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mtd: rawnand: marvell: add suspend and resume hooks

PATCH New Daniel Mack 1 participant 3 messages Jul 8, 2018

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#0 lore raw

PATCH v4 1/3 mtd: rawnand: marvell: add suspend and resume hooks

This patch restores the suspend and resume hooks that the old driver used to have. Apart from stopping and starting the clocks, the resume callback also nullifies the selected_chip pointer, so the next command that is issued will re-select the chip and thereby restore the timing registers.

Factor out some code from marvell_nfc_init() into a new function marvell_nfc_reset() and also call it at resume time to reset some registers that don't retain their contents during low-power mode.

Without this patch, a PXA3xx based system would cough up an error similar to the one below after resume.

[   44.660162] marvell-nfc 43100000.nand-controller: Timeout waiting for  RB signal
[   44.671492] ubi0 error: ubi_io_write: error -110 while writing 2048 bytes to PEB 102:38912, written 0 bytes
[   44.682887] CPU: 0 PID: 1417 Comm: remote-control Not tainted 4.18.0-rc2+ #344
[   44.691197] Hardware name: Marvell PXA3xx (Device Tree Support)
[   44.697111] Backtrace:
[   44.699593] [<c0106458>] (dump_backtrace) from [<c0106718>] (show_stack+0x18/0x1c)
[   44.708931]  r7:00000800 r6:00009800 r5:00000066 r4:c6139000
[   44.715833] [<c0106700>] (show_stack) from [<c0678a60>] (dump_stack+0x20/0x28)
[   44.724206] [<c0678a40>] (dump_stack) from [<c0456cbc>] (ubi_io_write+0x3d4/0x630)
[   44.732925] [<c04568e8>] (ubi_io_write) from [<c0454428>] (ubi_eba_write_leb+0x690/0x6fc)

...

Fixes 02f26ecf8c77 ("mtd: nand: add reworked Marvell NAND controller driver")
---
 drivers/mtd/nand/raw/marvell_nand.c | 73 ++++++++++++++++++++++++-----
 1 file changed, 62 insertions(+), 11 deletions(-)
drivers/mtd/nand/raw/marvell_nand.c +62 -11
index 00d9f29bbdb6..03ee016d7516 100644
@@ -2662,6 +2662,21 @@ static int marvell_nfc_init_dma(struct marvell_nfc *nfc)
 	return 0;
 }
 
+static void marvell_nfc_reset(struct marvell_nfc *nfc)
+{
+	/*
+	 * ECC operations and interruptions are only enabled when specifically
+	 * needed. ECC shall not be activated in the early stages (fails probe).
+	 * Arbiter flag, even if marked as "reserved", must be set (empirical).
+	 * SPARE_EN bit must always be set or ECC bytes will not be at the same
+	 * offset in the read page and this will fail the protection.
+	 */
+	writel_relaxed(NDCR_ALL_INT | NDCR_ND_ARB_EN | NDCR_SPARE_EN |
+		       NDCR_RD_ID_CNT(NFCV1_READID_LEN), nfc->regs + NDCR);
+	writel_relaxed(0xFFFFFFFF, nfc->regs + NDSR);
+	writel_relaxed(0, nfc->regs + NDECCCTRL);
+}
+
 static int marvell_nfc_init(struct marvell_nfc *nfc)
 {
 	struct device_node *np = nfc->dev->of_node;
@@ -2700,17 +2715,7 @@ static int marvell_nfc_init(struct marvell_nfc *nfc)
 	if (!nfc->caps->is_nfcv2)
 		marvell_nfc_init_dma(nfc);
 
-	/*
-	 * ECC operations and interruptions are only enabled when specifically
-	 * needed. ECC shall not be activated in the early stages (fails probe).
-	 * Arbiter flag, even if marked as "reserved", must be set (empirical).
-	 * SPARE_EN bit must always be set or ECC bytes will not be at the same
-	 * offset in the read page and this will fail the protection.
-	 */
-	writel_relaxed(NDCR_ALL_INT | NDCR_ND_ARB_EN | NDCR_SPARE_EN |
-		       NDCR_RD_ID_CNT(NFCV1_READID_LEN), nfc->regs + NDCR);
-	writel_relaxed(0xFFFFFFFF, nfc->regs + NDSR);
-	writel_relaxed(0, nfc->regs + NDECCCTRL);
+	marvell_nfc_reset(nfc);
 
 	return 0;
 }
@@ -2825,6 +2830,51 @@ static int marvell_nfc_remove(struct platform_device *pdev)
 	return 0;
 }
 
+static int __maybe_unused marvell_nfc_suspend(struct device *dev)
+{
+	struct marvell_nfc *nfc = dev_get_drvdata(dev);
+	struct marvell_nand_chip *chip;
+
+	list_for_each_entry(chip, &nfc->chips, node)
+		marvell_nfc_wait_ndrun(&chip->chip);
+
+	clk_disable_unprepare(nfc->reg_clk);
+	clk_disable_unprepare(nfc->core_clk);
+
+	return 0;
+}
+
+static int __maybe_unused marvell_nfc_resume(struct device *dev)
+{
+	struct marvell_nfc *nfc = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(nfc->core_clk);
+	if (ret < 0)
+		return ret;
+
+	if (!IS_ERR(nfc->reg_clk)) {
+		ret = clk_prepare_enable(nfc->reg_clk);
+		if (ret < 0)
+			return ret;
+	}
+
+	/*
+	 * Reset nfc->selected_chip so the next command will cause the timing
+	 * registers to be restored in marvell_nfc_select_chip().
+	 */
+	nfc->selected_chip = NULL;
+
+	/* Reset registers that have lost their contents */
+	marvell_nfc_reset(nfc);
+
+	return 0;
+}
+
+static const struct dev_pm_ops marvell_nfc_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(marvell_nfc_suspend, marvell_nfc_resume)
+};
+
 static const struct marvell_nfc_caps marvell_armada_8k_nfc_caps = {
 	.max_cs_nb = 4,
 	.max_rb_nb = 2,
@@ -2909,6 +2959,7 @@ static struct platform_driver marvell_nfc_driver = {
 	.driver	= {
 		.name		= "marvell-nfc",
 		.of_match_table = marvell_nfc_of_ids,
+		.pm		= &marvell_nfc_pm_ops,
 	},
 	.id_table = marvell_nfc_platform_ids,
 	.probe = marvell_nfc_probe,
Signature · 1 line
2.17.1
#1 lore raw

PATCH v4 2/3 mtd: rawnand: marvell: remove bogus comment in marvell_nfc_select_chip()

The comment in marvell_nfc_select_chip() about ndtr0 and ndtr1 didn't reflect what the driver was doing.

The values of NDTR0 and NDTR1 are read from the registers at probe time and a copy is retained in 'struct marvell_nand_chip'. If keep-config is set in the DT properties, there are no other writers of these timing variables so they can safely be used when the chip is selected.

As suggested by Miquel Raynal, simply remove the comment.

---
 drivers/mtd/nand/raw/marvell_nand.c | 5 -----
 1 file changed, 5 deletions(-)
drivers/mtd/nand/raw/marvell_nand.c +0 -5
index 03ee016d7516..c395c5496d11 100644
@@ -650,11 +650,6 @@ static void marvell_nfc_select_chip(struct mtd_info *mtd, int die_nr)
 		return;
 	}
 
-	/*
-	 * Do not change the timing registers when using the DT property
-	 * marvell,nand-keep-config; in that case ->ndtr0 and ->ndtr1 from the
-	 * marvell_nand structure are supposedly empty.
-	 */
 	writel_relaxed(marvell_nand->ndtr0, nfc->regs + NDTR0);
 	writel_relaxed(marvell_nand->ndtr1, nfc->regs + NDTR1);
 
Signature · 1 line
2.17.1
#2 lore raw

PATCH v4 3/3 mtd: rawnand: marvell: set reg_clk to NULL if it can't be obtained

In reply to Daniel Mack

Don't keep an error-pointer around in the private struct. If this optional clock can't be obtained, simply set the pointer to NULL instead so we can use clk_prepare_enable() on it without further checks,

---
 drivers/mtd/nand/raw/marvell_nand.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)
drivers/mtd/nand/raw/marvell_nand.c +11 -11
index c395c5496d11..6b4665a98765 100644
@@ -2757,17 +2757,19 @@ static int marvell_nfc_probe(struct platform_device *pdev)
 		return ret;
 
 	nfc->reg_clk = devm_clk_get(&pdev->dev, "reg");
-	if (PTR_ERR(nfc->reg_clk) != -ENOENT) {
-		if (!IS_ERR(nfc->reg_clk)) {
-			ret = clk_prepare_enable(nfc->reg_clk);
-			if (ret)
-				goto unprepare_core_clk;
-		} else {
+	if (IS_ERR(nfc->reg_clk)) {
+		if (PTR_ERR(nfc->reg_clk) != -ENOENT) {
 			ret = PTR_ERR(nfc->reg_clk);
 			goto unprepare_core_clk;
 		}
+
+		nfc->reg_clk = NULL;
 	}
 
+	ret = clk_prepare_enable(nfc->reg_clk);
+	if (ret)
+		goto unprepare_core_clk;
+
 	marvell_nfc_disable_int(nfc, NDCR_ALL_INT);
 	marvell_nfc_clear_int(nfc, NDCR_ALL_INT);
 	ret = devm_request_irq(dev, irq, marvell_nfc_isr,
@@ -2848,11 +2850,9 @@ static int __maybe_unused marvell_nfc_resume(struct device *dev)
 	if (ret < 0)
 		return ret;
 
-	if (!IS_ERR(nfc->reg_clk)) {
-		ret = clk_prepare_enable(nfc->reg_clk);
-		if (ret < 0)
-			return ret;
-	}
+	ret = clk_prepare_enable(nfc->reg_clk);
+	if (ret < 0)
+		return ret;
 
 	/*
 	 * Reset nfc->selected_chip so the next command will cause the timing
Signature · 1 line
2.17.1