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Subject[PATCH 1/3] i2c: Add Device Tree support to the Nomadik I2C driver
From: Lee Jones <lee.jones@linaro.org>
Date: Tue, 17 Apr 2012 16:04:13 +0100
Subject: [PATCH 1/3] i2c: Add Device Tree support to the Nomadik I2C driver

Here we apply the bindings required for successful Device Tree
probing of the i2c-nomadik driver. We also apply a fall-back
configuration in case either one is not provided, or a required
element is missing from the one supplied.

Cc: linux-i2c@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
---
drivers/i2c/busses/i2c-nomadik.c | 92 ++++++++++++++++++++++++++++++++++----
1 file changed, 84 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index a92440d..b97f52e 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -23,6 +23,7 @@
#include <linux/io.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
+#include <linux/of.h>

#include <plat/i2c.h>

@@ -899,15 +900,86 @@ static const struct i2c_algorithm nmk_i2c_algo = {
.functionality = nmk_i2c_functionality
};

+static struct nmk_i2c_controller u8500_i2c = {
+ /*
+ * Slave data setup time; 250ns, 100ns, and 10ns, which
+ * is 14, 6 and 2 respectively for a 48Mhz i2c clock.
+ */
+ .slsu = 0xe,
+ .tft = 1, /* Tx FIFO threshold */
+ .rft = 8, /* Rx FIFO threshold */
+ .clk_freq = 100000, /* std. mode operation */
+ .timeout = 200, /* Slave response timeout(ms) */
+ .sm = I2C_FREQ_MODE_FAST,
+};
+
+static int __devinit
+nmk_i2c_of_probe(struct device_node *np, struct nmk_i2c_controller *pdata)
+{
+ of_property_read_u32(np, "clock-frequency", (u32*)&pdata->clk_freq);
+ if (!pdata->clk_freq) {
+ pr_warn("%s: Clock frequency not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,slsu", (u32*)&pdata->slsu);
+ if (!pdata->slsu) {
+ pr_warn("%s: Data line delay not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,tft", (u32*)&pdata->tft);
+ if (!pdata->tft) {
+ pr_warn("%s: Tx FIFO threshold not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,rft", (u32*)&pdata->rft);
+ if (!pdata->rft) {
+ pr_warn("%s: Rx FIFO threshold not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ of_property_read_u32(np, "stericsson,timeout", (u32*)&pdata->timeout);
+ if (!pdata->timeout) {
+ pr_warn("%s: Timeout not found\n", np->full_name);
+ return -EINVAL;
+ }
+
+ if (of_get_property(np, "stericsson,i2c_freq_mode_fast", NULL))
+ pdata->sm = I2C_FREQ_MODE_FAST;
+ else
+ pdata->sm = I2C_FREQ_MODE_STANDARD;
+
+ return 0;
+}
+
static int __devinit nmk_i2c_probe(struct platform_device *pdev)
{
int ret = 0;
struct resource *res;
- struct nmk_i2c_controller *pdata =
- pdev->dev.platform_data;
+ struct nmk_i2c_controller *pdata = pdev->dev.platform_data;
+ struct device_node *np = pdev->dev.of_node;
struct nmk_i2c_dev *dev;
struct i2c_adapter *adap;

+ if (np) {
+ if (!pdata) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ ret = -ENOMEM;
+ goto err_no_mem;
+ }
+ }
+ ret = nmk_i2c_of_probe(np, pdata);
+ if (ret)
+ kfree(pdata);
+ }
+
+ if (!pdata)
+ /* No i2c configuration found, using the default. */
+ pdata = &u8500_i2c;
+
dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
if (!dev) {
dev_err(&pdev->dev, "cannot allocate memory\n");
@@ -974,12 +1046,10 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)

/* fetch the controller configuration from machine */
dev->cfg.clk_freq = pdata->clk_freq;
- dev->cfg.slsu = pdata->slsu;
- dev->cfg.tft = pdata->tft;
- dev->cfg.rft = pdata->rft;
- dev->cfg.sm = pdata->sm;
-
- i2c_set_adapdata(adap, dev);
+ dev->cfg.slsu = pdata->slsu;
+ dev->cfg.tft = pdata->tft;
+ dev->cfg.rft = pdata->rft;
+ dev->cfg.sm = pdata->sm; i2c_set_adapdata(adap, dev);

dev_info(&pdev->dev,
"initialize %s on virtual base %p\n",
@@ -1038,11 +1108,17 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev)
return 0;
}

+static const struct of_device_id nmk_gpio_match[] = {
+ { .compatible = "st,nomadik-i2c", },
+ {},
+};
+
static struct platform_driver nmk_i2c_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRIVER_NAME,
.pm = &nmk_i2c_pm,
+ .of_match_table = nmk_gpio_match,
},
.probe = nmk_i2c_probe,
.remove = __devexit_p(nmk_i2c_remove),
--
1.7.9.5

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