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Commit cfe78194 authored by Bastian Hecht's avatar Bastian Hecht Committed by David Woodhouse
Browse files

mtd: sh_flctl: Add power management with QoS request 



Adds power management code with fine granularity. Every flash control
command is enclosed by runtime_put()/get()s. To make sure that no
overhead is generated by too frequent power state switches, a quality of
service request is issued.

Signed-off-by: default avatarBastian Hecht <hechtb@gmail.com>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 42d7fbe2

drivers/mtd/nand/sh_flctl.c

+42 −9
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ 
#include <linux/delay.h>

#include <linux/io.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>

#include <linux/slab.h>



#include <linux/mtd/mtd.h>
@@ -515,6 +516,8 @@ static void flctl_cmdfunc(struct mtd_info *mtd, unsigned int command, 
	struct sh_flctl *flctl = mtd_to_flctl(mtd);

	uint32_t read_cmd = 0;



	pm_runtime_get_sync(&flctl->pdev->dev);



	flctl->read_bytes = 0;

	if (command != NAND_CMD_PAGEPROG)

		flctl->index = 0;
@@ -670,7 +673,7 @@ static void flctl_cmdfunc(struct mtd_info *mtd, unsigned int command, 
	default:

		break;

	}

	return;

	goto runtime_exit;



read_normal_exit:

	writel(flctl->read_bytes, FLDTCNTR(flctl));	/* set read size */
@@ -678,23 +681,47 @@ read_normal_exit: 
	start_translation(flctl);

	read_fiforeg(flctl, flctl->read_bytes, 0);

	wait_completion(flctl);

runtime_exit:

	pm_runtime_put_sync(&flctl->pdev->dev);

	return;

}



static void flctl_select_chip(struct mtd_info *mtd, int chipnr)

{

	struct sh_flctl *flctl = mtd_to_flctl(mtd);

	int ret;



	switch (chipnr) {

	case -1:

		flctl->flcmncr_base &= ~CE0_ENABLE;



		pm_runtime_get_sync(&flctl->pdev->dev);

		writel(flctl->flcmncr_base, FLCMNCR(flctl));



		if (flctl->qos_request) {

			dev_pm_qos_remove_request(&flctl->pm_qos);

			flctl->qos_request = 0;

		}



		pm_runtime_put_sync(&flctl->pdev->dev);

		break;

	case 0:

		flctl->flcmncr_base |= CE0_ENABLE;

		writel(flctl->flcmncr_base, FLCMNCR(flctl));

		if (flctl->holden)



		if (!flctl->qos_request) {

			ret = dev_pm_qos_add_request(&flctl->pdev->dev,

							&flctl->pm_qos, 100);

			if (ret < 0)

				dev_err(&flctl->pdev->dev,

					"PM QoS request failed: %d\n", ret);

			flctl->qos_request = 1;

		}



		if (flctl->holden) {

			pm_runtime_get_sync(&flctl->pdev->dev);

			writel(HOLDEN, FLHOLDCR(flctl));

			pm_runtime_put_sync(&flctl->pdev->dev);

		}

		break;

	default:

		BUG();
@@ -835,13 +862,13 @@ static int __devinit flctl_probe(struct platform_device *pdev) 
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (!res) {

		dev_err(&pdev->dev, "failed to get I/O memory\n");

		goto err;

		goto err_iomap;

	}



	flctl->reg = ioremap(res->start, resource_size(res));

	if (flctl->reg == NULL) {

		dev_err(&pdev->dev, "failed to remap I/O memory\n");

		goto err;

		goto err_iomap;

	}



	platform_set_drvdata(pdev, flctl);
@@ -871,23 +898,28 @@ static int __devinit flctl_probe(struct platform_device *pdev) 
		nand->read_word = flctl_read_word;

	}



	pm_runtime_enable(&pdev->dev);

	pm_runtime_resume(&pdev->dev);



	ret = nand_scan_ident(flctl_mtd, 1, NULL);

	if (ret)

		goto err;

		goto err_chip;



	ret = flctl_chip_init_tail(flctl_mtd);

	if (ret)

		goto err;

		goto err_chip;



	ret = nand_scan_tail(flctl_mtd);

	if (ret)

		goto err;

		goto err_chip;



	mtd_device_register(flctl_mtd, pdata->parts, pdata->nr_parts);



	return 0;



err:

err_chip:

	pm_runtime_disable(&pdev->dev);

err_iomap:

	kfree(flctl);

	return ret;

}
@@ -897,6 +929,7 @@ static int __devexit flctl_remove(struct platform_device *pdev) 
	struct sh_flctl *flctl = platform_get_drvdata(pdev);



	nand_release(&flctl->mtd);

	pm_runtime_disable(&pdev->dev);

	kfree(flctl);



	return 0;

include/linux/mtd/sh_flctl.h

+3 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/mtd/mtd.h>

#include <linux/mtd/nand.h>

#include <linux/mtd/partitions.h>

#include <linux/pm_qos.h>



/* FLCTL registers */

#define FLCMNCR(f)		(f->reg + 0x0)
@@ -131,6 +132,7 @@ struct sh_flctl { 
	struct mtd_info		mtd;

	struct nand_chip	chip;

	struct platform_device	*pdev;

	struct dev_pm_qos_request pm_qos;

	void __iomem		*reg;



	uint8_t	done_buff[2048 + 64];	/* max size 2048 + 64 */
@@ -149,6 +151,7 @@ struct sh_flctl { 
	unsigned page_size:1;	/* NAND page size (0 = 512, 1 = 2048) */

	unsigned hwecc:1;	/* Hardware ECC (0 = disabled, 1 = enabled) */

	unsigned holden:1;	/* Hardware has FLHOLDCR and HOLDEN is set */

	unsigned qos_request:1;	/* QoS request to prevent deep power shutdown */

};



struct sh_flctl_platform_data {