Commit d30cd83f authored by Tero Kristo's avatar Tero Kristo Committed by Santosh Shilimkar
Browse files

soc: ti: omap-prm: add support for denying idle for reset clockdomain 



TI SoCs hardware reset signals require the parent clockdomain to be
in force wakeup mode while de-asserting the reset, otherwise it may
never complete. To support this, add pdata hooks to control the
clockdomain directly.

Signed-off-by: default avatarTero Kristo <t-kristo@ti.com>
Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
Signed-off-by: default avatarSantosh Shilimkar <santosh.shilimkar@oracle.com>
parent c5117a78

drivers/soc/ti/omap_prm.c

+34 −2
Original line number Diff line number Diff line
@@ -16,6 +16,8 @@ 
#include <linux/reset-controller.h>

#include <linux/delay.h>



#include <linux/platform_data/ti-prm.h>



struct omap_rst_map {

	s8 rst;

	s8 st;
@@ -24,6 +26,7 @@ struct omap_rst_map { 
struct omap_prm_data {

	u32 base;

	const char *name;

	const char *clkdm_name;

	u16 rstctrl;

	u16 rstst;

	const struct omap_rst_map *rstmap;
@@ -40,6 +43,8 @@ struct omap_reset_data { 
	struct omap_prm *prm;

	u32 mask;

	spinlock_t lock;

	struct clockdomain *clkdm;

	struct device *dev;

};



#define to_omap_reset_data(p) container_of((p), struct omap_reset_data, rcdev)
@@ -49,6 +54,7 @@ struct omap_reset_data { 


#define OMAP_PRM_HAS_RSTCTRL	BIT(0)

#define OMAP_PRM_HAS_RSTST	BIT(1)

#define OMAP_PRM_HAS_NO_CLKDM	BIT(2)



#define OMAP_PRM_HAS_RESETS	(OMAP_PRM_HAS_RSTCTRL | OMAP_PRM_HAS_RSTST)
@@ -133,6 +139,8 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, 
	int st_bit;

	bool has_rstst;

	unsigned long flags;

	struct ti_prm_platform_data *pdata = dev_get_platdata(reset->dev);

	int ret = 0;



	has_rstst = reset->prm->data->rstst ||

		(reset->prm->data->flags & OMAP_PRM_HAS_RSTST);
@@ -145,6 +153,9 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, 
		writel_relaxed(v, reset->prm->base + reset->prm->data->rstst);

	}



	if (reset->clkdm)

		pdata->clkdm_deny_idle(reset->clkdm);



	/* de-assert the reset control line */

	spin_lock_irqsave(&reset->lock, flags);

	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctrl);
@@ -153,7 +164,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, 
	spin_unlock_irqrestore(&reset->lock, flags);



	if (!has_rstst)

		return 0;

		goto exit;



	/* wait for the status to be set */

	ret = readl_relaxed_poll_timeout(reset->prm->base +
@@ -164,7 +175,11 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, 
		pr_err("%s: timedout waiting for %s:%lu\n", __func__,

		       reset->prm->data->name, id);



	return 0;

exit:

	if (reset->clkdm)

		pdata->clkdm_allow_idle(reset->clkdm);



	return ret;

}



static const struct reset_control_ops omap_reset_ops = {
@@ -189,6 +204,8 @@ static int omap_prm_reset_init(struct platform_device *pdev, 
{

	struct omap_reset_data *reset;

	const struct omap_rst_map *map;

	struct ti_prm_platform_data *pdata = dev_get_platdata(&pdev->dev);

	char buf[32];



	/*

	 * Check if we have controllable resets. If either rstctrl is non-zero
@@ -198,6 +215,11 @@ static int omap_prm_reset_init(struct platform_device *pdev, 
	if (!prm->data->rstctrl && !(prm->data->flags & OMAP_PRM_HAS_RSTCTRL))

		return 0;



	/* Check if we have the pdata callbacks in place */

	if (!pdata || !pdata->clkdm_lookup || !pdata->clkdm_deny_idle ||

	    !pdata->clkdm_allow_idle)

		return -EINVAL;



	map = prm->data->rstmap;

	if (!map)

		return -EINVAL;
@@ -212,10 +234,20 @@ static int omap_prm_reset_init(struct platform_device *pdev, 
	reset->rcdev.nr_resets = OMAP_MAX_RESETS;

	reset->rcdev.of_xlate = omap_prm_reset_xlate;

	reset->rcdev.of_reset_n_cells = 1;

	reset->dev = &pdev->dev;

	spin_lock_init(&reset->lock);



	reset->prm = prm;



	sprintf(buf, "%s_clkdm", prm->data->clkdm_name ? prm->data->clkdm_name :

		prm->data->name);



	if (!(prm->data->flags & OMAP_PRM_HAS_NO_CLKDM)) {

		reset->clkdm = pdata->clkdm_lookup(buf);

		if (!reset->clkdm)

			return -EINVAL;

	}



	while (map->rst >= 0) {

		reset->mask |= BIT(map->rst);

		map++;

include/linux/platform_data/ti-prm.h

0 → 100644
+21 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * TI PRM (Power & Reset Manager) platform data

 *

 * Copyright (C) 2019 Texas Instruments, Inc.

 *

 * Tero Kristo <t-kristo@ti.com>

 */



#ifndef _LINUX_PLATFORM_DATA_TI_PRM_H

#define _LINUX_PLATFORM_DATA_TI_PRM_H



struct clockdomain;



struct ti_prm_platform_data {

	void (*clkdm_deny_idle)(struct clockdomain *clkdm);

	void (*clkdm_allow_idle)(struct clockdomain *clkdm);

	struct clockdomain * (*clkdm_lookup)(const char *name);

};



#endif /* _LINUX_PLATFORM_DATA_TI_PRM_H */