From 09af1c2fa490169c40cbd153c5b83b5a70a0ec4b Mon Sep 17 00:00:00 2001
From: Heiner Kallweit <hkallweit1@gmail.com>
Date: Sat, 25 Mar 2017 14:04:42 +0100
Subject: [PATCH] i2c: meson: set clock divider in probe instead of setting it
for each transfer
The bus frequency is fixed to what is set DT, therefore we can set
the clock divider in probe already and we don't have to set it for
each transfer.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
---
drivers/i2c/busses/i2c-meson.c | 17 ++++++++---------
1 file changed, 8 insertions(+), 9 deletions(-)
diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c
index 04614a6010d60..a692594fb82c5 100644
--- a/drivers/i2c/busses/i2c-meson.c
+++ b/drivers/i2c/busses/i2c-meson.c
@@ -73,7 +73,6 @@ enum {
* @error: Flag set when an error is received
* @lock: To avoid race conditions between irq handler and xfer code
* @done: Completion used to wait for transfer termination
- * @frequency: Operating frequency of I2C bus clock
* @tokens: Sequence of tokens to be written to the device
* @num_tokens: Number of tokens
*/
@@ -92,7 +91,6 @@ struct meson_i2c {
spinlock_t lock;
struct completion done;
- unsigned int frequency;
u32 tokens[2];
int num_tokens;
};
@@ -131,17 +129,17 @@ static void meson_i2c_write_tokens(struct meson_i2c *i2c)
writel(i2c->tokens[1], i2c->regs + REG_TOK_LIST1);
}
-static void meson_i2c_set_clk_div(struct meson_i2c *i2c)
+static void meson_i2c_set_clk_div(struct meson_i2c *i2c, unsigned int freq)
{
unsigned long clk_rate = clk_get_rate(i2c->clk);
unsigned int div;
- div = DIV_ROUND_UP(clk_rate, i2c->frequency * 4);
+ div = DIV_ROUND_UP(clk_rate, freq * 4);
meson_i2c_set_mask(i2c, REG_CTRL, REG_CTRL_CLKDIV_MASK,
div << REG_CTRL_CLKDIV_SHIFT);
dev_dbg(i2c->dev, "%s: clk %lu, freq %u, div %u\n", __func__,
- clk_rate, i2c->frequency, div);
+ clk_rate, freq, div);
}
static void meson_i2c_get_data(struct meson_i2c *i2c, char *buf, int len)
@@ -361,7 +359,6 @@ static int meson_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
int i, ret = 0, count = 0;
clk_enable(i2c->clk);
- meson_i2c_set_clk_div(i2c);
for (i = 0; i < num; i++) {
ret = meson_i2c_xfer_msg(i2c, msgs + i, i == num - 1);
@@ -390,15 +387,15 @@ static int meson_i2c_probe(struct platform_device *pdev)
struct device_node *np = pdev->dev.of_node;
struct meson_i2c *i2c;
struct resource *mem;
+ u32 freq;
int irq, ret = 0;
i2c = devm_kzalloc(&pdev->dev, sizeof(struct meson_i2c), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
- if (of_property_read_u32(pdev->dev.of_node, "clock-frequency",
- &i2c->frequency))
- i2c->frequency = DEFAULT_FREQ;
+ if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", &freq))
+ freq = DEFAULT_FREQ;
i2c->dev = &pdev->dev;
platform_set_drvdata(pdev, i2c);
@@ -455,6 +452,8 @@ static int meson_i2c_probe(struct platform_device *pdev)
return ret;
}
+ meson_i2c_set_clk_div(i2c, freq);
+
return 0;
}
--
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