From 03dd4cb26d967f9588437b0fc9cc0e8353322bb7 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Fri, 25 Mar 2016 03:53:42 -0300 Subject: Linux-libre 4.5-gnu --- drivers/video/fbdev/simplefb.c | 120 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 119 insertions(+), 1 deletion(-) (limited to 'drivers/video/fbdev/simplefb.c') diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c index 52c5c7e63..48ccf6db6 100644 --- a/drivers/video/fbdev/simplefb.c +++ b/drivers/video/fbdev/simplefb.c @@ -28,7 +28,10 @@ #include #include #include +#include #include +#include +#include static struct fb_fix_screeninfo simplefb_fix = { .id = "simple", @@ -174,6 +177,10 @@ struct simplefb_par { int clk_count; struct clk **clks; #endif +#if defined CONFIG_OF && defined CONFIG_REGULATOR + u32 regulator_count; + struct regulator **regulators; +#endif }; #if defined CONFIG_OF && defined CONFIG_COMMON_CLK @@ -269,6 +276,110 @@ static int simplefb_clocks_init(struct simplefb_par *par, static void simplefb_clocks_destroy(struct simplefb_par *par) { } #endif +#if defined CONFIG_OF && defined CONFIG_REGULATOR + +#define SUPPLY_SUFFIX "-supply" + +/* + * Regulator handling code. + * + * Here we handle the num-supplies and vin*-supply properties of our + * "simple-framebuffer" dt node. This is necessary so that we can make sure + * that any regulators needed by the display hardware 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 + * regulators. + * + * 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 regulator 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_regulators_init(struct simplefb_par *par, + struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct property *prop; + struct regulator *regulator; + const char *p; + int count = 0, i = 0, ret; + + if (dev_get_platdata(&pdev->dev) || !np) + return 0; + + /* Count the number of regulator supplies */ + for_each_property_of_node(np, prop) { + p = strstr(prop->name, SUPPLY_SUFFIX); + if (p && p != prop->name) + count++; + } + + if (!count) + return 0; + + par->regulators = devm_kcalloc(&pdev->dev, count, + sizeof(struct regulator *), GFP_KERNEL); + if (!par->regulators) + return -ENOMEM; + + /* Get all the regulators */ + for_each_property_of_node(np, prop) { + char name[32]; /* 32 is max size of property name */ + + p = strstr(prop->name, SUPPLY_SUFFIX); + if (!p || p == prop->name) + continue; + + strlcpy(name, prop->name, + strlen(prop->name) - strlen(SUPPLY_SUFFIX) + 1); + regulator = devm_regulator_get_optional(&pdev->dev, name); + if (IS_ERR(regulator)) { + if (PTR_ERR(regulator) == -EPROBE_DEFER) + return -EPROBE_DEFER; + dev_err(&pdev->dev, "regulator %s not found: %ld\n", + name, PTR_ERR(regulator)); + continue; + } + par->regulators[i++] = regulator; + } + par->regulator_count = i; + + /* Enable all the regulators */ + for (i = 0; i < par->regulator_count; i++) { + ret = regulator_enable(par->regulators[i]); + if (ret) { + dev_err(&pdev->dev, + "failed to enable regulator %d: %d\n", + i, ret); + devm_regulator_put(par->regulators[i]); + par->regulators[i] = NULL; + } + } + + return 0; +} + +static void simplefb_regulators_destroy(struct simplefb_par *par) +{ + int i; + + if (!par->regulators) + return; + + for (i = 0; i < par->regulator_count; i++) + if (par->regulators[i]) + regulator_disable(par->regulators[i]); +} +#else +static int simplefb_regulators_init(struct simplefb_par *par, + struct platform_device *pdev) { return 0; } +static void simplefb_regulators_destroy(struct simplefb_par *par) { } +#endif + static int simplefb_probe(struct platform_device *pdev) { int ret; @@ -340,6 +451,10 @@ static int simplefb_probe(struct platform_device *pdev) if (ret < 0) goto error_unmap; + ret = simplefb_regulators_init(par, pdev); + if (ret < 0) + goto error_clocks; + dev_info(&pdev->dev, "framebuffer at 0x%lx, 0x%x bytes, mapped to 0x%p\n", info->fix.smem_start, info->fix.smem_len, info->screen_base); @@ -351,13 +466,15 @@ static int simplefb_probe(struct platform_device *pdev) ret = register_framebuffer(info); if (ret < 0) { dev_err(&pdev->dev, "Unable to register simplefb: %d\n", ret); - goto error_clocks; + goto error_regulators; } dev_info(&pdev->dev, "fb%d: simplefb registered!\n", info->node); return 0; +error_regulators: + simplefb_regulators_destroy(par); error_clocks: simplefb_clocks_destroy(par); error_unmap: @@ -373,6 +490,7 @@ static int simplefb_remove(struct platform_device *pdev) struct simplefb_par *par = info->par; unregister_framebuffer(info); + simplefb_regulators_destroy(par); simplefb_clocks_destroy(par); framebuffer_release(info); -- cgit v1.2.3-54-g00ecf