[PATCH 2/5] i2c: meson: add configurable divider factors

From: Yixun Lan
Date: Fri Nov 17 2017 - 03:03:56 EST


From: Jian Hu <jian.hu@xxxxxxxxxxx>

This patch try to add support for I2C controller in Meson-AXG SoC,
Due to the IP changes between I2C controller, we need to introduce
a compatible data to make the divider factor configurable.

Signed-off-by: Jian Hu <jian.hu@xxxxxxxxxxx>
Signed-off-by: Yixun Lan <yixun.lan@xxxxxxxxxxx>
---
drivers/i2c/busses/i2c-meson.c | 32 ++++++++++++++++++++++++++++----
1 file changed, 28 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-meson.c b/drivers/i2c/busses/i2c-meson.c
index 88d15b92ec35..517f2cddeff3 100644
--- a/drivers/i2c/busses/i2c-meson.c
+++ b/drivers/i2c/busses/i2c-meson.c
@@ -16,6 +16,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/types.h>

@@ -57,6 +58,10 @@ enum {
STATE_WRITE,
};

+struct meson_i2c_data {
+ unsigned char div_factor;
+};
+
/**
* struct meson_i2c - Meson I2C device private data
*
@@ -93,6 +98,8 @@ struct meson_i2c {
struct completion done;
u32 tokens[2];
int num_tokens;
+
+ struct meson_i2c_data *data;
};

static void meson_i2c_set_mask(struct meson_i2c *i2c, int reg, u32 mask,
@@ -128,7 +135,7 @@ 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, freq * 4);
+ div = DIV_ROUND_UP(clk_rate, freq * i2c->data->div_factor);

/* clock divider has 12 bits */
if (div >= (1 << 12)) {
@@ -376,6 +383,9 @@ static int meson_i2c_probe(struct platform_device *pdev)
spin_lock_init(&i2c->lock);
init_completion(&i2c->done);

+ i2c->data = (struct meson_i2c_data *)
+ of_device_get_match_data(&pdev->dev);
+
i2c->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(i2c->clk)) {
dev_err(&pdev->dev, "can't get device clock\n");
@@ -440,11 +450,25 @@ static int meson_i2c_remove(struct platform_device *pdev)
return 0;
}

+static const struct meson_i2c_data i2c_meson6_data = {
+ .div_factor = 4,
+};
+
+static const struct meson_i2c_data i2c_gxbb_data = {
+ .div_factor = 4,
+};
+
+static const struct meson_i2c_data i2c_axg_data = {
+ .div_factor = 3,
+};
+
static const struct of_device_id meson_i2c_match[] = {
- { .compatible = "amlogic,meson6-i2c" },
- { .compatible = "amlogic,meson-gxbb-i2c" },
- { },
+ { .compatible = "amlogic,meson6-i2c", .data = &i2c_meson6_data },
+ { .compatible = "amlogic,meson-gxbb-i2c", .data = &i2c_gxbb_data },
+ { .compatible = "amlogic,meson-axg-i2c", .data = &i2c_axg_data },
+ {},
};
+
MODULE_DEVICE_TABLE(of, meson_i2c_match);

static struct platform_driver meson_i2c_driver = {
--
2.14.1