From 7b4b3733fd68d986c3f790e47aa6116d229e949e Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 27 Jul 2021 15:47:26 +0200 Subject: video: fbdev: ssd1307fb: Propagate errors via ssd1307fb_update_display() Make ssd1307fb_update_display() return an error code, so callers that can handle failures can propagate it. Signed-off-by: Geert Uytterhoeven Acked-by: Sam Ravnborg Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20210727134730.3765898-2-geert@linux-m68k.org --- drivers/video/fbdev/ssd1307fb.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) (limited to 'drivers/video/fbdev/ssd1307fb.c') diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index eda448b7a0c9..e6b6263e3bef 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -152,17 +152,17 @@ static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd) return ret; } -static void ssd1307fb_update_display(struct ssd1307fb_par *par) +static int ssd1307fb_update_display(struct ssd1307fb_par *par) { struct ssd1307fb_array *array; u8 *vmem = par->info->screen_buffer; unsigned int line_length = par->info->fix.line_length; unsigned int pages = DIV_ROUND_UP(par->height, 8); - int i, j, k; + int ret, i, j, k; array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA); if (!array) - return; + return -ENOMEM; /* * The screen is divided in pages, each having a height of 8 @@ -210,8 +210,9 @@ static void ssd1307fb_update_display(struct ssd1307fb_par *par) } } - ssd1307fb_write_array(par->client, array, par->width * pages); + ret = ssd1307fb_write_array(par->client, array, par->width * pages); kfree(array); + return ret; } @@ -222,6 +223,7 @@ static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf, unsigned long total_size; unsigned long p = *ppos; void *dst; + int ret; total_size = info->fix.smem_len; @@ -239,7 +241,9 @@ static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf, if (copy_from_user(dst, buf, count)) return -EFAULT; - ssd1307fb_update_display(par); + ret = ssd1307fb_update_display(par); + if (ret < 0) + return ret; *ppos += count; @@ -483,7 +487,9 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) return ret; /* Clear the screen */ - ssd1307fb_update_display(par); + ret = ssd1307fb_update_display(par); + if (ret < 0) + return ret; /* Turn on the display */ ret = ssd1307fb_write_cmd(par->client, SSD1307FB_DISPLAY_ON); -- cgit v1.2.3 From ef9d793825b56ec4289d2b848c9318352fa2cd13 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 27 Jul 2021 15:47:27 +0200 Subject: video: fbdev: ssd1307fb: Simplify ssd1307fb_update_display() Simplify the nested loops to handle conversion from linear frame buffer to ssd1307 page layout: 1. Move last page handling one level up, as the value of "m" is the same inside a page, 2. array->data[] is filled linearly, so there is no need to recalculate array_idx over and over again; a simple increment is sufficient. Signed-off-by: Geert Uytterhoeven Acked-by: Sam Ravnborg Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20210727134730.3765898-3-geert@linux-m68k.org --- drivers/video/fbdev/ssd1307fb.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) (limited to 'drivers/video/fbdev/ssd1307fb.c') diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index e6b6263e3bef..6d7bd025bca1 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -158,6 +158,7 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) u8 *vmem = par->info->screen_buffer; unsigned int line_length = par->info->fix.line_length; unsigned int pages = DIV_ROUND_UP(par->height, 8); + u32 array_idx = 0; int ret, i, j, k; array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA); @@ -194,19 +195,21 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) */ for (i = 0; i < pages; i++) { + int m = 8; + + /* Last page may be partial */ + if (i + 1 == pages && par->height % 8) + m = par->height % 8; for (j = 0; j < par->width; j++) { - int m = 8; - u32 array_idx = i * par->width + j; - array->data[array_idx] = 0; - /* Last page may be partial */ - if (i + 1 == pages && par->height % 8) - m = par->height % 8; + u8 data = 0; + for (k = 0; k < m; k++) { u8 byte = vmem[(8 * i + k) * line_length + j / 8]; u8 bit = (byte >> (j % 8)) & 1; - array->data[array_idx] |= bit << k; + data |= bit << k; } + array->data[array_idx++] = data; } } -- cgit v1.2.3 From 8a15af3b86f497109dc3a6646eb029d1f934684d Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 27 Jul 2021 15:47:28 +0200 Subject: video: fbdev: ssd1307fb: Extract ssd1307fb_set_{col,page}_range() Extract the code to set the column and page ranges into two helper functions. Signed-off-by: Geert Uytterhoeven Acked-by: Sam Ravnborg Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20210727134730.3765898-4-geert@linux-m68k.org --- drivers/video/fbdev/ssd1307fb.c | 57 ++++++++++++++++++++++++++--------------- 1 file changed, 37 insertions(+), 20 deletions(-) (limited to 'drivers/video/fbdev/ssd1307fb.c') diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index 6d7bd025bca1..86eb9c99a783 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -152,6 +152,40 @@ static inline int ssd1307fb_write_cmd(struct i2c_client *client, u8 cmd) return ret; } +static int ssd1307fb_set_col_range(struct ssd1307fb_par *par, u8 col_start, + u8 cols) +{ + u8 col_end = col_start + cols - 1; + int ret; + + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE); + if (ret < 0) + return ret; + + ret = ssd1307fb_write_cmd(par->client, col_start); + if (ret < 0) + return ret; + + return ssd1307fb_write_cmd(par->client, col_end); +} + +static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start, + u8 pages) +{ + u8 page_end = page_start + pages - 1; + int ret; + + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE); + if (ret < 0) + return ret; + + ret = ssd1307fb_write_cmd(par->client, page_start); + if (ret < 0) + return ret; + + return ssd1307fb_write_cmd(par->client, page_end); +} + static int ssd1307fb_update_display(struct ssd1307fb_par *par) { struct ssd1307fb_array *array; @@ -462,30 +496,13 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) return ret; /* Set column range */ - ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE); - if (ret < 0) - return ret; - - ret = ssd1307fb_write_cmd(par->client, par->col_offset); - if (ret < 0) - return ret; - - ret = ssd1307fb_write_cmd(par->client, par->col_offset + par->width - 1); + ret = ssd1307fb_set_col_range(par, par->col_offset, par->width); if (ret < 0) return ret; /* Set page range */ - ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE); - if (ret < 0) - return ret; - - ret = ssd1307fb_write_cmd(par->client, par->page_offset); - if (ret < 0) - return ret; - - ret = ssd1307fb_write_cmd(par->client, - par->page_offset + - DIV_ROUND_UP(par->height, 8) - 1); + ret = ssd1307fb_set_page_range(par, par->page_offset, + DIV_ROUND_UP(par->height, 8)); if (ret < 0) return ret; -- cgit v1.2.3 From 251e48a1db758ad7151e2dce146e63d9f4baf94b Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 27 Jul 2021 15:47:29 +0200 Subject: video: fbdev: ssd1307fb: Optimize screen updates Currently, each screen update triggers an I2C transfer of all screen data, up to 1 KiB of data for a 128x64 display, which takes at least 20 ms in Fast mode. Reduce the amount of transferred data by only updating the rectangle that changed. Remove the calls to ssd1307fb_set_col_range() and ssd1307fb_set_page_range() during initialization, as ssd1307fb_update_rect() now takes care of that. Note that for now the optimized operation is only used for fillrect, copyarea, and imageblit, which are used by fbcon. Signed-off-by: Geert Uytterhoeven Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20210727134730.3765898-5-geert@linux-m68k.org --- drivers/video/fbdev/ssd1307fb.c | 50 ++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 21 deletions(-) (limited to 'drivers/video/fbdev/ssd1307fb.c') diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index 86eb9c99a783..9aed5ee0094f 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -186,16 +186,18 @@ static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start, return ssd1307fb_write_cmd(par->client, page_end); } -static int ssd1307fb_update_display(struct ssd1307fb_par *par) +static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x, + unsigned int y, unsigned int width, + unsigned int height) { struct ssd1307fb_array *array; u8 *vmem = par->info->screen_buffer; unsigned int line_length = par->info->fix.line_length; - unsigned int pages = DIV_ROUND_UP(par->height, 8); + unsigned int pages = DIV_ROUND_UP(y % 8 + height, 8); u32 array_idx = 0; int ret, i, j, k; - array = ssd1307fb_alloc_array(par->width * pages, SSD1307FB_DATA); + array = ssd1307fb_alloc_array(width * pages, SSD1307FB_DATA); if (!array) return -ENOMEM; @@ -228,13 +230,21 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) * (5) A4 B4 C4 D4 E4 F4 G4 H4 */ - for (i = 0; i < pages; i++) { + ret = ssd1307fb_set_col_range(par, par->col_offset + x, width); + if (ret < 0) + goto out_free; + + ret = ssd1307fb_set_page_range(par, par->page_offset + y / 8, pages); + if (ret < 0) + goto out_free; + + for (i = y / 8; i < y / 8 + pages; i++) { int m = 8; /* Last page may be partial */ - if (i + 1 == pages && par->height % 8) + if (8 * (i + 1) > par->height) m = par->height % 8; - for (j = 0; j < par->width; j++) { + for (j = x; j < x + width; j++) { u8 data = 0; for (k = 0; k < m; k++) { @@ -247,11 +257,17 @@ static int ssd1307fb_update_display(struct ssd1307fb_par *par) } } - ret = ssd1307fb_write_array(par->client, array, par->width * pages); + ret = ssd1307fb_write_array(par->client, array, width * pages); + +out_free: kfree(array); return ret; } +static int ssd1307fb_update_display(struct ssd1307fb_par *par) +{ + return ssd1307fb_update_rect(par, 0, 0, par->width, par->height); +} static ssize_t ssd1307fb_write(struct fb_info *info, const char __user *buf, size_t count, loff_t *ppos) @@ -301,21 +317,24 @@ static void ssd1307fb_fillrect(struct fb_info *info, const struct fb_fillrect *r { struct ssd1307fb_par *par = info->par; sys_fillrect(info, rect); - ssd1307fb_update_display(par); + ssd1307fb_update_rect(par, rect->dx, rect->dy, rect->width, + rect->height); } static void ssd1307fb_copyarea(struct fb_info *info, const struct fb_copyarea *area) { struct ssd1307fb_par *par = info->par; sys_copyarea(info, area); - ssd1307fb_update_display(par); + ssd1307fb_update_rect(par, area->dx, area->dy, area->width, + area->height); } static void ssd1307fb_imageblit(struct fb_info *info, const struct fb_image *image) { struct ssd1307fb_par *par = info->par; sys_imageblit(info, image); - ssd1307fb_update_display(par); + ssd1307fb_update_rect(par, image->dx, image->dy, image->width, + image->height); } static const struct fb_ops ssd1307fb_ops = { @@ -495,17 +514,6 @@ static int ssd1307fb_init(struct ssd1307fb_par *par) if (ret < 0) return ret; - /* Set column range */ - ret = ssd1307fb_set_col_range(par, par->col_offset, par->width); - if (ret < 0) - return ret; - - /* Set page range */ - ret = ssd1307fb_set_page_range(par, par->page_offset, - DIV_ROUND_UP(par->height, 8)); - if (ret < 0) - return ret; - /* Clear the screen */ ret = ssd1307fb_update_display(par); if (ret < 0) -- cgit v1.2.3 From 833d14a4bf83b9be89e407b8d99b462172fe0a40 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 27 Jul 2021 15:47:30 +0200 Subject: video: fbdev: ssd1307fb: Cache address ranges Cache the column and page ranges, to avoid doing unneeded I2C transfers when the values haven't changed. Signed-off-by: Geert Uytterhoeven Acked-by: Sam Ravnborg Signed-off-by: Sam Ravnborg Link: https://patchwork.freedesktop.org/patch/msgid/20210727134730.3765898-6-geert@linux-m68k.org --- drivers/video/fbdev/ssd1307fb.c | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'drivers/video/fbdev/ssd1307fb.c') diff --git a/drivers/video/fbdev/ssd1307fb.c b/drivers/video/fbdev/ssd1307fb.c index 9aed5ee0094f..1e2f71c2f8a8 100644 --- a/drivers/video/fbdev/ssd1307fb.c +++ b/drivers/video/fbdev/ssd1307fb.c @@ -82,6 +82,11 @@ struct ssd1307fb_par { struct regulator *vbat_reg; u32 vcomh; u32 width; + /* Cached address ranges */ + u8 col_start; + u8 col_end; + u8 page_start; + u8 page_end; }; struct ssd1307fb_array { @@ -158,6 +163,9 @@ static int ssd1307fb_set_col_range(struct ssd1307fb_par *par, u8 col_start, u8 col_end = col_start + cols - 1; int ret; + if (col_start == par->col_start && col_end == par->col_end) + return 0; + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_COL_RANGE); if (ret < 0) return ret; @@ -166,7 +174,13 @@ static int ssd1307fb_set_col_range(struct ssd1307fb_par *par, u8 col_start, if (ret < 0) return ret; - return ssd1307fb_write_cmd(par->client, col_end); + ret = ssd1307fb_write_cmd(par->client, col_end); + if (ret < 0) + return ret; + + par->col_start = col_start; + par->col_end = col_end; + return 0; } static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start, @@ -175,6 +189,9 @@ static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start, u8 page_end = page_start + pages - 1; int ret; + if (page_start == par->page_start && page_end == par->page_end) + return 0; + ret = ssd1307fb_write_cmd(par->client, SSD1307FB_SET_PAGE_RANGE); if (ret < 0) return ret; @@ -183,7 +200,13 @@ static int ssd1307fb_set_page_range(struct ssd1307fb_par *par, u8 page_start, if (ret < 0) return ret; - return ssd1307fb_write_cmd(par->client, page_end); + ret = ssd1307fb_write_cmd(par->client, page_end); + if (ret < 0) + return ret; + + par->page_start = page_start; + par->page_end = page_end; + return 0; } static int ssd1307fb_update_rect(struct ssd1307fb_par *par, unsigned int x, -- cgit v1.2.3