From: Thierry Reding <treding@xxxxxxxxxx>
The simple-framebuffer device tree bindings document the power-domains
property, so make sure that simplefb supports it. This ensures that the
power domains remain enabled as long as simplefb is active.
v2: - remove unnecessary call to simplefb_detach_genpds() since that's
already done automatically by devres
- fix crash if power-domains property is missing in DT
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/video/fbdev/simplefb.c | 93 ++++++++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)
diff --git a/drivers/video/fbdev/simplefb.c b/drivers/video/fbdev/simplefb.c
index 18025f34fde7..fe682af63827 100644
--- a/drivers/video/fbdev/simplefb.c
+++ b/drivers/video/fbdev/simplefb.c
@@ -25,6 +25,7 @@
#include <linux/of_clk.h>
#include <linux/of_platform.h>
#include <linux/parser.h>
+#include <linux/pm_domain.h>
#include <linux/regulator/consumer.h>
static const struct fb_fix_screeninfo simplefb_fix = {
@@ -78,6 +79,11 @@ struct simplefb_par {
unsigned int clk_count;
struct clk **clks;
#endif
+#if defined CONFIG_OF && defined CONFIG_PM_GENERIC_DOMAINS
+ unsigned int num_genpds;
+ struct device **genpds;
+ struct device_link **genpd_links;
+#endif
#if defined CONFIG_OF && defined CONFIG_REGULATOR
bool regulators_enabled;
u32 regulator_count;
@@ -432,6 +438,89 @@ static void simplefb_regulators_enable(struct simplefb_par *par,
static void simplefb_regulators_destroy(struct simplefb_par *par) { }
#endif
+#if defined CONFIG_OF && defined CONFIG_PM_GENERIC_DOMAINS
+static void simplefb_detach_genpds(void *res)
+{
+ struct simplefb_par *par = res;
+ unsigned int i = par->num_genpds;
+
+ if (par->num_genpds <= 1)
+ return;
+
+ while (i--) {
+ if (par->genpd_links[i])
+ device_link_del(par->genpd_links[i]);
+
+ if (!IS_ERR_OR_NULL(par->genpds[i]))
+ dev_pm_domain_detach(par->genpds[i], true);
+ }
+}
+
+static int simplefb_attach_genpds(struct simplefb_par *par,
+ struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ unsigned int i;
+ int err;
+
+ err = of_count_phandle_with_args(dev->of_node, "power-domains",
+ "#power-domain-cells");
+ if (err < 0) {
+ dev_info(dev, "failed to parse power-domains: %d\n", err);
+ return err;
+ }
+
+ par->num_genpds = err;
+
+ /*
+ * Single power-domain devices are handled by the driver core, so
+ * nothing to do here.
+ */
+ if (par->num_genpds <= 1)
+ return 0;
+
+ par->genpds = devm_kcalloc(dev, par->num_genpds, sizeof(*par->genpds),
+ GFP_KERNEL);
+ if (!par->genpds)
+ return -ENOMEM;
+
+ par->genpd_links = devm_kcalloc(dev, par->num_genpds,
+ sizeof(*par->genpd_links),
+ GFP_KERNEL);
+ if (!par->genpd_links)
+ return -ENOMEM;
+
+ for (i = 0; i < par->num_genpds; i++) {
+ par->genpds[i] = dev_pm_domain_attach_by_id(dev, i);
+ if (IS_ERR(par->genpds[i])) {
+ err = PTR_ERR(par->genpds[i]);
+ if (err == -EPROBE_DEFER) {
+ simplefb_detach_genpds(par);
+ return err;
+ }
+
+ dev_warn(dev, "failed to attach domain %u: %d\n", i, err);
+ continue;
+ }
+
+ par->genpd_links[i] = device_link_add(dev, par->genpds[i],
+ DL_FLAG_STATELESS |
+ DL_FLAG_PM_RUNTIME |
+ DL_FLAG_RPM_ACTIVE);
+ if (!par->genpd_links[i])
+ dev_warn(dev, "failed to link power-domain %u\n", i);
+ }
+
+ return devm_add_action_or_reset(dev, simplefb_detach_genpds, par);
+}
+#else
+static int simplefb_attach_genpds(struct simplefb_par *par,
+ struct platform_device *pdev)
+{
+ return 0;
+}
+#endif
+
static int simplefb_probe(struct platform_device *pdev)
{
int ret;
@@ -518,6 +607,10 @@ static int simplefb_probe(struct platform_device *pdev)
if (ret < 0)
goto error_clocks;
+ ret = simplefb_attach_genpds(par, pdev);
+ if (ret < 0)
+ goto error_regulators;
+
simplefb_clocks_enable(par, pdev);
simplefb_regulators_enable(par, pdev);
--
2.42.0
