From: zhangxuezhi zhangxuezhi1@yulong.com
For st7789v ic,when we need continuous full screen refresh, it is best to wait for the TE signal arrive to avoid screen tearing
Signed-off-by: zhangxuezhi zhangxuezhi1@yulong.com --- v12: change dev_err to dev_err_probe and add space in comments start, and delete te_mutex, change te wait logic v11: remove devm_gpio_put and change a dev_err to dev_info v10: additional notes v9: change pr_* to dev_* v8: delete a log line v7: return error value when request fail v6: add te gpio request fail deal logic v5: fix log print v4: modify some code style and change te irq set function name v3: modify author and signed-off-by name v2: add release te gpio after irq request fail --- drivers/staging/fbtft/fb_st7789v.c | 116 +++++++++++++++++++++++++++++++++++++ drivers/staging/fbtft/fbtft.h | 1 + 2 files changed, 117 insertions(+)
diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c index 3a280cc..f08e9da 100644 --- a/drivers/staging/fbtft/fb_st7789v.c +++ b/drivers/staging/fbtft/fb_st7789v.c @@ -9,7 +9,11 @@ #include <linux/delay.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/completion.h> #include <linux/module.h> +#include <linux/gpio/consumer.h> + #include <video/mipi_display.h>
#include "fbtft.h" @@ -66,6 +70,15 @@ enum st7789v_command { #define MADCTL_MX BIT(6) /* bitmask for column address order */ #define MADCTL_MY BIT(7) /* bitmask for page address order */
+#define SPI_PANEL_TE_TIMEOUT 400 /* msecs */ +static struct completion spi_panel_te; + +static irqreturn_t spi_panel_te_handler(int irq, void *data) +{ + complete(&spi_panel_te); + return IRQ_HANDLED; +} + /** * init_display() - initialize the display controller * @@ -82,6 +95,29 @@ enum st7789v_command { */ static int init_display(struct fbtft_par *par) { + int rc; + struct device *dev = par->info->device; + + par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0, GPIOD_IN); + if (IS_ERR(par->gpio.te)) + return dev_err_probe(par->info->device, PTR_ERR(par->gpio.te), + "Failed to request te gpio\n"); + + if (par->gpio.te) { + init_completion(&spi_panel_te); + rc = devm_request_irq(dev, + gpiod_to_irq(par->gpio.te), + spi_panel_te_handler, IRQF_TRIGGER_RISING, + "TE_GPIO", par); + if (IS_ERR(rc)) + return dev_err_probe(par->info->device, PTR_ERR(rc), + "TE request_irq failed.\n"); + + disable_irq_nosync(gpiod_to_irq(par->gpio.te)); + } else { + dev_info(par->info->device, "%s:%d, TE gpio not specified\n", + __func__, __LINE__); + } /* turn off sleep mode */ write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE); mdelay(120); @@ -137,6 +173,10 @@ static int init_display(struct fbtft_par *par) */ write_reg(par, PWCTRL1, 0xA4, 0xA1);
+ /* tearing effect line on */ + if (par->gpio.te) + write_reg(par, 0x35, 0x00); + write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
if (HSD20_IPS) @@ -146,6 +186,81 @@ static int init_display(struct fbtft_par *par) }
/** + * st7789v_write_vmem16_bus8() - write data to display + * + * @par: FBTFT parameter object + * @offset: offset from screen_buffer + * @len: the length of data to be written + * + * 16 bit pixel over 8-bit databus + * + * Return: 0 on success, < 0 if error occurred. + */ + +static int st7789v_write_vmem16_bus8(struct fbtft_par *par, size_t offset, size_t len) +{ + u16 *vmem16; + __be16 *txbuf16 = par->txbuf.buf; + size_t remain; + size_t to_copy; + size_t tx_array_size; + int i; + int ret = 0; + size_t startbyte_size = 0; + + fbtft_par_dbg(DEBUG_WRITE_VMEM, par, "st7789v ---%s(offset=%zu, len=%zu)\n", + __func__, offset, len); + + remain = len / 2; + vmem16 = (u16 *)(par->info->screen_buffer + offset); + + if (par->gpio.dc) + gpiod_set_value(par->gpio.dc, 1); + + if (par->gpio.te) { + enable_irq(gpiod_to_irq(par->gpio.te)); + reinit_completion(&spi_panel_te); + ret = wait_for_completion_timeout(&spi_panel_te, + msecs_to_jiffies(SPI_PANEL_TE_TIMEOUT)); + if (ret == 0) + dev_err(par->info->device, "wait panel TE time out\n"); + + disable_irq(gpiod_to_irq(par->gpio.te)); + } + /* non buffered write */ + if (!par->txbuf.buf) + return par->fbtftops.write(par, vmem16, len); + + /* buffered write */ + tx_array_size = par->txbuf.len / 2; + + if (par->startbyte) { + txbuf16 = par->txbuf.buf + 1; + tx_array_size -= 2; + *(u8 *)(par->txbuf.buf) = par->startbyte | 0x2; + startbyte_size = 1; + } + + while (remain) { + to_copy = min(tx_array_size, remain); + dev_dbg(par->info->device, " to_copy=%zu, remain=%zu\n", + to_copy, remain - to_copy); + + for (i = 0; i < to_copy; i++) + txbuf16[i] = cpu_to_be16(vmem16[i]); + + vmem16 = vmem16 + to_copy; + ret = par->fbtftops.write(par, par->txbuf.buf, + startbyte_size + to_copy * 2); + if (ret < 0) + return ret; + remain -= to_copy; + } + + return ret; +} + +/** * set_var() - apply LCD properties like rotation and BGR mode * * @par: FBTFT parameter object @@ -259,6 +374,7 @@ static int blank(struct fbtft_par *par, bool on) .gamma = HSD20_IPS_GAMMA, .fbtftops = { .init_display = init_display, + .write_vmem = st7789v_write_vmem16_bus8, .set_var = set_var, .set_gamma = set_gamma, .blank = blank, diff --git a/drivers/staging/fbtft/fbtft.h b/drivers/staging/fbtft/fbtft.h index 76f8c09..93bac05 100644 --- a/drivers/staging/fbtft/fbtft.h +++ b/drivers/staging/fbtft/fbtft.h @@ -212,6 +212,7 @@ struct fbtft_par { struct gpio_desc *wr; struct gpio_desc *latch; struct gpio_desc *cs; + struct gpio_desc *te; struct gpio_desc *db[16]; struct gpio_desc *led[16]; struct gpio_desc *aux[16];