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st7735s: add (step 2) initialization of display st7735s
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Signed-off-by: Andrey Pahomov <[email protected]>
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@pahomov-and
pahomov-and committed Jan 20, 2020
1 parent a731247 commit 3a4efb5
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Showing 2 changed files with 309 additions and 12 deletions.
300 changes: 299 additions & 1 deletion st7735s/st7735s.c
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Original file line number Diff line number Diff line change
Expand Up @@ -9,21 +9,317 @@
#include <linux/device.h>
#include <linux/err.h>
#include <linux/spi/spi.h>
#include <linux/gpio/consumer.h>
#include <linux/delay.h>
#include <linux/of.h>

#define ST7735S_MADCTL_RGB 0x00
#define ST7735S_MADCTL_BGR 0x08
#define ST7735S_MADCTL_MY 0x80
#define ST7735S_MADCTL_MX 0x40

#define ST7735S_IS_160X128 1
#define ST7735S_WIDTH 128
#define ST7735S_HEIGHT 160
#define ST7735S_XSTART 0
#define ST7735S_YSTART 0
#define ST7735S_ROTATION (ST7735S_MADCTL_MX | ST7735S_MADCTL_MY)

// Pins
#define ST7735S_PIN_CS 67
#define ST7735S_PIN_RESET 2
#define ST7735S_PIN_DC 71

// Commands
#define ST7735S_SWRESET 0x01 // SoftWare Reset
#define ST7735S_SLPOUT 0x11 // Sleep Out
#define ST7735S_FRMCTR1 0xB1 // Norman Mode (Full colors)
#define ST7735S_FRMCTR2 0xB2 // In idle Mode (8 colors)
#define ST7735S_FRMCTR3 0xB3 // In partial Mode + Full Colors
#define ST7735S_INVCTR 0xB4 // Display inversion control
#define ST7735S_PWCTR1 0xC0 // Power control setting
#define ST7735S_PWCTR2 0xC1 // Power control setting
#define ST7735S_PWCTR3 0xC2 // In normal mode (Full colors)
#define ST7735S_PWCTR4 0xC3 // In idle mode (8 colors)
#define ST7735S_PWCTR5 0xC4 // In partial mode + Full colors
#define ST7735S_VMCTR1 0xC5 // VCOM control 1
#define ST7735S_INVOFF 0x20 // Display inversion off
#define ST7735S_MADCTL 0x36 // Memory data access control
#define ST7735S_COLMOD 0x3A // Interface pixel format
#define ST7735S_CASET 0x2A
#define ST7735S_RASET 0x2B
#define ST7735S_GMCTRP1 0xE0
#define ST7735S_GMCTRN1 0xE1
#define ST7735S_NORON 0x13
#define ST7735S_DISPON 0x29
#define ST7735S_DISPOFF 0x28
#define ST7735S_RAMWR 0x2C

#define DELAY 0x80




struct Tst7735s_info {
struct spi_device *spi;
struct gpio_desc *dc_gpio;
struct gpio_desc *reset_gpio;
};


static struct Tst7735s_info st7735s_info;
static u16 frame_buffer[ST7735S_WIDTH * ST7735S_HEIGHT];

////////////////////////////////////////////////////////////////////////////////

static const u8 init_cmds1[] = {
// Init for st7735s, part 1 (red or green tab)
15,// 15 commands in list:
ST7735S_SWRESET, DELAY,//1: Software reset, 0 args, w/delay
150,//150 ms delay
ST7735S_SLPOUT, DELAY,// 2: Out of sleep mode, 0 args, w/delay
255,//255 ms delay
ST7735S_FRMCTR1, 3,//3: Frame rate ctrl - normal mode, 3 args:
0x02, 0x2D, 0x2E,//Rate = fosc/(0x02+40) * (LINE+2D+2E)
ST7735S_FRMCTR2, 3,//4: Frame rate control - idle mode, 3 args:
0x02, 0x2D, 0x2E,//Rate = fosc/(0x02+40) * (LINE+2D+2E)
ST7735S_FRMCTR3, 6,//5: Frame rate ctrl - partial mode, 6 args:
0x02, 0x2D, 0x2E,//Dot inversion mode
0x02, 0x2D, 0x2E,//Line inversion mode
ST7735S_INVCTR, 1,// 6: Display inversion ctrl, 1 arg, no delay:
0x07,//No inversion
ST7735S_PWCTR1, 3,// 7: Power control, 3 args, no delay:
0xA2,
0x02,//-4.6V
0x84,//AUTO mode
ST7735S_PWCTR2, 1,// 8: Power control, 1 arg, no delay:
0xC5,//VGH25 = 2.4C VGSEL = -10 VGH = 3 * AVDD
ST7735S_PWCTR3, 2,// 9: Power control, 2 args, no delay:
0x0A,//Opamp current small
0x00,//Boost frequency
ST7735S_PWCTR4, 2,//10: Power control, 2 args, no delay:
0x8A,//BCLK/2, Opamp current small & Medium low
0x2A,
ST7735S_PWCTR5, 2,// 11: Power control, 2 args, no delay:
0x8A, 0xEE,
ST7735S_VMCTR1, 1,// 12:Power control, 1 arg, no delay:
0x0E,
ST7735S_INVOFF, 0,//13:Don't invert display, no args, no delay
ST7735S_MADCTL, 1,//14:Memory access control (directions),1arg:
ST7735S_ROTATION,//row addr/col addr, bottom to top refresh
ST7735S_COLMOD, 1,//15: set color mode, 1 arg, no delay:
0x05
}, // 16-bit color

init_cmds2[] = {
// Init for st7735s, part 2
2,// 2 commands in list:
ST7735S_CASET, 4,//1: Column addr set, 4 args, no delay:
0x00, 0x00,//XSTART = 0
0x00, 0x7F,//XEND = 127
ST7735S_RASET, 4,//2: Row addr set, 4 args, no delay:
0x00, 0x00,//XSTART = 0
0x00, 0x9F
},

init_cmds3[] = {
//Init for st7735s, part 3
4,// 4 commands in list:
ST7735S_GMCTRP1, 16,//1:Magical unicorn dust, 16 args, no delay:
0x02, 0x1c, 0x07, 0x12,
0x37, 0x32, 0x29, 0x2d,
0x29, 0x25, 0x2B, 0x39,
0x00, 0x01, 0x03, 0x10,
ST7735S_GMCTRN1, 16,//2:Sparkles and rainbows,16 args, no delay:
0x03, 0x1d, 0x07, 0x06,
0x2E, 0x2C, 0x29, 0x2D,
0x2E, 0x2E, 0x37, 0x3F,
0x00, 0x00, 0x02, 0x10,
ST7735S_NORON, DELAY,//3:Normal display on, no args, w/delay
10,//10 ms delay
ST7735S_DISPON, DELAY,//4:Main screen turn on, no args w/delay
100
};

static void st7735s_reset(void)
{
//gpio_request(ST7735S_PIN_RESET, "ST7735S_PIN_RESET");
//gpio_direction_output(ST7735S_PIN_RESET, 0);
gpiod_set_value(st7735s_info.reset_gpio, 0);
mdelay(5);
gpiod_set_value(st7735s_info.reset_gpio, 1);
//gpio_free(ST7735S_PIN_RESET);
}

static void st7735s_write_command(u8 cmd)
{
gpiod_set_value(st7735s_info.dc_gpio, 0);
spi_write(st7735s_info.spi, &cmd, sizeof(cmd));
}

static void st7735s_write_data(u8 *buff, size_t buff_size)
{
gpiod_set_value(st7735s_info.dc_gpio, 1);
spi_write(st7735s_info.spi, buff, buff_size);
}

static void st7735s_execute_command_list(const u8 *addr)
{
u8 numCommands, numArgs;
u16 ms;

numCommands = *addr++;
while (numCommands--) {
u8 cmd = *addr++;
st7735s_write_command(cmd);

numArgs = *addr++;
ms = numArgs & DELAY;
numArgs &= ~DELAY;
if (numArgs) {
st7735s_write_data((u8 *)addr, numArgs);
addr += numArgs;
}

if (ms) {
ms = *addr++;
if (ms == 255)
ms = 500;
mdelay(ms);
}
}
}

static void st7735s_set_address_window(u8 x0, u8 y0, u8 x1, u8 y1)
{
u8 data[] = {0x00, x0 + ST7735S_XSTART, 0x00, x1 + ST7735S_XSTART};

st7735s_write_command(ST7735S_CASET);
st7735s_write_data(data, sizeof(data));

// row address set
st7735s_write_command(ST7735S_RASET);
data[1] = y0 + ST7735S_YSTART;
data[3] = y1 + ST7735S_YSTART;
st7735s_write_data(data, sizeof(data));

// write to RAM
st7735s_write_command(ST7735S_RAMWR);
}

inline void st7735s_update_screen(void)
{
st7735s_write_data((u8 *)frame_buffer, sizeof(u16) * ST7735S_WIDTH * ST7735S_HEIGHT);
}

void st7735s_draw_pixel(u16 x, u16 y, u16 color)
{
if ((x >= ST7735S_WIDTH) || (y >= ST7735S_HEIGHT)) {
goto out;
}

frame_buffer[x + ST7735S_WIDTH * y] = color;
st7735s_update_screen();

out:
return;
}

void st7735s_fill_rectangle(u16 x, u16 y, u16 w, u16 h, u16 color)
{
u16 i;
u16 j;

if ((x >= ST7735S_WIDTH) || (y >= ST7735S_HEIGHT)) {
goto out;
}

if ((x + w - 1) > ST7735S_WIDTH) {
w = ST7735S_WIDTH - x;
}

if ((y + h - 1) > ST7735S_HEIGHT) {
h = ST7735S_HEIGHT - y;
}

for (j = 0; j < h; ++j) {
for (i = 0; i < w; ++i) {
frame_buffer[(x + ST7735S_WIDTH * y) + (i + ST7735S_WIDTH * j)] = color;
}
}

st7735s_update_screen();

out:
return;
}

void st7735s_fill_screen(u16 color)
{
st7735s_fill_rectangle(0, 0, ST7735S_WIDTH, ST7735S_HEIGHT, color);
}

////////////////////////////////////////////////////////////////////////////////

static int st7735s_probe(struct spi_device *spi)
{
int ret;
u32 spi_frequency = 500000;
struct device_node *np = spi->dev.of_node;

dev_info(&spi->dev, "%s:%d\n", __func__, __LINE__);

if (of_get_property(np, "spi-max-frequency", NULL)) {

of_property_read_u32(np, "spi-max-frequency", &spi_frequency);
}

spi->bits_per_word = 8;
spi->mode = SPI_MODE_0;
spi->max_speed_hz = 500000;
spi->max_speed_hz = spi_frequency;

dev_info(&spi->dev, "%s:%d max_speed_hz:%d\n", __func__, __LINE__, spi->max_speed_hz);

ret = spi_setup(spi);
if (ret < 0)
return ret;

st7735s_info.spi = spi;

st7735s_info.dc_gpio = gpiod_get(&spi->dev, "dc", GPIOD_OUT_LOW);
if (IS_ERR(st7735s_info.dc_gpio)) {
dev_info(&spi->dev, "%s:%d\n", __func__, __LINE__);
st7735s_info.dc_gpio = NULL;
}

st7735s_info.reset_gpio = gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(st7735s_info.reset_gpio)) {
dev_info(&spi->dev, "%s:%d\n", __func__, __LINE__);
st7735s_info.reset_gpio = NULL;
}



st7735s_reset();
st7735s_execute_command_list(init_cmds1);
st7735s_execute_command_list(init_cmds2);
st7735s_execute_command_list(init_cmds3);
pr_info("st7735s: device init completed\n");

memset(frame_buffer, 0xFFFF, sizeof(frame_buffer));

st7735s_set_address_window(0, 0, ST7735S_WIDTH - 1, ST7735S_HEIGHT - 1);

//Examples

st7735s_fill_screen(0x0000);

st7735s_fill_rectangle(20, 130, 50, 20, 0x1111);
st7735s_fill_rectangle(20, 55 + 60, 20, 60, 0x2222);
st7735s_fill_rectangle(20 + 40, 55 + 60, 20, 60, 0x3333);
st7735s_fill_rectangle(79, 80, 50, 60, 0x4444);
st7735s_fill_rectangle(0, 0, 50, 60, 0x5555);

dev_info(&spi->dev, "%s:%d\n", __func__, __LINE__);
return 0;

Expand All @@ -32,6 +328,8 @@ static int st7735s_probe(struct spi_device *spi)

static int st7735s_remove(struct spi_device *spi)
{
gpiod_put(st7735s_info.dc_gpio);
gpiod_put(st7735s_info.reset_gpio);
return 0;
}

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21 changes: 10 additions & 11 deletions st7735s/sun8i-h3-st7735s.dts
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Original file line number Diff line number Diff line change
Expand Up @@ -14,19 +14,18 @@
target-path = "/soc/spi@1c68000";
__overlay__ {
status = "okay";
/*
spidev@0 {
compatible = "spidev";
spi-max-frequency = <10000000>;
reg = <0>;
status = "okay";
};
*/

st7735s {
st7735s@0 {
compatible = "st7735s";
spi-max-frequency = <10000000>;
reg = <0>;
reg = <0>; /* CS #0 */
spi-max-frequency = <5000000>;

/* &pio, PA_BASE, PC7, GPIO_ACTIVE_HIGH*/
dc-gpios = <&pio 2 7 0>;

/* &pio, PA_BASE, PA2, GPIO_ACTIVE_HIGH*/
reset-gpios = <&pio 0 2 0>;

status = "okay";
};

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