linux-ti33x-psp 3.2: make st7735fb DMA safe

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>
Signed-off-by: Denys Dmytriyenko <denys@ti.com>

2 files changed, 145 insertions, 1 deletions

diff --git a/recipes-kernel/linux/linux-ti33x-psp-3.2/beaglebone/0043-st7735fb-Working-WIP-changes-to-make-DMA-safe-and-ad.patch b/recipes-kernel/linux/linux-ti33x-psp-3.2/beaglebone/0043-st7735fb-Working-WIP-changes-to-make-DMA-safe-and-ad.patch
new file mode 100644
index 00000000..5e4b6b35
--- /dev/null
+++ b/recipes-kernel/linux/linux-ti33x-psp-3.2/beaglebone/0043-st7735fb-Working-WIP-changes-to-make-DMA-safe-and-ad.patch
@@ -0,0 +1,143 @@
+From 783a66842e956b2eb9d7dc379848fbf79a370bc8 Mon Sep 17 00:00:00 2001
+From: Matt Porter <mporter@ti.com>
+Date: Wed, 28 Mar 2012 23:35:44 -0400
+Subject: [PATCH] st7735fb: Working WIP changes to make DMA safe and add
+ endian fix
+
+This removes the "from the stack" allocation of 1 byte buffers
+that was a temporary thing and isn't dma safe. Now vmallocs the
+user buffer to be deferred I/O safe and kmallocs a swapped
+shadow buffer to support the byte swabbing hack to fix userspace
+limitations.
+
+The buffer allocation and endian hack code needs some serious
+cleanup as on big endian systems if would fail miserably atm.
+However, the LE path works for the moment so people can do something
+with the driver.
+
+Signed-off-by: Matt Porter <mporter@ti.com>
+---
+ drivers/video/st7735fb.c |   49 ++++++++++++++++++++++++++++++----------------
+ include/video/st7735fb.h |    2 +
+ 2 files changed, 34 insertions(+), 17 deletions(-)
+
+diff --git a/drivers/video/st7735fb.c b/drivers/video/st7735fb.c
+index 500cc88..0931ca2 100644
+--- a/drivers/video/st7735fb.c
++++ b/drivers/video/st7735fb.c
+@@ -145,11 +145,9 @@ static struct fb_var_screeninfo st7735fb_var __devinitdata = {
+ 
+ static int st7735_write(struct st7735fb_par *par, u8 data)
+ {
+-       u8 txbuf[2]; /* allocation from stack must go */
++       par->buf[0] = data;
+ 
+-       txbuf[0] = data;
+-
+-       return spi_write(par->spi, &txbuf[0], 1);
++       return spi_write(par->spi, par->buf, 1);
+ }
+ 
+ static void st7735_write_data(struct st7735fb_par *par, u8 data)
+@@ -243,16 +241,17 @@ static void st7735_reset(struct st7735fb_par *par)
+ static void st7735fb_update_display(struct st7735fb_par *par)
+ {
+        int ret = 0;
+-       u8 *vmem = par->info->screen_base;
+-
+-       /*
+-               TODO:
+-               Allow a subset of pages to be passed in
+-               (for deferred I/O).  Check pages against
+-               pan display settings to see if they
+-               should be updated.
+-       */
+-       /* For now, just write the full 40KiB on each update */
++       u16 *vmem;
++#ifdef __LITTLE_ENDIAN
++       int i;
++       u16 *vmem16 = (u16 *)par->info->screen_base;
++       vmem = par->ssbuf;
++
++       for (i=0; i<WIDTH*HEIGHT*BPP/8/2; i++)
++               vmem[i] = swab16(vmem16[i]);
++#else
++       vmem = (u16 *)par->info->screen_base;
++#endif
+ 
+        /* Set row/column data window */
+        st7735_set_addr_win(par, 0, 0, WIDTH-1, HEIGHT-1);
+@@ -261,7 +260,7 @@ static void st7735fb_update_display(struct st7735fb_par *par)
+        st7735_write_cmd(par, ST7735_RAMWR);
+ 
+        /* Blast framebuffer to ST7735 internal display RAM */
+-       ret = st7735_write_data_buf(par, vmem, WIDTH*HEIGHT*BPP/8);
++       ret = st7735_write_data_buf(par, (u8 *)vmem, WIDTH*HEIGHT*BPP/8);
+        if (ret < 0)
+                pr_err("%s: spi_write failed to update display buffer\n",
+                        par->info->fix.id);
+@@ -369,7 +368,7 @@ static struct fb_ops st7735fb_ops = {
+ };
+ 
+ static struct fb_deferred_io st7735fb_defio = {
+-       .delay          = HZ,
++       .delay          = HZ/20,
+        .deferred_io    = st7735fb_deferred_io,
+ };
+ 
+@@ -395,7 +394,11 @@ static int __devinit st7735fb_probe (struct spi_device *spi)
+                return -EINVAL;
+        }
+ 
+-       vmem = vzalloc(vmem_size);
++#ifdef __LITTLE_ENDIAN
++       vmem = (u8 *)vmalloc(vmem_size);
++#else
++       vmem = (u8 *)kmalloc(vmem_size, GFP_KERNEL);
++#endif
+        if (!vmem)
+                return retval;
+ 
+@@ -431,6 +434,14 @@ static int __devinit st7735fb_probe (struct spi_device *spi)
+        par->spi = spi;
+        par->rst = pdata->rst_gpio;
+        par->dc = pdata->dc_gpio;
++       par->buf = kmalloc(1, GFP_KERNEL);
++
++#ifdef __LITTLE_ENDIAN
++       /* Allocated swapped shadow buffer */
++       par->ssbuf = kmalloc(vmem_size, GFP_KERNEL);
++       if (!par->ssbuf)
++               return retval;
++#endif
+ 
+        retval = register_framebuffer(info);
+        if (retval < 0)
+@@ -457,7 +468,11 @@ fbreg_fail:
+        framebuffer_release(info);
+ 
+ fballoc_fail:
++#ifdef __LITTLE_ENDIAN
+        vfree(vmem);
++#else
++       kfree(vmem);
++#endif
+ 
+        return retval;
+ }
+diff --git a/include/video/st7735fb.h b/include/video/st7735fb.h
+index 250f036..e99cd05 100644
+--- a/include/video/st7735fb.h
++++ b/include/video/st7735fb.h
+@@ -36,6 +36,8 @@ struct st7735fb_par {
+        struct fb_info *info;
+        int rst;
+        int dc;
++       u16 *ssbuf;
++       u8 *buf;
+ };
+ 
+ struct st7735fb_platform_data {
+-- 
+1.7.7.6
+
diff --git a/recipes-kernel/linux/linux-ti33x-psp_3.2.bb b/recipes-kernel/linux/linux-ti33x-psp_3.2.bb
index 05772b4a..bb26c70f 100644
--- a/recipes-kernel/linux/linux-ti33x-psp_3.2.bb
+++ b/recipes-kernel/linux/linux-ti33x-psp_3.2.bb
@@ -12,7 +12,7 @@ MULTI_CONFIG_BASE_SUFFIX = ""
 
 BRANCH = "v3.2-staging"
 SRCREV = "720e07b4c1f687b61b147b31c698cb6816d72f01"
-MACHINE_KERNEL_PR_append = "i+gitr${SRCREV}"
+MACHINE_KERNEL_PR_append = "j+gitr${SRCREV}"
 
 COMPATIBLE_MACHINE = "(ti33x)"
 
@@ -967,5 +967,6 @@ PATCHES_OVER_PSP = " \
         file://beaglebone/0038-board-am335xevm.c-Beaglebone-expose-all-pwms-through.patch \
         file://beaglebone/0039-ARM-OMAP-Mux-Fixed-debugfs-mux-output-always-reporti.patch \
         file://beaglebone/0040-beaglebone-export-SPI2-as-spidev-when-no-capes-are-u.patch \
+    file://beaglebone/0043-st7735fb-Working-WIP-changes-to-make-DMA-safe-and-ad.patch \
         file://beaglebone/0001-arm-boot-compressed-default-asm-arch-to-armv7-a.patch \
 "