[PATCHv6 07/10] fbdev: ssd1307fb: Add a module parameter to set the refresh rate

From: Thomas NiederprÃm
Date: Tue Mar 31 2015 - 14:25:00 EST


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. The refresh rate set through the newly introduced
parameter applies to all instances of the driver and for now it is not
possible to change it individually.

Signed-off-by: Thomas NiederprÃm <niederp@xxxxxxxxxxxxxxxx>
Acked-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
---
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 f685d24..85eeda0 100644
--- a/drivers/video/fbdev/ssd1307fb.c
+++ b/drivers/video/fbdev/ssd1307fb.c
@@ -38,6 +38,11 @@
#define SSD1307FB_SET_COM_PINS_CONFIG 0xda
#define SSD1307FB_SET_VCOMH 0xdb

+#define REFRESHRATE 1
+
+static u_int refreshrate = REFRESHRATE;
+module_param(refreshrate, uint, 0);
+
struct ssd1307fb_par;

struct ssd1307fb_deviceinfo {
@@ -263,11 +268,6 @@ 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;
@@ -466,6 +466,7 @@ 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;
@@ -536,10 +537,20 @@ 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;
+ ssd1307fb_defio->deferred_io = ssd1307fb_deferred_io;
+
info->fbops = &ssd1307fb_ops;
info->fix = ssd1307fb_fix;
info->fix.line_length = par->width / 8;
- info->fbdefio = &ssd1307fb_defio;
+ info->fbdefio = ssd1307fb_defio;

info->var = ssd1307fb_var;
info->var.xres = par->width;
--
2.3.0

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