From: zhangxuezhi <zhangxuez...@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 <zhangxuez...@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];
--
1.9.1
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