video: mxsfb: fix broken videomode selection

Currently the driver re-implements the code found in of_get_videomode()
except for the fact that the latter honors the 'native-mode' property
to select a spcific video timing from the list of possible timings.
The driver builds up a list of all video timings, but uses only the
last mode from the list anyway. While building the list it incorrectly
OR's the 'pixelclk-active' and 'de-active' flags of all modes into
single flags, possibly leading to a wrong pixelclock or data-enable
polarity setting.

Fix this by using the of_get_videomode() directly with the
OF_USE_NATIVE_MODE flag.

Since all current dts files only have one entry in their
display-timings node, this bug was not apparent and the fix does not
change the driver's behaviour for the current users.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

diff --git a/drivers/video/mxsfb.c b/drivers/video/mxsfb.c
index d11c35ce2b00b6bcbde964b4f3ad36554060ee8f..accf48a2cce43e16d8ebeea80807df2b32c9cc76 100644 (file)
--- a/drivers/video/mxsfb.c
+++ b/drivers/video/mxsfb.c
@@ -49,6 +49,7 @@
 #include <linux/fb.h>
 #include <linux/regulator/consumer.h>
 #include <video/of_display_timing.h>
+#include <video/of_videomode.h>
 #include <video/videomode.h>
 
 #define REG_SET        4
@@ -589,7 +590,8 @@ static struct fb_ops mxsfb_ops = {
        .fb_imageblit = cfb_imageblit,
 };
 
-static int mxsfb_restore_mode(struct mxsfb_info *host)
+static int mxsfb_restore_mode(struct mxsfb_info *host,
+                       struct fb_videomode *vmode)
 {
        struct fb_info *fb_info = &host->fb_info;
        unsigned line_count;
@@ -597,7 +599,6 @@ static int mxsfb_restore_mode(struct mxsfb_info *host)
        unsigned long pa, fbsize;
        int bits_per_pixel, ofs;
        u32 transfer_count, vdctrl0, vdctrl2, vdctrl3, vdctrl4, ctrl;
-       struct fb_videomode vmode;
 
        /* Only restore the mode when the controller is running */
        ctrl = readl(host->base + LCDC_CTRL);
@@ -611,8 +612,8 @@ static int mxsfb_restore_mode(struct mxsfb_info *host)
 
        transfer_count = readl(host->base + host->devdata->transfer_count);
 
-       vmode.xres = TRANSFER_COUNT_GET_HCOUNT(transfer_count);
-       vmode.yres = TRANSFER_COUNT_GET_VCOUNT(transfer_count);
+       vmode->xres = TRANSFER_COUNT_GET_HCOUNT(transfer_count);
+       vmode->yres = TRANSFER_COUNT_GET_VCOUNT(transfer_count);
 
        switch (CTRL_GET_WORD_LENGTH(ctrl)) {
        case 0:
@@ -628,40 +629,39 @@ static int mxsfb_restore_mode(struct mxsfb_info *host)
 
        fb_info->var.bits_per_pixel = bits_per_pixel;
 
-       vmode.pixclock = KHZ2PICOS(clk_get_rate(host->clk) / 1000U);
-       vmode.hsync_len = get_hsync_pulse_width(host, vdctrl2);
-       vmode.left_margin = GET_HOR_WAIT_CNT(vdctrl3) - vmode.hsync_len;
-       vmode.right_margin = VDCTRL2_GET_HSYNC_PERIOD(vdctrl2) - vmode.hsync_len -
-               vmode.left_margin - vmode.xres;
-       vmode.vsync_len = VDCTRL0_GET_VSYNC_PULSE_WIDTH(vdctrl0);
+       vmode->pixclock = KHZ2PICOS(clk_get_rate(host->clk) / 1000U);
+       vmode->hsync_len = get_hsync_pulse_width(host, vdctrl2);
+       vmode->left_margin = GET_HOR_WAIT_CNT(vdctrl3) - vmode->hsync_len;
+       vmode->right_margin = VDCTRL2_GET_HSYNC_PERIOD(vdctrl2) -
+               vmode->hsync_len - vmode->left_margin - vmode->xres;
+       vmode->vsync_len = VDCTRL0_GET_VSYNC_PULSE_WIDTH(vdctrl0);
        period = readl(host->base + LCDC_VDCTRL1);
-       vmode.upper_margin = GET_VERT_WAIT_CNT(vdctrl3) - vmode.vsync_len;
-       vmode.lower_margin = period - vmode.vsync_len - vmode.upper_margin - vmode.yres;
+       vmode->upper_margin = GET_VERT_WAIT_CNT(vdctrl3) - vmode->vsync_len;
+       vmode->lower_margin = period - vmode->vsync_len -
+               vmode->upper_margin - vmode->yres;
 
-       vmode.vmode = FB_VMODE_NONINTERLACED;
+       vmode->vmode = FB_VMODE_NONINTERLACED;
 
-       vmode.sync = 0;
+       vmode->sync = 0;
        if (vdctrl0 & VDCTRL0_HSYNC_ACT_HIGH)
-               vmode.sync |= FB_SYNC_HOR_HIGH_ACT;
+               vmode->sync |= FB_SYNC_HOR_HIGH_ACT;
        if (vdctrl0 & VDCTRL0_VSYNC_ACT_HIGH)
-               vmode.sync |= FB_SYNC_VERT_HIGH_ACT;
+               vmode->sync |= FB_SYNC_VERT_HIGH_ACT;
 
        pr_debug("Reconstructed video mode:\n");
        pr_debug("%dx%d, hsync: %u left: %u, right: %u, vsync: %u, upper: %u, lower: %u\n",
-                       vmode.xres, vmode.yres,
-                       vmode.hsync_len, vmode.left_margin, vmode.right_margin,
-                       vmode.vsync_len, vmode.upper_margin, vmode.lower_margin);
-       pr_debug("pixclk: %ldkHz\n", PICOS2KHZ(vmode.pixclock));
-
-       fb_add_videomode(&vmode, &fb_info->modelist);
+               vmode->xres, vmode->yres, vmode->hsync_len, vmode->left_margin,
+               vmode->right_margin, vmode->vsync_len, vmode->upper_margin,
+               vmode->lower_margin);
+       pr_debug("pixclk: %ldkHz\n", PICOS2KHZ(vmode->pixclock));
 
        host->ld_intf_width = CTRL_GET_BUS_WIDTH(ctrl);
        host->dotclk_delay = VDCTRL4_GET_DOTCLK_DLY(vdctrl4);
 
-       fb_info->fix.line_length = vmode.xres * (bits_per_pixel >> 3);
+       fb_info->fix.line_length = vmode->xres * (bits_per_pixel >> 3);
 
        pa = readl(host->base + host->devdata->cur_buf);
-       fbsize = fb_info->fix.line_length * vmode.yres;
+       fbsize = fb_info->fix.line_length * vmode->yres;
        if (pa < fb_info->fix.smem_start)
                return -EINVAL;
        if (pa + fbsize > fb_info->fix.smem_start + fb_info->fix.smem_len)
@@ -681,18 +681,17 @@ static int mxsfb_restore_mode(struct mxsfb_info *host)
        return 0;
 }
 
-static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host)
+static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host,
+                               struct fb_videomode *vmode)
 {
        struct fb_info *fb_info = &host->fb_info;
        struct fb_var_screeninfo *var = &fb_info->var;
        struct device *dev = &host->pdev->dev;
        struct device_node *np = host->pdev->dev.of_node;
        struct device_node *display_np;
-       struct device_node *timings_np;
-       struct display_timings *timings;
+       struct videomode vm;
        u32 width;
-       int i;
-       int ret = 0;
+       int ret;
 
        display_np = of_parse_phandle(np, "display", 0);
        if (!display_np) {
@@ -732,54 +731,35 @@ static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host)
                goto put_display_node;
        }
 
-       timings = of_get_display_timings(display_np);
-       if (!timings) {
-               dev_err(dev, "failed to get display timings\n");
-               ret = -ENOENT;
+       ret = of_get_videomode(display_np, &vm, OF_USE_NATIVE_MODE);
+       if (ret) {
+               dev_err(dev, "failed to get videomode from DT\n");
                goto put_display_node;
        }
 
-       timings_np = of_find_node_by_name(display_np,
-                                         "display-timings");
-       if (!timings_np) {
-               dev_err(dev, "failed to find display-timings node\n");
-               ret = -ENOENT;
+       ret = fb_videomode_from_videomode(&vm, vmode);
+       if (ret < 0)
                goto put_display_node;
-       }
 
-       for (i = 0; i < of_get_child_count(timings_np); i++) {
-               struct videomode vm;
-               struct fb_videomode fb_vm;
-
-               ret = videomode_from_timings(timings, &vm, i);
-               if (ret < 0)
-                       goto put_timings_node;
-               ret = fb_videomode_from_videomode(&vm, &fb_vm);
-               if (ret < 0)
-                       goto put_timings_node;
-
-               if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
-                       host->sync |= MXSFB_SYNC_DATA_ENABLE_HIGH_ACT;
-               if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
-                       host->sync |= MXSFB_SYNC_DOTCLK_FALLING_ACT;
-               fb_add_videomode(&fb_vm, &fb_info->modelist);
-       }
+       if (vm.flags & DISPLAY_FLAGS_DE_HIGH)
+               host->sync |= MXSFB_SYNC_DATA_ENABLE_HIGH_ACT;
+       if (vm.flags & DISPLAY_FLAGS_PIXDATA_NEGEDGE)
+               host->sync |= MXSFB_SYNC_DOTCLK_FALLING_ACT;
 
-put_timings_node:
-       of_node_put(timings_np);
 put_display_node:
        of_node_put(display_np);
        return ret;
 }
 
-static int mxsfb_init_fbinfo(struct mxsfb_info *host)
+static int mxsfb_init_fbinfo(struct mxsfb_info *host,
+                       struct fb_videomode *vmode)
 {
+       int ret;
        struct fb_info *fb_info = &host->fb_info;
        struct fb_var_screeninfo *var = &fb_info->var;
        dma_addr_t fb_phys;
        void *fb_virt;
        unsigned fb_size;
-       int ret;
 
        fb_info->fbops = &mxsfb_ops;
        fb_info->flags = FBINFO_FLAG_DEFAULT | FBINFO_READS_FAST;
@@ -789,7 +769,7 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host)
        fb_info->fix.visual = FB_VISUAL_TRUECOLOR,
        fb_info->fix.accel = FB_ACCEL_NONE;
 
-       ret = mxsfb_init_fbinfo_dt(host);
+       ret = mxsfb_init_fbinfo_dt(host, vmode);
        if (ret)
                return ret;
 
@@ -810,7 +790,7 @@ static int mxsfb_init_fbinfo(struct mxsfb_info *host)
        fb_info->screen_base = fb_virt;
        fb_info->screen_size = fb_info->fix.smem_len = fb_size;
 
-       if (mxsfb_restore_mode(host))
+       if (mxsfb_restore_mode(host, vmode))
                memset(fb_virt, 0, fb_size);
 
        return 0;
@@ -850,7 +830,7 @@ static int mxsfb_probe(struct platform_device *pdev)
        struct resource *res;
        struct mxsfb_info *host;
        struct fb_info *fb_info;
-       struct fb_modelist *modelist;
+       struct fb_videomode *mode;
        int ret;
 
        if (of_id)
@@ -862,6 +842,11 @@ static int mxsfb_probe(struct platform_device *pdev)
                return -ENOMEM;
        }
 
+       mode = devm_kzalloc(&pdev->dev, sizeof(struct fb_videomode),
+                       GFP_KERNEL);
+       if (mode == NULL)
+               return -ENOMEM;
+
        host = to_imxfb_host(fb_info);
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -893,15 +878,11 @@ static int mxsfb_probe(struct platform_device *pdev)
                goto fb_release;
        }
 
-       INIT_LIST_HEAD(&fb_info->modelist);
-
-       ret = mxsfb_init_fbinfo(host);
+       ret = mxsfb_init_fbinfo(host, mode);
        if (ret != 0)
                goto fb_release;
 
-       modelist = list_first_entry(&fb_info->modelist,
-                       struct fb_modelist, list);
-       fb_videomode_to_var(&fb_info->var, &modelist->mode);
+       fb_videomode_to_var(&fb_info->var, mode);
 
        /* init the color fields */
        mxsfb_check_var(&fb_info->var, fb_info);
@@ -927,7 +908,6 @@ static int mxsfb_probe(struct platform_device *pdev)
 fb_destroy:
        if (host->enabled)
                clk_disable_unprepare(host->clk);
-       fb_destroy_modelist(&fb_info->modelist);
 fb_release:
        framebuffer_release(fb_info);