Re: [PATCHv2 07/10] fbdev: ssd1307fb: Add module parameter to set refresh rate of the display
From: Maxime Ripard
Date: Thu Mar 05 2015 - 17:15:10 EST
On Sun, Mar 01, 2015 at 11:28:00PM +0100, Thomas Niederprüm wrote:
> This patch adds the module parameter "refreshrate" to set delay for the
> deferred io. The refresh rate is given in units of Hertz. The default
> refresh rate is 1 Hz.
>
> Signed-off-by: Thomas Niederprüm <niederp@xxxxxxxxxxxxxxxx>
> ---
> drivers/video/fbdev/ssd1307fb.c | 23 +++++++++++++++++------
> 1 file changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c
> index c7ed287..ea58e87 100644
> --- a/drivers/video/fbdev/ssd1307fb.c
> +++ b/drivers/video/fbdev/ssd1307fb.c
> @@ -43,6 +43,11 @@
> #define SSD1307FB_SET_COM_PINS_CONFIG 0xda
> #define SSD1307FB_SET_VCOMH 0xdb
>
> +#define REFRASHRATE 1
> +
> +static u_int refreshrate = REFRASHRATE;
> +module_param(refreshrate, uint, 0);
> +
> static u_int contrast = 128;
> module_param(contrast, uint, S_IRUGO);
>
> @@ -270,11 +275,6 @@ static void ssd1307fb_deferred_io(struct fb_info *info,
> ssd1307fb_update_display(info->par);
> }
>
> -static struct fb_deferred_io ssd1307fb_defio = {
> - .delay = HZ,
> - .deferred_io = ssd1307fb_deferred_io,
> -};
> -
> static int ssd1307fb_init(struct ssd1307fb_par *par)
> {
> int ret;
> @@ -475,6 +475,7 @@ static int ssd1307fb_probe(struct i2c_client *client,
> {
> struct fb_info *info;
> struct device_node *node = client->dev.of_node;
> + struct fb_deferred_io *ssd1307fb_defio;
> u32 vmem_size;
> struct ssd1307fb_par *par;
> u8 *vmem;
> @@ -544,10 +545,20 @@ static int ssd1307fb_probe(struct i2c_client *client,
> goto fb_alloc_error;
> }
>
> + ssd1307fb_defio = devm_kzalloc(&client->dev, sizeof(struct fb_deferred_io), GFP_KERNEL);
> + if (!ssd1307fb_defio) {
> + dev_err(&client->dev, "Couldn't allocate deferred io.\n");
> + ret = -ENOMEM;
> + goto fb_alloc_error;
> + }
> +
> + ssd1307fb_defio->delay = HZ/refreshrate;
a space around the operator.
I'm not so sure this is a good solution, since you might perfectly
want to have an SSD1305 with a refreshrate of 1Hz, and an SSD1306 with
a refreshrate of 20Hz.
Unfortunately, beside sysfs, I don't really have a better suggestion.
Thanks!
Maxime
--
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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