| Message ID | 1445563918-1050-3-git-send-email-wens@csie.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 23, 2015 at 9:31 AM, Chen-Yu Tsai <wens@csie.org> wrote: > This claims and enables regulators listed in the simple framebuffer dt > node. This is needed so that regulators powering the display pipeline > and external hardware, described in the device node and known by the > kernel code, will remain properly enabled. > > Signed-off-by: Chen-Yu Tsai <wens@csie.org> > Reviewed-by: Hans de Goede <hdegoede@redhat.com> > Acked-by: Mark Brown <broonie@kernel.org> > --- > drivers/video/fbdev/simplefb.c | 120 ++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 119 insertions(+), 1 deletion(-) > > diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c > index 52c5c7e63b52..9de34ee15ac0 100644 > --- a/drivers/video/fbdev/simplefb.c > +++ b/drivers/video/fbdev/simplefb.c > @@ -28,7 +28,10 @@ > #include <linux/platform_device.h> > #include <linux/clk.h> > #include <linux/clk-provider.h> > +#include <linux/of.h> > #include <linux/of_platform.h> > +#include <linux/parser.h> > +#include <linux/regulator/consumer.h> > > 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) Sorry, the test is completely reversed here. > + continue; > + > + strlcpy(name, prop->name, > + strlen(prop->name) - sizeof(SUPPLY_SUFFIX) + 1); And string length is off by 1 due to using sizeof here. I'll send a new version. Sorry for the noise. ChenYu > + 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); > > -- > 2.6.1 >
diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c index 52c5c7e63b52..9de34ee15ac0 100644 --- a/drivers/video/fbdev/simplefb.c +++ b/drivers/video/fbdev/simplefb.c @@ -28,7 +28,10 @@ #include <linux/platform_device.h> #include <linux/clk.h> #include <linux/clk-provider.h> +#include <linux/of.h> #include <linux/of_platform.h> +#include <linux/parser.h> +#include <linux/regulator/consumer.h> 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) - sizeof(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);