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Commit 596e7955 authored by Faiz Abbas's avatar Faiz Abbas Committed by Tony Lindgren
Browse files

bus: ti-sysc: Add support for software reset 



Add support for the software reset of a target interconnect
module using its sysconfig and sysstatus registers.

Signed-off-by: default avatarFaiz Abbas <faiz_abbas@ti.com>
[tony@atomide.com: updated to check if sysconfig exists]
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
parent 7f35e63d

drivers/bus/ti-sysc.c

+46 −0
Original line number Diff line number Diff line
@@ -23,11 +23,14 @@ 
#include <linux/of_address.h>

#include <linux/of_platform.h>

#include <linux/slab.h>

#include <linux/iopoll.h>



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



#include <dt-bindings/bus/ti-sysc.h>



#define MAX_MODULE_SOFTRESET_WAIT		10000



static const char * const reg_names[] = { "rev", "sysc", "syss", };



enum sysc_clocks {
@@ -88,6 +91,11 @@ struct sysc { 
	struct delayed_work idle_work;

};



void sysc_write(struct sysc *ddata, int offset, u32 value)

{

	writel_relaxed(value, ddata->module_va + offset);

}



static u32 sysc_read(struct sysc *ddata, int offset)

{

	if (ddata->cfg.quirks & SYSC_QUIRK_16BIT) {
@@ -943,6 +951,36 @@ static void sysc_init_revision_quirks(struct sysc *ddata) 
	}

}



static int sysc_reset(struct sysc *ddata)

{

	int offset = ddata->offsets[SYSC_SYSCONFIG];

	int val;



	if (ddata->legacy_mode || offset < 0 ||

	    ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT)

		return 0;



	/*

	 * Currently only support reset status in sysstatus.

	 * Warn and return error in all other cases

	 */

	if (!ddata->cfg.syss_mask) {

		dev_err(ddata->dev, "No ti,syss-mask. Reset failed\n");

		return -EINVAL;

	}



	val = sysc_read(ddata, offset);

	val |= (0x1 << ddata->cap->regbits->srst_shift);

	sysc_write(ddata, offset, val);



	/* Poll on reset status */

	offset = ddata->offsets[SYSC_SYSSTATUS];



	return readl_poll_timeout(ddata->module_va + offset, val,

				  (val & ddata->cfg.syss_mask) == 0x0,

				  100, MAX_MODULE_SOFTRESET_WAIT);

}



/* At this point the module is configured enough to read the revision */

static int sysc_init_module(struct sysc *ddata)

{
@@ -960,6 +998,14 @@ static int sysc_init_module(struct sysc *ddata) 
		return 0;

	}



	error = sysc_reset(ddata);

	if (error) {

		dev_err(ddata->dev, "Reset failed with %d\n", error);

		pm_runtime_put_sync(ddata->dev);



		return error;

	}



	ddata->revision = sysc_read_revision(ddata);

	pm_runtime_put_sync(ddata->dev);