[PATCHv2] mtd: nand: atmel_nand: retrieve NFC clock

Alexandre Belloni
2014-09-11T17:52:39Z

From: Boris BREZILLON <boris.brezillon@free-electrons.com>

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

Changes in v2:
- reworked the error path to really make the clock optional
- Documented the new optional property

.../devicetree/bindings/mtd/atmel-nand.txt | 1 +
drivers/mtd/nand/atmel_nand.c | 25 ++++++++++++++++++++++
2 files changed, 26 insertions(+)

diff --git a/Documentation/devicetree/bindings/mtd/atmel-nand.txt b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
index c4728839d0c1..f71e2ebab15b 100644
--- a/Documentation/devicetree/bindings/mtd/atmel-nand.txt
+++ b/Documentation/devicetree/bindings/mtd/atmel-nand.txt
@@ -38,6 +38,7 @@ Optional properties:
if don't want to use it.
- Optional properties:
- atmel,write-by-sram: boolean to enable NFC write by sram.
+ - clocks: phandle to the peripheral clock if it exists

Examples:
nand0: nand@40000000,0 {
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index 9c5f717bda54..69e0eb1ace54 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);
@@ -2281,6 +2285,26 @@ static int atmel_nand_nfc_probe(struct platform_device *pdev)

nfc->is_initialized = true;
dev_info(&pdev->dev, "NFC is probed.\n");
+
+ 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 is missing");
+ }
+
+ 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