#include <linux/module.h>
#include <linux/platform_data/simplefb.h>
#include <linux/platform_device.h>
+#include <linux/clk-provider.h>
+#include <linux/of_platform.h>
static struct fb_fix_screeninfo simplefb_fix = {
.id = "simple",
.vmode = FB_VMODE_NONINTERLACED,
};
+#define PSEUDO_PALETTE_SIZE 16
+
static int simplefb_setcolreg(u_int regno, u_int red, u_int green, u_int blue,
u_int transp, struct fb_info *info)
{
u32 cb = blue >> (16 - info->var.blue.length);
u32 value;
- if (regno >= 16)
+ if (regno >= PSEUDO_PALETTE_SIZE)
return -EINVAL;
value = (cr << info->var.red.offset) |
return 0;
}
+struct simplefb_par {
+ u32 palette[PSEUDO_PALETTE_SIZE];
+#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
+ int clk_count;
+ struct clk **clks;
+#endif
+};
+
+#if defined CONFIG_OF && defined CONFIG_COMMON_CLK
+/*
+ * Clock handling code.
+ *
+ * Here we handle the clocks property of our "simple-framebuffer" dt node.
+ * This is necessary so that we can make sure that any clocks needed by
+ * the display engine that the bootloader set up for us (and for which it
+ * provided a simplefb dt node), stay up, for the life of the simplefb
+ * driver.
+ *
+ * When the driver unloads, we cleanly disable, and then release the clocks.
+ *
+ * We only complain about errors here, no action is taken as the most likely
+ * error can only happen due to a mismatch between the bootloader which set
+ * up simplefb, and the clock definitions in the device tree. Chances are
+ * that there are no adverse effects, and if there are, a clean teardown of
+ * the fb probe will not help us much either. So just complain and carry on,
+ * and hope that the user actually gets a working fb at the end of things.
+ */
+static int simplefb_clocks_init(struct simplefb_par *par,
+ struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct clk *clock;
+ int i, ret;
+
+ if (dev_get_platdata(&pdev->dev) || !np)
+ return 0;
+
+ par->clk_count = of_clk_get_parent_count(np);
+ if (par->clk_count <= 0)
+ return 0;
+
+ par->clks = kcalloc(par->clk_count, sizeof(struct clk *), GFP_KERNEL);
+ if (!par->clks)
+ return -ENOMEM;
+
+ for (i = 0; i < par->clk_count; i++) {
+ clock = of_clk_get(np, i);
+ if (IS_ERR(clock)) {
+ if (PTR_ERR(clock) == -EPROBE_DEFER) {
+ while (--i >= 0) {
+ if (par->clks[i])
+ clk_put(par->clks[i]);
+ }
+ kfree(par->clks);
+ return -EPROBE_DEFER;
+ }
+ dev_err(&pdev->dev, "%s: clock %d not found: %ld\n",
+ __func__, i, PTR_ERR(clock));
+ continue;
+ }
+ par->clks[i] = clock;
+ }
+
+ for (i = 0; i < par->clk_count; i++) {
+ if (par->clks[i]) {
+ ret = clk_prepare_enable(par->clks[i]);
+ if (ret) {
+ dev_err(&pdev->dev,
+ "%s: failed to enable clock %d: %d\n",
+ __func__, i, ret);
+ clk_put(par->clks[i]);
+ par->clks[i] = NULL;
+ }
+ }
+ }
+
+ return 0;
+}
+
+static void simplefb_clocks_destroy(struct simplefb_par *par)
+{
+ int i;
+
+ if (!par->clks)
+ return;
+
+ for (i = 0; i < par->clk_count; i++) {
+ if (par->clks[i]) {
+ clk_disable_unprepare(par->clks[i]);
+ clk_put(par->clks[i]);
+ }
+ }
+
+ kfree(par->clks);
+}
+#else
+static int simplefb_clocks_init(struct simplefb_par *par,
+ struct platform_device *pdev) { return 0; }
+static void simplefb_clocks_destroy(struct simplefb_par *par) { }
+#endif
+
static int simplefb_probe(struct platform_device *pdev)
{
int ret;
struct simplefb_params params;
struct fb_info *info;
+ struct simplefb_par *par;
struct resource *mem;
if (fb_get_options("simplefb", NULL))
return -EINVAL;
}
- info = framebuffer_alloc(sizeof(u32) * 16, &pdev->dev);
+ info = framebuffer_alloc(sizeof(struct simplefb_par), &pdev->dev);
if (!info)
return -ENOMEM;
platform_set_drvdata(pdev, info);
+ par = info->par;
+
info->fix = simplefb_fix;
info->fix.smem_start = mem->start;
info->fix.smem_len = resource_size(mem);
info->apertures = alloc_apertures(1);
if (!info->apertures) {
- framebuffer_release(info);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto error_fb_release;
}
info->apertures->ranges[0].base = info->fix.smem_start;
info->apertures->ranges[0].size = info->fix.smem_len;
info->screen_base = ioremap_wc(info->fix.smem_start,
info->fix.smem_len);
if (!info->screen_base) {
- framebuffer_release(info);
- return -ENODEV;
+ ret = -ENOMEM;
+ goto error_fb_release;
}
- info->pseudo_palette = (void *)(info + 1);
+ info->pseudo_palette = par->palette;
+
+ ret = simplefb_clocks_init(par, pdev);
+ if (ret < 0)
+ goto error_unmap;
dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n",
info->fix.smem_start, info->fix.smem_len,
ret = register_framebuffer(info);
if (ret < 0) {
dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret);
- iounmap(info->screen_base);
- framebuffer_release(info);
- return ret;
+ goto error_clocks;
}
dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node);
return 0;
+
+error_clocks:
+ simplefb_clocks_destroy(par);
+error_unmap:
+ iounmap(info->screen_base);
+error_fb_release:
+ framebuffer_release(info);
+ return ret;
}
static int simplefb_remove(struct platform_device *pdev)
{
struct fb_info *info = platform_get_drvdata(pdev);
+ struct simplefb_par *par = info->par;
unregister_framebuffer(info);
+ simplefb_clocks_destroy(par);
framebuffer_release(info);
return 0;
.probe = simplefb_probe,
.remove = simplefb_remove,
};
-module_platform_driver(simplefb_driver);
+
+static int __init simplefb_init(void)
+{
+ int ret;
+ struct device_node *np;
+
+ ret = platform_driver_register(&simplefb_driver);
+ if (ret)
+ return ret;
+
+ if (IS_ENABLED(CONFIG_OF) && of_chosen) {
+ for_each_child_of_node(of_chosen, np) {
+ if (of_device_is_compatible(np, "simple-framebuffer"))
+ of_platform_device_create(np, NULL, NULL);
+ }
+ }
+
+ return 0;
+}
+
+fs_initcall(simplefb_init);
MODULE_AUTHOR("Stephen Warren <swarren@wwwdotorg.org>");
MODULE_DESCRIPTION("Simple framebuffer driver");
projects / firefly-linux-kernel-4.4.55.git / blobdiff