[PATCH v3 14/16] mtd/docg3: add suspend and resume

From: Robert Jarzmik
Date: Sat Nov 19 2011 - 10:04:25 EST


Add functions to powerdown and powerup from suspend, in
order to save power.

Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
---
drivers/mtd/devices/docg3.c | 75 ++++++++++++++++++++++++++++++++++++++++++-
drivers/mtd/devices/docg3.h | 6 +++
2 files changed, 80 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c
index 26cc179..d94c759 100644
--- a/drivers/mtd/devices/docg3.c
+++ b/drivers/mtd/devices/docg3.c
@@ -45,7 +45,6 @@
* As no specification is available from M-Systems/Sandisk, this drivers lacks
* several functions available on the chip, as :
* - IPL write
- * - powerdown / powerup
*
* The bus data width (8bits versus 16bits) is not handled (if_cfg flag), and
* the driver assumes a 16bits data bus.
@@ -1756,6 +1755,78 @@ static void doc_release_device(struct mtd_info *mtd)
}

/**
+ * docg3_resume - Awakens docg3 floor
+ * @pdev: platfrom device
+ *
+ * Returns 0 (always successfull)
+ */
+static int docg3_resume(struct platform_device *pdev)
+{
+ int i;
+ struct mtd_info **docg3_floors, *mtd;
+ struct docg3 *docg3;
+
+ docg3_floors = platform_get_drvdata(pdev);
+ mtd = docg3_floors[0];
+ docg3 = mtd->priv;
+
+ doc_dbg("docg3_resume()\n");
+ for (i = 0; i < 12; i++)
+ doc_readb(docg3, DOC_IOSPACE_IPL);
+ return 0;
+}
+
+/**
+ * docg3_suspend - Put in low power mode the docg3 floor
+ * @pdev: platform device
+ * @state: power state
+ *
+ * Shuts off most of docg3 circuitery to lower power consumption.
+ *
+ * Returns 0 if suspend succeeded, -EIO if chip refused suspend
+ */
+static int docg3_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ int floor, i;
+ struct mtd_info **docg3_floors, *mtd;
+ struct docg3 *docg3;
+ u8 ctrl, pwr_down;
+
+ docg3_floors = platform_get_drvdata(pdev);
+ for (floor = 0; floor < DOC_MAX_NBFLOORS; floor++) {
+ mtd = docg3_floors[floor];
+ if (!mtd)
+ continue;
+ docg3 = mtd->priv;
+
+ doc_writeb(docg3, floor, DOC_DEVICESELECT);
+ ctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);
+ ctrl &= ~DOC_CTRL_VIOLATION & ~DOC_CTRL_CE;
+ doc_writeb(docg3, ctrl, DOC_FLASHCONTROL);
+
+ for (i = 0; i < 10; i++) {
+ usleep_range(3000, 4000);
+ pwr_down = doc_register_readb(docg3, DOC_POWERMODE);
+ if (pwr_down & DOC_POWERDOWN_READY)
+ break;
+ }
+ if (pwr_down & DOC_POWERDOWN_READY) {
+ doc_dbg("docg3_suspend(): floor %d powerdown ok\n",
+ floor);
+ } else {
+ doc_err("docg3_suspend(): floor %d powerdown failed\n",
+ floor);
+ return -EIO;
+ }
+ }
+
+ mtd = docg3_floors[0];
+ docg3 = mtd->priv;
+ doc_set_asic_mode(docg3, DOC_ASICMODE_POWERDOWN);
+ return 0;
+}
+
+/**
* doc_probe - Probe the IO space for a DiskOnChip G3 chip
* @pdev: platform device
*
@@ -1860,6 +1931,8 @@ static struct platform_driver g3_driver = {
.name = "docg3",
.owner = THIS_MODULE,
},
+ .suspend = docg3_suspend,
+ .resume = docg3_resume,
.remove = __exit_p(docg3_release),
};

diff --git a/drivers/mtd/devices/docg3.h b/drivers/mtd/devices/docg3.h
index 33db727..cd70b18 100644
--- a/drivers/mtd/devices/docg3.h
+++ b/drivers/mtd/devices/docg3.h
@@ -127,6 +127,7 @@

#define DOC_ASICMODECONFIRM 0x1072
#define DOC_CHIPID_INV 0x1074
+#define DOC_POWERMODE 0x107c

/*
* Flash sequences
@@ -239,6 +240,11 @@
#define DOC_READADDR_ADDR_MASK 0x1fff

/*
+ * Flash register : DOC_POWERMODE
+ */
+#define DOC_POWERDOWN_READY 0x80
+
+/*
* Status of erase and write operation
*/
#define DOC_PLANES_STATUS_FAIL 0x01
--
1.7.5.4

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