From 839ad403a2d8081a6c15f6fc2836b01919338f3c Mon Sep 17 00:00:00 2001
From: Andrey Shvetsov <andrey.shvetsov@k2l.de>
Date: Mon, 12 Feb 2018 12:24:37 +0100
Subject: [PATCH] staging: most: dim2: read clock speed from the device tree
This implements reading of the clock speed parameter from the device
tree.
Signed-off-by: Andrey Shvetsov <andrey.shvetsov@k2l.de>
---
Documentation/devicetree/bindings/inic/microchip,inic-dim2.txt | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
hdm-dim2/dim2_hdm.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 113 insertions(+), 1 deletion(-)
create mode 100644 Documentation/devicetree/bindings/inic/microchip,inic-dim2.txt
diff --git a/hdm-dim2/dim2_hdm.c b/hdm-dim2/dim2_hdm.c
index 2dba917..05e1896 100644
--- a/hdm-dim2/dim2_hdm.c
+++ b/hdm-dim2/dim2_hdm.c
@@ -698,6 +698,42 @@ static void dma_free(struct mbo *mbo, u32 size)
static const struct of_device_id dim2_of_match[];
+static struct {
+ const char *clock_speed;
+ u8 clk_speed;
+} clk_mt[] = {
+ { "256fs", CLK_256FS },
+ { "512fs", CLK_512FS },
+ { "1024fs", CLK_1024FS },
+ { "2048fs", CLK_2048FS },
+ { "3072fs", CLK_3072FS },
+ { "4096fs", CLK_4096FS },
+ { "6144fs", CLK_6144FS },
+ { "8192fs", CLK_8192FS },
+};
+
+/**
+ * get_dim2_clk_speed - converts string to DIM2 clock speed value
+ *
+ * @clock_speed: string in the format "{NUMBER}fs"
+ * @val: pointer to get one of the CLK_{NUMBER}FS values
+ *
+ * By success stores one of the CLK_{NUMBER}FS in the *val and returns 0,
+ * otherwise returns -EINVAL.
+ */
+static int get_dim2_clk_speed(const char *clock_speed, u8 *val)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(clk_mt); i++) {
+ if (!strcmp(clock_speed, clk_mt[i].clock_speed)) {
+ *val = clk_mt[i].clk_speed;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
/*
* dim2_probe - dim2 probe handler
* @pdev: platform device structure
@@ -708,6 +744,7 @@ static const struct of_device_id dim2_of_match[];
static int dim2_probe(struct platform_device *pdev)
{
const struct dim2_platform_data *pdata;
+ const char *clock_speed;
struct dim2_hdm *dev;
struct resource *res;
int ret, i;
@@ -725,7 +762,18 @@ static int dim2_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, dev);
- dev->clk_speed = CLK_4096FS;
+ ret = of_property_read_string(pdev->dev.of_node,
+ "microchip,clock-speed", &clock_speed);
+ if (ret) {
+ dev_err(&pdev->dev, "missing dt property clock-speed\n");
+ return ret;
+ }
+
+ ret = get_dim2_clk_speed(clock_speed, &dev->clk_speed);
+ if (ret) {
+ dev_err(&pdev->dev, "bad dt property clock-speed\n");
+ return ret;
+ }
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
dev->io_base = devm_ioremap_resource(&pdev->dev, res);
--
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