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 --- 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 | 132 ++++++++++++++++++++++++++++++++++++- drivers/staging/fbtft/fbtft.h | 1 + 2 files changed, 132 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c index 3a280cc..cba08a8 100644 --- a/drivers/staging/fbtft/fb_st7789v.c +++ b/drivers/staging/fbtft/fb_st7789v.c @@ -9,9 +9,12 @@ #include <linux/delay.h> #include <linux/init.h> #include <linux/kernel.h> +#include <linux/mutex.h> +#include <linux/interrupt.h> +#include <linux/completion.h> #include <linux/module.h> #include <video/mipi_display.h> - +#include <linux/gpio/consumer.h> #include "fbtft.h"
#define DRVNAME "fb_st7789v" @@ -66,6 +69,32 @@ 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 mutex te_mutex;/* mutex for set te gpio irq status */ +static struct completion spi_panel_te; + +static irqreturn_t spi_panel_te_handler(int irq, void *data) +{ + complete(&spi_panel_te); + return IRQ_HANDLED; +} + +static void set_spi_panel_te_irq_status(struct fbtft_par *par, bool enable) +{ + static int te_irq_count; + + mutex_lock(&te_mutex); + + if (enable) { + if (++te_irq_count == 1) + enable_irq(gpiod_to_irq(par->gpio.te)); + } else { + if (--te_irq_count == 0) + disable_irq(gpiod_to_irq(par->gpio.te)); + } + mutex_unlock(&te_mutex); +} + /** * init_display() - initialize the display controller * @@ -82,6 +111,33 @@ 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)) { + rc = PTR_ERR(par->gpio.te); + dev_err(par->info->device, "Failed to request te gpio: %d\n", rc); + return rc; + } + if (par->gpio.te) { + init_completion(&spi_panel_te); + mutex_init(&te_mutex); + rc = devm_request_irq(dev, + gpiod_to_irq(par->gpio.te), + spi_panel_te_handler, IRQF_TRIGGER_RISING, + "TE_GPIO", par); + if (rc) { + dev_err(par->info->device, "TE request_irq failed.\n"); + devm_gpiod_put(dev, par->gpio.te); + return rc; + } + + 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 +193,9 @@ 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) @@ -145,6 +204,76 @@ static int init_display(struct fbtft_par *par) return 0; }
+/***************************************************************************** + * + * int (*write_vmem)(struct fbtft_par *par); + * + *****************************************************************************/ + +/* 16 bit pixel over 8-bit databus */ +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); + + /* 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; + if (par->gpio.te) { + set_spi_panel_te_irq_status(par, true); + 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"); + } + ret = par->fbtftops.write(par, par->txbuf.buf, + startbyte_size + to_copy * 2); + if (par->gpio.te) + set_spi_panel_te_irq_status(par, false); + if (ret < 0) + return ret; + remain -= to_copy; + } + + return ret; +} + /** * set_var() - apply LCD properties like rotation and BGR mode * @@ -259,6 +388,7 @@ 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];