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mtd: sh_flctl: Add power management with QoS request

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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: Bastian Hecht <hechtb@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
This commit is contained in:
Bastian Hecht 2012-03-18 15:13:20 +01:00 committed by David Woodhouse
parent 42d7fbe223
commit cfe781946d
2 changed files with 45 additions and 9 deletions
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51
drivers/mtd/nand/sh_flctl.c
View File

@ -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;

3
include/linux/mtd/sh_flctl.h
View File

@ -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 {