[PATCHv4] mtd: nand: atmel_nand: retrieve NFC clock

From: Alexandre Belloni
Date: Fri Sep 12 2014 - 05:40:23 EST


From: Boris BREZILLON <boris.brezillon@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Boris BREZILLON <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
---

Changes in v4:
- fix typo in the documentation

.../devicetree/bindings/mtd/atmel-nand.txt | 2 ++
drivers/mtd/nand/atmel_nand.c | 25 ++++++++++++++++++++++
2 files changed, 27 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index c4728839d0c1..6edc3b616e98 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -36,6 +36,7 @@ Optional properties:
- reg : should specify the address and size used for NFC command registers,
NFC registers and NFC Sram. NFC Sram address and size can be absent
if don't want to use it.
+ - clocks: phandle to the peripheral clock
- Optional properties:
- atmel,write-by-sram: boolean to enable NFC write by sram.

@@ -98,6 +99,7 @@ nand0: nand@40000000 {
compatible = "atmel,sama5d3-nfc";
#address-cells = <1>;
#size-cells = <1>;
+ clocks = <&hsmc_clk>
reg = <
0x70000000 0x10000000 /* NFC Command Registers */
0xffffc000 0x00000070 /* NFC HSMC regs */
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 9c5f717bda54..d1e502f8dbd0 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -27,6 +27,7 @@
*
*/

+#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>
#include <linux/module.h>
@@ -96,6 +97,8 @@ struct atmel_nfc {
bool use_nfc_sram;
bool write_by_sram;

+ struct clk *clk;
+
bool is_initialized;
struct completion comp_ready;
struct completion comp_cmd_done;
@@ -2248,6 +2251,7 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
{
struct atmel_nfc *nfc = &nand_nfc;
struct resource *nfc_cmd_regs, *nfc_hsmc_regs, *nfc_sram;
+ int ret;

nfc_cmd_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
nfc->base_cmd_regs = devm_ioremap_resource(&pdev->dev, nfc_cmd_regs);
@@ -2279,8 +2283,28 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)
nfc_writel(nfc->hsmc_regs, IDR, 0xffffffff);
nfc_readl(nfc->hsmc_regs, SR); /* clear the NFC_SR */

+ nfc->clk = devm_clk_get(&pdev->dev, NULL);
+ if (!IS_ERR(nfc->clk)) {
+ ret = clk_prepare_enable(nfc->clk);
+ if (ret)
+ return ret;
+ } else {
+ dev_warn(&pdev->dev, "NFC clock missing, update your Device Tree");
+ }
+
nfc->is_initialized = true;
dev_info(&pdev->dev, "NFC is probed.\n");
+
+ return 0;
+}
+
+static int atmel_nand_nfc_remove(struct platform_device *pdev)
+{
+ struct atmel_nfc *nfc = &nand_nfc;
+
+ if (!IS_ERR(nfc->clk))
+ clk_disable_unprepare(nfc->clk);
+
return 0;
}

@@ -2297,6 +2321,7 @@ static struct platform_driver atmel_nand_nfc_driver = {
.of_match_table = of_match_ptr(atmel_nand_nfc_match),
},
.probe = atmel_nand_nfc_probe,
+ .remove = atmel_nand_nfc_remove,
};

static struct platform_driver atmel_nand_driver = {
--
1.9.1

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