Commit 92a511a5 authored by Thierry Reding's avatar Thierry Reding Committed by Hans de Goede
Browse files

fbdev/simplefb: Add support for generic power-domains 



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: default avatarThierry Reding <treding@nvidia.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231101172017.3872242-3-thierry.reding@gmail.com
parent 8ddfc01a

drivers/video/fbdev/simplefb.c

+93 −0
Original line number Diff line number Diff line
@@ -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);