On Thu, Jan 28, 2021 at 2:58 PM Carlis zhangxuezhi3@gmail.com wrote:
Thanks for your contribution, my comments below.
From: zhangxuezhi zhangxuezhi1@yulong.com
You probably have to configure your Git to use the same account for author and committer.
For st7789v ic,when we need continuous full screen refresh, it is best to
'ic,when' -> 'IC, when'
wait for the TE signal arrive to avoid screen tearing
Decode TE for people who are not familiar with the abbreviation.
Missed period at the end of sentence.
...
#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>
Good, but I would rather squeeze it above to be more or less ordered, like just after delay.h inclusion.
#include <video/mipi_display.h>
...
+#define SPI_PANEL_TE_TIMEOUT 400 /* msecs */
Useless comment. Instead use _MS suffix in the name of constant. Besides that please add a comment explaining why this value has been chosen.
...
+static struct completion spi_panel_te;
As Greg said.
...
static int init_display(struct fbtft_par *par) {
int rc;struct device *dev = par->info->device;
Keep reversed xmas tree order:
struct device *dev = par->info->device; int rc;
...
par->gpio.te = devm_gpiod_get_index_optional(dev, "te", 0, GPIOD_IN);
No need to have it requested for all time since you use it as an IRQ later on. The IRQ chip will call the GPIO library framework to lock a pin as IRQ anyway.
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) {
Instead you should probably do the following:
int irq;
irq = gpiod_to_irq(...); if (irq > 0)
init_completion(&spi_panel_te);rc = devm_request_irq(dev,
gpiod_to_irq(par->gpio.te),
...and here simply use irq.
spi_panel_te_handler, IRQF_TRIGGER_RISING,"TE_GPIO", par);
if (IS_ERR(rc))
This is wrong. rc is integer no IS_ERR() is required. Ditto for PTR_ERR(). Have you even looked for these macros implementations?
return dev_err_probe(par->info->device, PTR_ERR(rc),
Use your temporary variable and move...
"TE request_irq failed.\n");
...this on the previous line.
disable_irq_nosync(gpiod_to_irq(par->gpio.te));
Why do you call gpio_to_irq() twice?
} else {dev_info(par->info->device, "%s:%d, TE gpio not specified\n",__func__, __LINE__);
Remove this noise (besides the fact that we don't use __file__ and __LINE__ in messages like this.
}
Taking all together you probably need to create a helper and use it inside init_display(), like
static int init_tearing_effect_line(struct fbtft_par *par) { struct device *dev = par->info->device; struct gpio_desc *te; int irq, rc;
te = gpiod_get_optional(dev, "te", GPIOD_IN); if (IS_ERR(te)) return dev_err_probe(dev, PTR_ERR(te), "Failed to request te GPIO\n");
irq = gpiod_to_irq(te); // this value you have to save in the driver's (per device) data structure.
/* GPIO is locked as an IRQ, we may drop the reference */ gpiod_put(te);
init_completion(&spi_panel_te); // should be in the (per device) data structure rc = devm_request_irq(dev, irq, spi_panel_te_handler, IRQF_TRIGGER_RISING, "TE_GPIO", par); if (rc) return dev_err_probe(dev, rc, "TE IRQ request failed.\n"); disable_irq_nosync(irq); return irq; }
Note, when you define proper fields for IRQ line and completion in the data structure the above can be amended accordingly.
...
/* tearing effect line on */if (par->gpio.te)write_reg(par, 0x35, 0x00);
0x35 is defined. use it and drop useless comments.
...
/**
- st7789v_write_vmem16_bus8() - write data to display
Redundant blank line.
- @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.
", or a negative error code otherwise"
- */
Redundant blank line
+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;
Reversed xmas tree order.
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)
Useless duplicate check.
gpiod_set_value(par->gpio.dc, 1);
if (par->gpio.te) {enable_irq(gpiod_to_irq(par->gpio.te));
Here you should use the IRQ line rather than the GPIO descriptor. See above.
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));}
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);
Like in previous functions create a temporary variable to keep a pointer to struct device and use it here and everywhere else. It might save you LOCs and make code easier to read and understand.
for (i = 0; i < to_copy; i++)txbuf16[i] = cpu_to_be16(vmem16[i]);
If both of them are 16-bit wide, consider moving this to a helper which somebody can move to byteorder/generic.h in the future.
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;+}