Re: [PATCH v9] staging: fbtft: add tearing signal detect

[carlis <zhangxuezhi3@gmail.com>]

On Wed, 27 Jan 2021 14:47:04 +0100
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> Hi Carlis,
> 
> On Wed, Jan 27, 2021 at 2:03 PM Carlis <zhangxuezhi3@gmail.com> wrote:
> > From: zhangxuezhi <zhangxuezhi1@yulong.com>
> >
> > For st7789v ic,add tearing signal detect to avoid screen tearing
> >
> > Signed-off-by: zhangxuezhi <zhangxuezhi1@yulong.com>
> > ---
> > v9: change pr_* to dev_*  
> 
> Thanks for the update!
> 
> > --- 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
> > +static struct mutex te_mutex;/*mutex for tearing line*/
> > +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);  
> 
> This also prints an error in case of -EPROBE_DEFER.
> dev_err_probe()?
> 
> > +               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);  
> 
> No need to call devm_gpiod_put() here, as it's managed automatically.
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 

hi,i will fix in patch v11
regards
zhangxuezhi1