Hi Sam,

  Thanks for your comments, i will rework this panel driver after l3gd20
patch submission.

Sam Ravnborg <sam@ravnborg.org> 于2020年5月8日周五 下午5:02写道：

> Hi Dillon.
>
> Patch submissions starts to look fine.
>
> On Fri, May 08, 2020 at 12:13:14PM +0800, dillon.minfei@gmail.com wrote:
> > From: dillon min <dillon.minfei@gmail.com>
> >
> > This is a driver for 320x240 TFT panels, accepting a rgb input
> > streams that get adapted and scaled to the panel.
> This driver is, I suppose, prepared to be a driver for ILI9341 based
> panles, and as such not for a fixed resolution.
> I expect (hope) we in the future will see more panels added.
>
> As i checked ili9341 datasheets, this panel just support 240x320
resolution only.  if i'm wrong , please correct me. thanks
https://cdn-shop.adafruit.com/datasheets/ILI9341.pdf

This panel can support 9 different kinds of interface , "3/4-line Serial
Interface" have been supported by tiny/ili9341.c. i was verified it
but the performance on stm32f4 is very low.

currently, i just have stm32f429-disco in hands, with 18-bit parallel rgb
bus connected on this board. reference to panel-ilitek-ili9322 and
panel-ilitek-ili9881 driver, i have some plan to rewrite this driver.

1 add your below comments in.
2 use dc-gpio, reset-gpio, rgb-interface-bits from dts to config panel
interface.
3 drop regmap, porting drm_mipi_dbi's mipi_dbi_command to config panel
paramter. like tiny/ili9341.c
4 support rgb-16, rgb-18 interface.
5 use optional regulator or power gpio to control panel's power, as panel
power is always on for my board, so i can't test this part. could i add the
code which can't be tested?
6 support rotation in panel config (currently , i rotate the screen by
kernel cmdline paramter)

if you have any other common panel configuration should be add , please
inform me.

thanks.

>
> Some things to fix, see comments in the follwoing.
>
>         Sam
>
> >
> > Signed-off-by: dillon min <dillon.minfei@gmail.com>
> > ---
> >  drivers/gpu/drm/panel/Kconfig                |   8 +
> >  drivers/gpu/drm/panel/Makefile               |   1 +
> >  drivers/gpu/drm/panel/panel-ilitek-ili9341.c | 561
> +++++++++++++++++++++++++++
> >  3 files changed, 570 insertions(+)
> >  create mode 100644 drivers/gpu/drm/panel/panel-ilitek-ili9341.c
> >
> > diff --git a/drivers/gpu/drm/panel/Kconfig
> b/drivers/gpu/drm/panel/Kconfig
> > index a1723c1..e42692c 100644
> > --- a/drivers/gpu/drm/panel/Kconfig
> > +++ b/drivers/gpu/drm/panel/Kconfig
> > @@ -95,6 +95,14 @@ config DRM_PANEL_ILITEK_IL9322
> >         Say Y here if you want to enable support for Ilitek IL9322
> >         QVGA (320x240) RGB, YUV and ITU-T BT.656 panels.
> >
> > +config DRM_PANEL_ILITEK_IL9341
> ILI9341 - so the config name matches the name of the driver IC.
>
> > +     tristate "Ilitek ILI9341 240x320 QVGA panels"
> > +     depends on OF && SPI
> > +     select REGMAP
> > +     help
> > +       Say Y here if you want to enable support for Ilitek IL9341
> > +       QVGA (240x320) RGB panels.
> See comment to the changelog, the driver is more generic - I assume.
> So the wording here can be improved to express this.
>
> Add support RGB 16bits and RGB 18bits bus only ?

> > +
> >  config DRM_PANEL_ILITEK_ILI9881C
> >       tristate "Ilitek ILI9881C-based panels"
> >       depends on OF
> > diff --git a/drivers/gpu/drm/panel/Makefile
> b/drivers/gpu/drm/panel/Makefile
> > index 96a883c..d123543 100644
> > --- a/drivers/gpu/drm/panel/Makefile
> > +++ b/drivers/gpu/drm/panel/Makefile
> > @@ -8,6 +8,7 @@ obj-$(CONFIG_DRM_PANEL_ELIDA_KD35T133) +=
> panel-elida-kd35t133.o
> >  obj-$(CONFIG_DRM_PANEL_FEIXIN_K101_IM2BA02) +=
> panel-feixin-k101-im2ba02.o
> >  obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) +=
> panel-feiyang-fy07024di26a30d.o
> >  obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
> > +obj-$(CONFIG_DRM_PANEL_ILITEK_IL9341) += panel-ilitek-ili9341.o
> >  obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
> >  obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
> >  obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
> > diff --git a/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
> b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
> > new file mode 100644
> > index 0000000..ec22d80
> > --- /dev/null
> > +++ b/drivers/gpu/drm/panel/panel-ilitek-ili9341.c
> > @@ -0,0 +1,561 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Ilitek ILI9341 TFT LCD drm_panel driver.
> > + *
> > + * This panel can be configured to support:
> > + * - 16-bit parallel RGB interface
> The interface to ILI9341 is SPI, and the interface between the ILI9341
> and the panel is more of an itnernal thing. Or did I get this worng?
>
> SPI is for register configuration.  RGB parallel for data transfer

> + *
> > + * Copyright (C) 2020 Dillon Min <dillon.minfei@gmail.com>
> > + * Derived from drivers/drm/gpu/panel/panel-ilitek-ili9322.c
> > + */
> > +
> > +#include <linux/bitops.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/regmap.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/spi/spi.h>
> > +
> > +#include <video/mipi_display.h>
> > +#include <video/of_videomode.h>
> > +#include <video/videomode.h>
> > +
> > +#include <drm/drm_modes.h>
> > +#include <drm/drm_panel.h>
> > +#include <drm/drm_print.h>
> > +
> > +#define DEFAULT_SPI_SPEED    10000000
> > +
>
> Please use same case for hex numbers in the driver.
> My personal preferences is lower-case.
>
> in next patch, spi speed will be configured by dts, not hardcode here.
below register address will change to lower-case hex numbers.


> > +#define ILI9341_SLEEP_OUT            0x11   /* Sleep out register */
> > +#define ILI9341_GAMMA                0x26   /* Gamma register */
> > +#define ILI9341_DISPLAY_OFF          0x28   /* Display off register */
> > +#define ILI9341_DISPLAY_ON           0x29   /* Display on register */
> > +#define ILI9341_COLUMN_ADDR          0x2A   /* Colomn address register
> */
> > +#define ILI9341_PAGE_ADDR            0x2B   /* Page address register */
> > +#define ILI9341_GRAM                 0x2C   /* GRAM register */
> > +#define ILI9341_MAC                  0x36   /* Memory Access Control
> register*/
> > +#define ILI9341_PIXEL_FORMAT         0x3A   /* Pixel Format register */
> > +#define ILI9341_WDB                  0x51   /* Write Brightness Display
> > +                                          * register
> > +                                          */
> > +#define ILI9341_WCD                  0x53   /* Write Control Display
> > +                                          * register
> > +                                          */
> > +#define ILI9341_RGB_INTERFACE        0xB0   /* RGB Interface Signal
> Control */
> > +#define ILI9341_FRC                  0xB1   /* Frame Rate Control
> register */
> > +#define ILI9341_BPC                  0xB5   /* Blanking Porch Control
> > +                                          * register
> > +                                          */
> > +#define ILI9341_DFC                  0xB6   /* Display Function Control
> > +                                          * register
> > +                                          */
> > +#define ILI9341_POWER1               0xC0   /* Power Control 1 register
> */
> > +#define ILI9341_POWER2               0xC1   /* Power Control 2 register
> */
> > +#define ILI9341_VCOM1                0xC5   /* VCOM Control 1 register
> */
> > +#define ILI9341_VCOM2                0xC7   /* VCOM Control 2 register
> */
> > +#define ILI9341_POWERA               0xCB   /* Power control A register
> */
> > +#define ILI9341_POWERB               0xCF   /* Power control B register
> */
> > +#define ILI9341_PGAMMA               0xE0   /* Positive Gamma Correction
> > +                                          * register
> > +                                          */
> > +#define ILI9341_NGAMMA               0xE1   /* Negative Gamma Correction
> > +                                          * register
> > +                                          */
> > +#define ILI9341_DTCA                 0xE8   /* Driver timing control A
> */
> > +#define ILI9341_DTCB                 0xEA   /* Driver timing control B
> */
> > +#define ILI9341_POWER_SEQ            0xED   /* Power on sequence
> register */
> > +#define ILI9341_3GAMMA_EN            0xF2   /* 3 Gamma enable register
> */
> > +#define ILI9341_INTERFACE            0xF6   /* Interface control
> register */
> > +#define ILI9341_PRC                  0xF7   /* Pump ratio control
> register */
> > +
>
> All the following should be const.
>
ok


> Can any of the below be replaces by DEFINED constants?
> > +static u8 ili9341_cmd0[] = {0xc3, 0x08, 0x50};
> > +static u8 ili9341_powerb[] = {0x00, 0xc1, 0x30};
> > +static u8 ili9341_power_seq[] = {0x64, 0x03, 0x12, 0x81};
> > +static u8 ili9341_dtca[] = {0x85, 0x00, 0x78};
> > +static u8 ili9341_powera[] = {0x39, 0x2c, 0x00, 0x34, 0x02};
> > +static u8 ili9341_prc[] = {0x20};
> > +static u8 ili9341_dtcb[] = {0x00, 0x00};
> > +static u8 ili9341_frc[] = {0x00, 0x1b};
> > +static u8 ili9341_dfc1[] = {0x0a, 0xa2};
> > +static u8 ili9341_power1[] = {0x10};
> > +static u8 ili9341_power2[] = {0x10};
> > +static u8 ili9341_vcom1[] = {0x45, 0x15};
> > +static u8 ili9341_vcom2[] = {0x90};
> > +static u8 ili9341_mac[] = {0xc8};
> > +static u8 ili9341_gamma_en[] = {0x00};
> > +static u8 ili9341_rgb_intr[] = {0xc2};
> > +static u8 ili9341_dfc2[] = {0x0a, 0xa7, 0x27, 0x04};
> > +static u8 ili9341_column_addr[] = {0x00, 0x00, 0x00, 0xef};
> > +static u8 ili9341_page_addr[] = {0x00, 0x00, 0x01, 0x3f};
> > +static u8 ili9341_intr[] = {0x01, 0x00, 0x06};
> > +static u8 ili9341_gamma[] = {0x01};
> > +static u8 ili9341_pgamma[] = {0x0f, 0x29, 0x24, 0x0c, 0x0e, 0x09, 0x4e,
> 0x78,
> > +                             0x3c, 0x09, 0x13, 0x05, 0x17, 0x11, 0x00};
> > +static u8 ili9341_ngamma[] = {0x00, 0x16, 0x1b, 0x04, 0x11, 0x07, 0x31,
> 0x33,
> > +                             0x42, 0x05, 0x0c, 0x0a, 0x28, 0x2f, 0x0f};
> > +
> > +/**
> > + * enum ili9341_input - the format of the incoming signal to the panel
> > + *
> > + * The panel can be connected to various input streams and four of them
> can
> > + * be selected by electronic straps on the display. However it is
> possible
> > + * to select another mode or override the electronic default with this
> > + * setting.
> > + */
> > +enum ili9341_input {
> > +     ILI9341_INPUT_PRGB_THROUGH = 0x0,
> > +     ILI9341_INPUT_PRGB_ALIGNED = 0x1,
> > +     ILI9341_INPUT_UNKNOWN = 0xf,
> > +};
> > +
> > +/**
> > + * struct ili9341_config - the system specific ILI9341 configuration
> > + * @width_mm: physical panel width [mm]
> > + * @height_mm: physical panel height [mm]
> > + * @input: the input/entry type used in this system, if this is set to
> > + * ILI9341_INPUT_UNKNOWN the driver will try to figure it out by probing
> > + * the hardware
> > + * @dclk_active_high: data/pixel clock active high, data will be clocked
> > + * in on the rising edge of the DCLK (this is usually the case).
> > + * @de_active_high: DE (data entry) is active high
> > + * @hsync_active_high: HSYNC is active high
> > + * @vsync_active_high: VSYNC is active high
> > + */
> > +struct ili9341_config {
> > +     u32 width_mm;
> > +     u32 height_mm;
> > +     enum ili9341_input input;
> > +     bool dclk_active_high;
> > +     bool de_active_high;
> > +     bool hsync_active_high;
> > +     bool vsync_active_high;
> > +};
> > +
> > +struct ili9341 {
> > +     struct device *dev;
> > +     const struct ili9341_config *conf;
> > +     struct drm_panel panel;
> > +     struct regmap *regmap;
> > +     struct gpio_desc *reset_gpio;
> > +     struct gpio_desc *dc_gpio;
> > +     enum ili9341_input input;
>
> > +     struct videomode vm;
> videomode is not used. So drop this field and drop the include files
> that are no logner needed.
>
> ok

> > +};
> > +
> > +static inline struct ili9341 *panel_to_ili9341(struct drm_panel *panel)
> > +{
> > +     return container_of(panel, struct ili9341, panel);
> > +}
> > +
> > +int ili9341_spi_transfer(struct spi_device *spi, u32 speed_hz,
> > +                       u8 bpw, const void *buf, size_t len)
> > +{
> > +     size_t max_chunk = spi_max_transfer_size(spi);
> > +     struct spi_transfer tr = {
> const?
>
> ok

> > +             .bits_per_word = bpw,
> > +             .speed_hz = speed_hz,
> > +             .len = len,
> > +     };
> > +     struct spi_message m;
> > +     size_t chunk;
> > +     int ret;
> > +
> > +     spi_message_init_with_transfers(&m, &tr, 1);
> > +
> > +     while (len) {
> > +             chunk = min(len, max_chunk);
> > +
> > +             tr.tx_buf = buf;
> > +             tr.len = chunk;
> > +             buf += chunk;
> > +             len -= chunk;
> > +
> > +             ret = spi_sync(spi, &m);
> > +             if (ret)
> > +                     return ret;
> > +     }
> > +     return 0;
> > +}
> > +static int ili9341_regmap_spi_write(void *context, const void *data,
> > +                                 size_t count)
> > +{
> > +     struct device *dev = context;
> > +     struct spi_device *spi = to_spi_device(dev);
> > +     struct ili9341 *ili = spi_get_drvdata(spi);
> > +     int ret = 0;
> > +
> > +     gpiod_set_value_cansleep(ili->dc_gpio, 0);
> > +
> > +     ret = ili9341_spi_transfer(spi, DEFAULT_SPI_SPEED, 8, data+0, 1);
> > +     if (ret || count == 1 ||
> > +                     ((u8 *)data)[0] == ILI9341_GRAM ||
> > +                     ((u8 *)data)[0] == ILI9341_DISPLAY_ON ||
> > +                     ((u8 *)data)[0] == ILI9341_SLEEP_OUT ||
> > +                     ((u8 *)data)[0] == ILI9341_DISPLAY_OFF)
> > +             return ret;
> > +
> > +     gpiod_set_value_cansleep(ili->dc_gpio, 1);
> > +
> > +     return ili9341_spi_transfer(spi, DEFAULT_SPI_SPEED, 8, data+1,
> count-1);
> > +}
> > +
> > +static int ili9341_regmap_spi_read(void *context, const void *reg,
> > +                                size_t reg_size, void *val, size_t
> val_size)
> > +{
> > +     return 0;
> > +}
> Is this function really needed? If not delete it.
>
> regmap will be drop in next patch.

> > +
> > +static struct regmap_bus ili9341_regmap_bus = {
> > +     .write = ili9341_regmap_spi_write,
> > +     .read = ili9341_regmap_spi_read,
> > +     .reg_format_endian_default = REGMAP_ENDIAN_BIG,
> > +     .val_format_endian_default = REGMAP_ENDIAN_BIG,
> > +};
> > +
> > +static bool ili9341_volatile_reg(struct device *dev, unsigned int reg)
> > +{
> > +     return false;
> > +}
> Is this function really nedded? If not delete it.
>
> > +
> > +static bool ili9341_writeable_reg(struct device *dev, unsigned int reg)
> > +{
> > +     /* Just register 0 is read-only */
> > +     if (reg == 0x00)
> > +             return false;
> > +     return true;
> > +}
> > +
> > +static const struct regmap_config ili9341_regmap_config = {
> > +     .reg_bits = 8,
> > +     .val_bits = 8,
> > +     .max_register = 0xff,
> > +     .cache_type = REGCACHE_RBTREE,
> > +     .volatile_reg = ili9341_volatile_reg,
> > +     .writeable_reg = ili9341_writeable_reg,
> > +};
> > +
>
> No error checks - consider something like:
>
> static int bulk_write(struct ili9341 *ili, u8 reg, const u8[] data, int
> len)
> {
>         int err = ili->err;
>
>         if (!err) {
>                 err = regmap_bulk_write(ili->regmap, reg, data, len);
>                 if (err) {
>                         dev_err(...);
>                         ili->err = err;
>                 }
>         }
>
>         return err;
> }
>
> Then you can use this in the following, and make this more readable.
>
> ok, thanks for detail guide.


> > +static int ili9341_init(struct drm_panel *panel, struct ili9341 *ili)
> > +{
> > +     regmap_bulk_write(ili->regmap, 0xca,
> > +                                     ili9341_cmd0,
> sizeof(ili9341_cmd0));
> > +     regmap_bulk_write(ili->regmap, ILI9341_POWERB,
> > +                             ili9341_powerb, sizeof(ili9341_powerb));
> > +     regmap_bulk_write(ili->regmap, ILI9341_POWER_SEQ,
> > +                             ili9341_power_seq,
> sizeof(ili9341_power_seq));
> > +     regmap_bulk_write(ili->regmap, ILI9341_DTCA,
> > +                             ili9341_dtca, sizeof(ili9341_dtca));
> > +     regmap_bulk_write(ili->regmap, ILI9341_POWERA,
> > +                             ili9341_powera, sizeof(ili9341_powera));
> > +     regmap_write(ili->regmap, ILI9341_PRC, ili9341_prc[0]);
> > +     regmap_bulk_write(ili->regmap, ILI9341_DTCB,
> > +                             ili9341_dtcb, sizeof(ili9341_dtcb));
> > +     regmap_bulk_write(ili->regmap, ILI9341_FRC,
> > +                             ili9341_frc, sizeof(ili9341_frc));
> > +     regmap_bulk_write(ili->regmap, ILI9341_DFC,
> > +                             ili9341_dfc1, sizeof(ili9341_dfc1));
> > +     regmap_write(ili->regmap, ILI9341_POWER1, ili9341_power1[0]);
> > +     regmap_write(ili->regmap, ILI9341_POWER2, ili9341_power2[0]);
> > +     regmap_bulk_write(ili->regmap, ILI9341_VCOM1,
> > +                             ili9341_vcom1, sizeof(ili9341_vcom1));
> > +     regmap_write(ili->regmap, ILI9341_VCOM2, ili9341_vcom2[0]);
> > +     regmap_write(ili->regmap, ILI9341_MAC, ili9341_mac[0]);
> > +     regmap_write(ili->regmap, ILI9341_3GAMMA_EN, ili9341_gamma_en[0]);
> > +     regmap_write(ili->regmap, ILI9341_RGB_INTERFACE,
> ili9341_rgb_intr[0]);
> > +     regmap_bulk_write(ili->regmap, ILI9341_DFC,
> > +                             ili9341_dfc2, sizeof(ili9341_dfc2));
> > +
> > +     /* colomn address set */
> > +     regmap_bulk_write(ili->regmap, ILI9341_COLUMN_ADDR,
> > +                     ili9341_column_addr, sizeof(ili9341_column_addr));
> > +
> > +     /* Page Address Set */
> > +     regmap_bulk_write(ili->regmap, ILI9341_PAGE_ADDR,
> > +                             ili9341_page_addr,
> sizeof(ili9341_page_addr));
> > +     regmap_bulk_write(ili->regmap, ILI9341_INTERFACE,
> > +                             ili9341_intr, sizeof(ili9341_intr));
> > +     regmap_write(ili->regmap, ILI9341_GRAM, 0);
> > +     msleep(200);
> > +
> > +     regmap_write(ili->regmap, ILI9341_GAMMA, ili9341_gamma[0]);
> > +     regmap_bulk_write(ili->regmap, ILI9341_PGAMMA,
> > +                             ili9341_pgamma, sizeof(ili9341_pgamma));
> > +     regmap_bulk_write(ili->regmap, ILI9341_NGAMMA,
> > +                             ili9341_ngamma, sizeof(ili9341_ngamma));
> > +     regmap_write(ili->regmap, ILI9341_SLEEP_OUT, 0);
> > +     msleep(200);
> > +
> > +     regmap_write(ili->regmap, ILI9341_DISPLAY_ON, 0);
> > +
> > +     /* GRAM start writing */
> > +     regmap_write(ili->regmap, ILI9341_GRAM, 0);
> > +
> > +     dev_info(ili->dev, "initialized display\n");
> > +
> > +     return 0;
> > +}
> > +
> > +/*
> > + * This power-on sequence if from the datasheet, page 57.
> > + */
> > +static int ili9341_power_on(struct ili9341 *ili)
> > +{
> > +     /* Assert RESET */
> > +     gpiod_set_value(ili->reset_gpio, 1);
> > +
> > +     msleep(20);
> > +
> > +     /* De-assert RESET */
> > +     gpiod_set_value(ili->reset_gpio, 0);
> > +
> > +     msleep(10);
> > +
> > +     return 0;
> > +}
> > +
> > +static int ili9341_power_off(struct ili9341 *ili)
> > +{
>
>         Assert reset?
> will add reset-pin control here.
>


> > +     return 0;
> > +}
> > +
> > +static int ili9341_disable(struct drm_panel *panel)
> > +{
> > +     struct ili9341 *ili = panel_to_ili9341(panel);
> > +     int ret;
> > +
> > +     ret = regmap_write(ili->regmap, ILI9341_DISPLAY_OFF, 0);
> > +     if (ret) {
> > +             dev_err(ili->dev, "unable to go to standby mode\n");
> > +             return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +static int ili9341_unprepare(struct drm_panel *panel)
> > +{
> > +     struct ili9341 *ili = panel_to_ili9341(panel);
> > +
> > +     return ili9341_power_off(ili);
> > +}
> > +
> > +static int ili9341_prepare(struct drm_panel *panel)
> > +{
> > +     struct ili9341 *ili = panel_to_ili9341(panel);
> > +     int ret;
> > +
> > +     ret = ili9341_power_on(ili);
> > +     if (ret < 0)
> > +             return ret;
> > +
> > +     ret = ili9341_init(panel, ili);
> > +     if (ret < 0)
> > +             ili9341_unprepare(panel);
> > +
> > +     return ret;
> > +}
> > +
> > +static int ili9341_enable(struct drm_panel *panel)
> > +{
> > +     struct ili9341 *ili = panel_to_ili9341(panel);
> > +     int ret;
> > +
> > +     ret = regmap_write(ili->regmap, ILI9341_DISPLAY_ON, 0);
> > +     if (ret) {
> > +             dev_err(ili->dev, "unable to enable panel\n");
> > +             return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> > +/* This is the only mode listed for parallel RGB in the datasheet */
> > +static const struct drm_display_mode prgb_320x240_mode = {
> > +     .clock = 6100,
> > +     .hdisplay = 240,
> > +     .hsync_start = 240 + 10,
> > +     .hsync_end = 240 + 10 + 10,
> > +     .htotal = 280,
> > +     .vdisplay = 320,
> > +     .vsync_start = 320 + 4,
> > +     .vsync_end = 320 + 4 + 2,
> > +     .vtotal = 328,
> > +     .vrefresh = 60,
> > +     .flags = 0,
> > +};
> > +
> > +static int ili9341_get_modes(struct drm_panel *panel,
> > +                             struct drm_connector *connector)
> > +{
> > +     struct ili9341 *ili = panel_to_ili9341(panel);
> > +     struct drm_device *drm = connector->dev;
> > +     struct drm_display_mode *mode;
> > +     struct drm_display_info *info;
> > +
> > +     info = &connector->display_info;
> > +     info->width_mm = ili->conf->width_mm;
> > +     info->height_mm = ili->conf->height_mm;
> > +     if (ili->conf->dclk_active_high)
> > +             info->bus_flags |= DRM_BUS_FLAG_PIXDATA_DRIVE_POSEDGE;
> > +     else
> > +             info->bus_flags |= DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
> > +
> > +     if (ili->conf->de_active_high)
> > +             info->bus_flags |= DRM_BUS_FLAG_DE_HIGH;
> > +     else
> > +             info->bus_flags |= DRM_BUS_FLAG_DE_LOW;
> > +
> > +     switch (ili->input) {
> > +     case ILI9341_INPUT_PRGB_THROUGH:
> > +     case ILI9341_INPUT_PRGB_ALIGNED:
> > +             mode = drm_mode_duplicate(drm, &prgb_320x240_mode);
> > +             break;
> > +     default:
> > +             mode = NULL;
> > +             break;
> > +     }
> > +     if (!mode) {
> > +             DRM_ERROR("bad mode or failed to add mode\n");
> > +             return -EINVAL;
> > +     }
> > +     drm_mode_set_name(mode);
> > +     /*
> > +      * This is the preferred mode because most people are going
> > +      * to want to use the display with VGA type graphics.
> > +      */
> > +     mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> > +
> > +     /* Set up the polarity */
> > +     if (ili->conf->hsync_active_high)
> > +             mode->flags |= DRM_MODE_FLAG_PHSYNC;
> > +     else
> > +             mode->flags |= DRM_MODE_FLAG_NHSYNC;
> > +     if (ili->conf->vsync_active_high)
> > +             mode->flags |= DRM_MODE_FLAG_PVSYNC;
> > +     else
> > +             mode->flags |= DRM_MODE_FLAG_NVSYNC;
> > +
> > +     mode->width_mm = ili->conf->width_mm;
> > +     mode->height_mm = ili->conf->height_mm;
> > +     drm_mode_probed_add(connector, mode);
> > +
> > +     return 1; /* Number of modes */
> > +}
> > +
> > +static const struct drm_panel_funcs ili9341_drm_funcs = {
> > +     .disable = ili9341_disable,
> > +     .unprepare = ili9341_unprepare,
> > +     .prepare = ili9341_prepare,
> > +     .enable = ili9341_enable,
> > +     .get_modes = ili9341_get_modes,
> > +};
> > +
> > +static int ili9341_probe(struct spi_device *spi)
> > +{
> > +     struct device *dev = &spi->dev;
> > +     struct ili9341 *ili;
> > +     const struct regmap_config *regmap_config;
> > +     int ret;
> > +
> > +     ili = devm_kzalloc(dev, sizeof(struct ili9341), GFP_KERNEL);
> > +     if (!ili)
> > +             return -ENOMEM;
> > +
> > +     spi_set_drvdata(spi, ili);
> > +
> > +     ili->dev = dev;
> > +     /*
> > +      * Every new incarnation of this display must have a unique
> > +      * data entry for the system in this driver.
> > +      */
> > +     ili->conf = of_device_get_match_data(dev);
> > +     if (!ili->conf) {
> > +             dev_err(dev, "missing device configuration\n");
> > +             return -ENODEV;
> > +     }
> > +
> > +     ili->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> GPIOD_OUT_HIGH);
> > +     if (IS_ERR(ili->reset_gpio)) {
> > +             dev_err(dev, "failed to get RESET GPIO\n");
> > +             return PTR_ERR(ili->reset_gpio);
> > +     }
> > +
> > +     ili->dc_gpio = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
> > +     if (IS_ERR(ili->dc_gpio)) {
> > +             dev_err(dev, "failed to get DC GPIO\n");
> > +             return PTR_ERR(ili->dc_gpio);
> > +     }
> > +
> > +     spi->bits_per_word = 8;
> > +     ret = spi_setup(spi);
> > +     if (ret < 0) {
> > +             dev_err(dev, "spi setup failed.\n");
> > +             return ret;
> > +     }
> > +
> > +     regmap_config = &ili9341_regmap_config;
> > +
> > +     ili->regmap = devm_regmap_init(dev, &ili9341_regmap_bus, dev,
> > +                                    regmap_config);
> > +     if (IS_ERR(ili->regmap)) {
> > +             dev_err(dev, "failed to allocate register map\n");
> > +             return PTR_ERR(ili->regmap);
> > +     }
> > +
> > +     ili->input = ili->conf->input;
> > +
> > +     drm_panel_init(&ili->panel, dev, &ili9341_drm_funcs,
> > +                    DRM_MODE_CONNECTOR_DPI);
> > +
> > +     return drm_panel_add(&ili->panel);
> > +}
> > +
> > +static int ili9341_remove(struct spi_device *spi)
> > +{
> > +     struct ili9341 *ili = spi_get_drvdata(spi);
> > +
> > +     ili9341_power_off(ili);
> > +     drm_panel_remove(&ili->panel);
> > +
> > +     return 0;
> > +}
> > +
> > +/*
> > + * The Stm32f429-disco board has a panel ili9341 connected to ltdc
> controller
> > + */
> > +static const struct ili9341_config ili9341_data = {
> This should be named "disco" something as this is m32f429-disco
> specific.
>
> ok

> > +     .width_mm = 65,
> > +     .height_mm = 50,
> > +     .input = ILI9341_INPUT_PRGB_THROUGH,
> > +     .dclk_active_high = true,
> > +     .de_active_high = false,
> > +     .hsync_active_high = false,
> > +     .vsync_active_high = false,
> > +};
> > +
> > +static const struct of_device_id ili9341_of_match[] = {
> > +     {
> > +             .compatible = "stm32f429,ltdc-panel",
> > +             .data = &ili9341_data,
> > +     },
>
>
> > +     {
> > +             .compatible = "ilitek,ili9341",
> > +             .data = NULL,
> This part is wrong, as ilitek,ili9341 is just the generic part.
> Only the first entry is relevant.
>
>
> ok

> > +     },
> > +     { }
> > +};
> > +MODULE_DEVICE_TABLE(of, ili9341_of_match);
> > +
> > +static struct spi_driver ili9341_driver = {
> > +     .probe = ili9341_probe,
> > +     .remove = ili9341_remove,
> > +     .driver = {
> > +             .name = "panel-ilitek-ili9341",
> > +             .of_match_table = ili9341_of_match,
> > +     },
> > +};
> > +module_spi_driver(ili9341_driver);
> > +
> > +MODULE_AUTHOR("Dillon Min <dillon.minfei@gmail.com>");
> > +MODULE_DESCRIPTION("ILI9341 LCD panel driver");
> > +MODULE_LICENSE("GPL v2");
> > --
> > 2.7.4
>