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: Bastian Hecht <hechtb@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
diff --git a/drivers/mtd/nand/sh_flctl.c b/drivers/mtd/nand/sh_flctl.c
index d0f1f3c..2ee9a1b 100644
--- a/drivers/mtd/nand/sh_flctl.c
+++ b/drivers/mtd/nand/sh_flctl.c
@@ -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 @@
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 @@
default:
break;
}
- return;
+ goto runtime_exit;
read_normal_exit:
writel(flctl->read_bytes, FLDTCNTR(flctl)); /* set read size */
@@ -678,23 +681,47 @@
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 @@
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 @@
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 @@
struct sh_flctl *flctl = platform_get_drvdata(pdev);
nand_release(&flctl->mtd);
+ pm_runtime_disable(&pdev->dev);
kfree(flctl);
return 0;