Commit ae1d2add authored by Lucas Stach's avatar Lucas Stach Committed by Shawn Guo
Browse files

soc: imx: gpcv2: handle reset clocks 



Some power domains handled by the GPCv2 driver need to enable the clocks
for devies inside the domain, so that the reset propagation and proper
power-up sequencing happens. Handle them in the same way as on GPCv1.

Signed-off-by: default avatarLucas Stach <l.stach@pengutronix.de>
Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
parent b798d5a1

Documentation/devicetree/bindings/power/fsl,imx-gpcv2.txt

+3 −0
Original line number Diff line number Diff line
@@ -32,6 +32,9 @@ Required properties: 
Optional properties:



- power-supply: Power supply used to power the domain

- clocks: a number of phandles to clocks that need to be enabled during

  domain power-up sequencing to ensure reset propagation into devices

  located inside this power domain



Example:

drivers/soc/imx/gpcv2.c

+59 −1
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ 
 * Copyright 2015-2017 Pengutronix, Lucas Stach <kernel@pengutronix.de>

 */



#include <linux/clk.h>

#include <linux/of_device.h>

#include <linux/platform_device.h>

#include <linux/pm_domain.h>
@@ -98,10 +99,14 @@ 


#define GPC_PGC_CTRL_PCR		BIT(0)



#define GPC_CLK_MAX		6



struct imx_pgc_domain {

	struct generic_pm_domain genpd;

	struct regmap *regmap;

	struct regulator *regulator;

	struct clk *clk[GPC_CLK_MAX];

	int num_clks;



	unsigned int pgc;
@@ -132,7 +137,7 @@ static int imx_gpc_pu_pgc_sw_pxx_req(struct generic_pm_domain *genpd, 
	const bool enable_power_control = !on;

	const bool has_regulator = !IS_ERR(domain->regulator);

	unsigned long deadline;

	int ret = 0;

	int i, ret = 0;



	regmap_update_bits(domain->regmap, GPC_PGC_CPU_MAPPING,

			   domain->bits.map, domain->bits.map);
@@ -145,6 +150,10 @@ static int imx_gpc_pu_pgc_sw_pxx_req(struct generic_pm_domain *genpd, 
		}

	}



	/* Enable reset clocks for all devices in the domain */

	for (i = 0; i < domain->num_clks; i++)

		clk_prepare_enable(domain->clk[i]);



	if (enable_power_control)

		regmap_update_bits(domain->regmap, GPC_PGC_CTRL(domain->pgc),

				   GPC_PGC_CTRL_PCR, GPC_PGC_CTRL_PCR);
@@ -190,6 +199,10 @@ static int imx_gpc_pu_pgc_sw_pxx_req(struct generic_pm_domain *genpd, 
		regmap_update_bits(domain->regmap, GPC_PGC_CTRL(domain->pgc),

				   GPC_PGC_CTRL_PCR, 0);



	/* Disable reset clocks for all devices in the domain */

	for (i = 0; i < domain->num_clks; i++)

		clk_disable_unprepare(domain->clk[i]);



	if (has_regulator && !on) {

		int err;
@@ -440,6 +453,41 @@ static const struct imx_pgc_domain_data imx8m_pgc_domain_data = { 
	.reg_access_table = &imx8m_access_table,

};



static int imx_pgc_get_clocks(struct imx_pgc_domain *domain)

{

	int i, ret;



	for (i = 0; ; i++) {

		struct clk *clk = of_clk_get(domain->dev->of_node, i);

		if (IS_ERR(clk))

			break;

		if (i >= GPC_CLK_MAX) {

			dev_err(domain->dev, "more than %d clocks\n",

				GPC_CLK_MAX);

			ret = -EINVAL;

			goto clk_err;

		}

		domain->clk[i] = clk;

	}

	domain->num_clks = i;



	return 0;



clk_err:

	while (i--)

		clk_put(domain->clk[i]);



	return ret;

}



static void imx_pgc_put_clocks(struct imx_pgc_domain *domain)

{

	int i;



	for (i = domain->num_clks - 1; i >= 0; i--)

		clk_put(domain->clk[i]);

}



static int imx_pgc_domain_probe(struct platform_device *pdev)

{

	struct imx_pgc_domain *domain = pdev->dev.platform_data;
@@ -459,9 +507,17 @@ static int imx_pgc_domain_probe(struct platform_device *pdev) 
				      domain->voltage, domain->voltage);

	}



	ret = imx_pgc_get_clocks(domain);

	if (ret) {

		if (ret != -EPROBE_DEFER)

			dev_err(domain->dev, "Failed to get domain's clocks\n");

		return ret;

	}



	ret = pm_genpd_init(&domain->genpd, NULL, true);

	if (ret) {

		dev_err(domain->dev, "Failed to init power domain\n");

		imx_pgc_put_clocks(domain);

		return ret;

	}
@@ -470,6 +526,7 @@ static int imx_pgc_domain_probe(struct platform_device *pdev) 
	if (ret) {

		dev_err(domain->dev, "Failed to add genpd provider\n");

		pm_genpd_remove(&domain->genpd);

		imx_pgc_put_clocks(domain);

	}



	return ret;
@@ -481,6 +538,7 @@ static int imx_pgc_domain_remove(struct platform_device *pdev) 


	of_genpd_del_provider(domain->dev->of_node);

	pm_genpd_remove(&domain->genpd);

	imx_pgc_put_clocks(domain);



	return 0;

}

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