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r: 333364
b: refs/heads/master
c: 5c3d8a4
h: refs/heads/master
v: v3
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Heiko Schocher authored and Wolfram Sang committed Sep 12, 2012
1 parent 6bf659a commit 70caee0
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Showing 3 changed files with 66 additions and 12 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 002f002d956e6b01700ab8753c6f268c9aafc34a
refs/heads/master: 5c3d8a46ac9778d117ca26f4fec18d7b8c8831ed
28 changes: 28 additions & 0 deletions trunk/Documentation/devicetree/bindings/i2c/davinci.txt
Original file line number Diff line number Diff line change
@@ -0,0 +1,28 @@
* Texas Instruments Davinci I2C

This file provides information, what the device node for the
davinci i2c interface contain.

Required properties:
- compatible: "ti,davinci-i2c";
- reg : Offset and length of the register set for the device

Recommended properties :
- interrupts : standard interrupt property.
- clock-frequency : desired I2C bus clock frequency in Hz.

Example (enbw_cmc board):
i2c@1c22000 {
compatible = "ti,davinci-i2c";
reg = <0x22000 0x1000>;
clock-frequency = <100000>;
interrupts = <15>;
interrupt-parent = <&intc>;
#address-cells = <1>;
#size-cells = <0>;

dtt@48 {
compatible = "national,lm75";
reg = <0x48>;
};
};
48 changes: 37 additions & 11 deletions trunk/drivers/i2c/busses/i2c-davinci.c
Original file line number Diff line number Diff line change
Expand Up @@ -38,6 +38,8 @@
#include <linux/slab.h>
#include <linux/cpufreq.h>
#include <linux/gpio.h>
#include <linux/of_i2c.h>
#include <linux/of_device.h>

#include <mach/hardware.h>
#include <mach/i2c.h>
Expand Down Expand Up @@ -114,6 +116,7 @@ struct davinci_i2c_dev {
struct completion xfr_complete;
struct notifier_block freq_transition;
#endif
struct davinci_i2c_platform_data *pdata;
};

/* default platform data to use if not supplied in the platform_device */
Expand Down Expand Up @@ -155,16 +158,15 @@ static void generic_i2c_clock_pulse(unsigned int scl_pin)
static void i2c_recover_bus(struct davinci_i2c_dev *dev)
{
u32 flag = 0;
struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
struct davinci_i2c_platform_data *pdata = dev->pdata;

dev_err(dev->dev, "initiating i2c bus recovery\n");
/* Send NACK to the slave */
flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
flag |= DAVINCI_I2C_MDR_NACK;
/* write the data into mode register */
davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);
if (pdata)
generic_i2c_clock_pulse(pdata->scl_pin);
generic_i2c_clock_pulse(pdata->scl_pin);
/* Send STOP */
flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_MDR_REG);
flag |= DAVINCI_I2C_MDR_STP;
Expand All @@ -187,7 +189,7 @@ static inline void davinci_i2c_reset_ctrl(struct davinci_i2c_dev *i2c_dev,

static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
{
struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
struct davinci_i2c_platform_data *pdata = dev->pdata;
u16 psc;
u32 clk;
u32 d;
Expand Down Expand Up @@ -235,10 +237,7 @@ static void i2c_davinci_calc_clk_dividers(struct davinci_i2c_dev *dev)
*/
static int i2c_davinci_init(struct davinci_i2c_dev *dev)
{
struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;

if (!pdata)
pdata = &davinci_i2c_platform_data_default;
struct davinci_i2c_platform_data *pdata = dev->pdata;

/* put I2C into reset */
davinci_i2c_reset_ctrl(dev, 0);
Expand All @@ -260,6 +259,7 @@ static int i2c_davinci_init(struct davinci_i2c_dev *dev)
dev_dbg(dev->dev, "bus_freq = %dkHz, bus_delay = %d\n",
pdata->bus_freq, pdata->bus_delay);


/* Take the I2C module out of reset: */
davinci_i2c_reset_ctrl(dev, 1);

Expand Down Expand Up @@ -308,13 +308,11 @@ static int
i2c_davinci_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, int stop)
{
struct davinci_i2c_dev *dev = i2c_get_adapdata(adap);
struct davinci_i2c_platform_data *pdata = dev->dev->platform_data;
struct davinci_i2c_platform_data *pdata = dev->pdata;
u32 flag;
u16 w;
int r;

if (!pdata)
pdata = &davinci_i2c_platform_data_default;
/* Introduce a delay, required for some boards (e.g Davinci EVM) */
if (pdata->bus_delay)
udelay(pdata->bus_delay);
Expand Down Expand Up @@ -635,6 +633,12 @@ static struct i2c_algorithm i2c_davinci_algo = {
.functionality = i2c_davinci_func,
};

static const struct of_device_id davinci_i2c_of_match[] = {
{.compatible = "ti,davinci-i2c", },
{},
};
MODULE_DEVICE_TABLE(of, davinci_i2c_of_match);

static int davinci_i2c_probe(struct platform_device *pdev)
{
struct davinci_i2c_dev *dev;
Expand Down Expand Up @@ -674,8 +678,27 @@ static int davinci_i2c_probe(struct platform_device *pdev)
#endif
dev->dev = get_device(&pdev->dev);
dev->irq = irq->start;
dev->pdata = dev->dev->platform_data;
platform_set_drvdata(pdev, dev);

if (!dev->pdata && pdev->dev.of_node) {
u32 prop;

dev->pdata = devm_kzalloc(&pdev->dev,
sizeof(struct davinci_i2c_platform_data), GFP_KERNEL);
if (!dev->pdata) {
r = -ENOMEM;
goto err_free_mem;
}
memcpy(dev->pdata, &davinci_i2c_platform_data_default,
sizeof(struct davinci_i2c_platform_data));
if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
&prop))
dev->pdata->bus_freq = prop / 1000;
} else if (!dev->pdata) {
dev->pdata = &davinci_i2c_platform_data_default;
}

dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk)) {
r = -ENODEV;
Expand Down Expand Up @@ -711,13 +734,15 @@ static int davinci_i2c_probe(struct platform_device *pdev)
adap->algo = &i2c_davinci_algo;
adap->dev.parent = &pdev->dev;
adap->timeout = DAVINCI_I2C_TIMEOUT;
adap->dev.of_node = pdev->dev.of_node;

adap->nr = pdev->id;
r = i2c_add_numbered_adapter(adap);
if (r) {
dev_err(&pdev->dev, "failure adding adapter\n");
goto err_free_irq;
}
of_i2c_register_devices(adap);

return 0;

Expand Down Expand Up @@ -809,6 +834,7 @@ static struct platform_driver davinci_i2c_driver = {
.name = "i2c_davinci",
.owner = THIS_MODULE,
.pm = davinci_i2c_pm_ops,
.of_match_table = of_match_ptr(davinci_i2c_of_match),
},
};

Expand Down

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