summaryrefslogtreecommitdiffstats
path: root/drivers/i2c
diff options
context:
space:
mode:
authorJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>2012-02-05 18:22:34 +0800
committerJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>2012-03-15 23:29:22 +0800
commit8ffaa0f40db22564efc44588a9d861d78a1fae02 (patch)
tree4c255465cc79e8ec7cc36812add87b64ee06e07d /drivers/i2c
parent86a89f4ff665d385741a7831c612fc0b9aa22480 (diff)
downloadlinux-8ffaa0f40db22564efc44588a9d861d78a1fae02.tar.bz2
i2c/gpio: add DT support
To achieve DT support, we need to populate a custom platform_data in a private struct from DT information. To simplify code, the adapter and algorithm are also put into the private struct. Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Rob Herring <rob.herring@calxeda.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-gpio.c98
1 files changed, 76 insertions, 22 deletions
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index a651779d9ff7..c0330a41db03 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -14,8 +14,15 @@
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
-
-#include <asm/gpio.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/of_i2c.h>
+
+struct i2c_gpio_private_data {
+ struct i2c_adapter adap;
+ struct i2c_algo_bit_data bit_data;
+ struct i2c_gpio_platform_data pdata;
+};
/* Toggle SDA by changing the direction of the pin */
static void i2c_gpio_setsda_dir(void *data, int state)
@@ -78,24 +85,62 @@ static int i2c_gpio_getscl(void *data)
return gpio_get_value(pdata->scl_pin);
}
+static int __devinit of_i2c_gpio_probe(struct device_node *np,
+ struct i2c_gpio_platform_data *pdata)
+{
+ u32 reg;
+
+ if (of_gpio_count(np) < 2)
+ return -ENODEV;
+
+ pdata->sda_pin = of_get_gpio(np, 0);
+ pdata->scl_pin = of_get_gpio(np, 1);
+
+ if (!gpio_is_valid(pdata->sda_pin) || !gpio_is_valid(pdata->scl_pin)) {
+ pr_err("%s: invalid GPIO pins, sda=%d/scl=%d\n",
+ np->full_name, pdata->sda_pin, pdata->scl_pin);
+ return -ENODEV;
+ }
+
+ of_property_read_u32(np, "i2c-gpio,delay-us", &pdata->udelay);
+
+ if (!of_property_read_u32(np, "i2c-gpio,timeout-ms", &reg))
+ pdata->timeout = msecs_to_jiffies(reg);
+
+ pdata->sda_is_open_drain =
+ of_property_read_bool(np, "i2c-gpio,sda-open-drain");
+ pdata->scl_is_open_drain =
+ of_property_read_bool(np, "i2c-gpio,scl-open-drain");
+ pdata->scl_is_output_only =
+ of_property_read_bool(np, "i2c-gpio,scl-output-only");
+
+ return 0;
+}
+
static int __devinit i2c_gpio_probe(struct platform_device *pdev)
{
+ struct i2c_gpio_private_data *priv;
struct i2c_gpio_platform_data *pdata;
struct i2c_algo_bit_data *bit_data;
struct i2c_adapter *adap;
int ret;
- pdata = pdev->dev.platform_data;
- if (!pdata)
- return -ENXIO;
-
- ret = -ENOMEM;
- adap = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
- if (!adap)
- goto err_alloc_adap;
- bit_data = kzalloc(sizeof(struct i2c_algo_bit_data), GFP_KERNEL);
- if (!bit_data)
- goto err_alloc_bit_data;
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ adap = &priv->adap;
+ bit_data = &priv->bit_data;
+ pdata = &priv->pdata;
+
+ if (pdev->dev.of_node) {
+ ret = of_i2c_gpio_probe(pdev->dev.of_node, pdata);
+ if (ret)
+ return ret;
+ } else {
+ if (!pdev->dev.platform_data)
+ return -ENXIO;
+ memcpy(pdata, pdev->dev.platform_data, sizeof(*pdata));
+ }
ret = gpio_request(pdata->sda_pin, "sda");
if (ret)
@@ -143,6 +188,7 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev)
adap->algo_data = bit_data;
adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
adap->dev.parent = &pdev->dev;
+ adap->dev.of_node = pdev->dev.of_node;
/*
* If "dev->id" is negative we consider it as zero.
@@ -154,7 +200,9 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev)
if (ret)
goto err_add_bus;
- platform_set_drvdata(pdev, adap);
+ of_i2c_register_devices(adap);
+
+ platform_set_drvdata(pdev, priv);
dev_info(&pdev->dev, "using pins %u (SDA) and %u (SCL%s)\n",
pdata->sda_pin, pdata->scl_pin,
@@ -168,34 +216,40 @@ err_add_bus:
err_request_scl:
gpio_free(pdata->sda_pin);
err_request_sda:
- kfree(bit_data);
-err_alloc_bit_data:
- kfree(adap);
-err_alloc_adap:
return ret;
}
static int __devexit i2c_gpio_remove(struct platform_device *pdev)
{
+ struct i2c_gpio_private_data *priv;
struct i2c_gpio_platform_data *pdata;
struct i2c_adapter *adap;
- adap = platform_get_drvdata(pdev);
- pdata = pdev->dev.platform_data;
+ priv = platform_get_drvdata(pdev);
+ adap = &priv->adap;
+ pdata = &priv->pdata;
i2c_del_adapter(adap);
gpio_free(pdata->scl_pin);
gpio_free(pdata->sda_pin);
- kfree(adap->algo_data);
- kfree(adap);
return 0;
}
+#if defined(CONFIG_OF)
+static const struct of_device_id i2c_gpio_dt_ids[] = {
+ { .compatible = "i2c-gpio", },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, i2c_gpio_dt_ids);
+#endif
+
static struct platform_driver i2c_gpio_driver = {
.driver = {
.name = "i2c-gpio",
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(i2c_gpio_dt_ids),
},
.probe = i2c_gpio_probe,
.remove = __devexit_p(i2c_gpio_remove),