *ctx)
>> +{
>> + unsigned char id[MTP_ID_LEN];
>> + int ret;
>> +
>> + s6e3fa0_set_maximum_return_packet_size(ctx, MTP_ID_LEN);
>> + ret = s6e3fa0_dcs_read(ctx, MIPI_DCS_GET_DISPLAY_ID, id, MTP_ID_LEN);
>
> This also looks like a standard DCS command. I can't find it in either
> v1.01 nor v1.02 of the specification, though. Do you know where it's
> specified?
>
Yes, I also can't find it in DCS specification and there is no special
description in panel datasheet.
But as it is declared in "include/video/mipi_display.h", so I think it
is a standard one.
Thank you.
Best regards YJ
>> +static void s6e3fa0_set_te_on(struct s6e3fa0 *ctx)
>> +{
>> + s6e3fa0_dcs_write_seq_static(ctx, MIPI_DCS_SET_TEAR_ON, 0x00);
>> +}
>
> This is also a standard DCS command.
>
>> +static int s6e3fa0_power_off(struct s6e3fa0 *ctx)
>> +{
>> + gpiod_set_value(ctx->reset_gpio, 0);
>
> Setting the reset GPIO to 0 for power off? Shouldn't this be 1 and the
> polarity be specified in the GPIO specifier?
>
>> +static void s6e3fa0_set_sequence(struct s6e3fa0 *ctx)
>> +{
>> + s6e3fa0_apply_level_1_key(ctx);
>> + s6e3fa0_dcs_write_seq_static(ctx, MIPI_DCS_EXIT_SLEEP_MODE);
>> + msleep(20);
>> +
>> + s6e3fa0_read_mtp_id(ctx);
>> + s6e3fa0_read_vddm(ctx);
>> +
>> + s6e3fa0_panel_init(ctx);
>> +
>> + s6e3fa0_dcs_write_seq_static(ctx, MIPI_DCS_SET_DISPLAY_ON);
>> +}
>> +
>> +static int s6e3fa0_disable(struct drm_panel *panel)
>> +{
>> + struct s6e3fa0 *ctx = panel_to_s6e3fa0(panel);
>> +
>> + s6e3fa0_dcs_write_seq_static(ctx, MIPI_DCS_SET_DISPLAY_OFF);
>> + msleep(35);
>> + s6e3fa0_dcs_write_seq_static(ctx, MIPI_DCS_ENTER_SLEEP_MODE);
>> + msleep(120);
>> +
>> + return s6e3fa0_power_off(ctx);
>> +}
>
> The SET_DISPLAY_{ON,OFF} and {ENTER,EXIT}_SLEEP_MODE are standard
> commands, too.
>
>> +static int s6e3fa0_probe(struct mipi_dsi_device *dsi)
>> +{
>> + struct device *dev = &dsi->dev;
>> + struct s6e3fa0 *ctx;
>> + struct gpio_desc *det_gpio;
>> + int ret, te_gpio;
>> +
>> + ctx = devm_kzalloc(dev, sizeof(struct s6e3fa0), GFP_KERNEL);
>
> sizeof(*ctx)
>
>> + det_gpio = devm_gpiod_get(dev, "det");
>> + if (IS_ERR(det_gpio)) {
>> + dev_err(dev, "failed to get det gpio: %ld\n",
>> + PTR_ERR(det_gpio));
>> + return PTR_ERR(det_gpio);
>> + }
>> + ret = gpiod_direction_input(det_gpio);
>> + if (ret < 0) {
>> + dev_err(dev, "failed to configure det gpio: %d\n", ret);
>> + return ret;
>> + }
>> + ret = devm_request_irq(dev, gpiod_to_irq(det_gpio),
>> + s6e3fa0_det_interrupt, IRQF_TRIGGER_FALLING,
>> + "oled-det", ctx);
>> + if (ret) {
>> + dev_err(dev, "failed to request det irq: %d\n", ret);
>> + return ret;
>> + }
>> +
>> + te_gpio = of_get_named_gpio(dev->of_node, "te-gpios", 0);
>
> Why doesn't this use the gpiod_* API like the other GPIOs?
>
>> +static struct of_device_id s6e3fa0_of_match[] = {
>
> Should be static const.
>
> Thierry
>
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