[PATCH v6] ARM: davinci: i2c: add OF support
Heiko Schocher
hs at denx.de
Tue Jul 17 04:40:47 EDT 2012
add of support for the davinci i2c driver.
Signed-off-by: Heiko Schocher <hs at denx.de>
Signed-off-by: Sekhar Nori <nsekhar at ti.com>
Cc: davinci-linux-open-source at linux.davincidsp.com
Cc: linux-arm-kernel at lists.infradead.org
Cc: devicetree-discuss at lists.ozlabs.org
Cc: linux-i2c at vger.kernel.org
Cc: Ben Dooks <ben-linux at fluff.org>
Cc: Wolfram Sang <w.sang at pengutronix.de>
Cc: Grant Likely <grant.likely at secretlab.ca>
Cc: Sekhar Nori <nsekhar at ti.com>
Cc: Wolfgang Denk <wd at denx.de>
Cc: Sylwester Nawrocki <s.nawrocki at samsung.com>
---
- changes for v2:
- add comments from Sylwester Nawrocki <s.nawrocki at samsung.com>:
- use "cell-index" instead "id"
- OF_DEV_AUXDATA in the machine code, instead pre-define platform
device name
- add comment from Grant Likely:
- removed "id" resp. "cell-index" completely
- fixed documentation
- use of_match_ptr()
- use devm_kzalloc() for allocating plattform data mem
- fixed a whitespace issue
- no changes for v3
- changes for v4
remove "pinmux-handle" property as discussed here:
http://www.spinics.net/lists/arm-kernel/msg175701.html
with Nori Sekhar
- changes for v5
add comments from Grant Likely:
- do not change value of dev->dev->platform_data, instead
hold a copy in davinci_i2c_dev.
- changes for v6:
add comments from Sekhar Nori:
- removed unneccessary include
- merge patch from Sekhar Nori:
setup the newly introduced dev->pdata member correctly once in
probe -> i2c_get_plattformdata(() not needed, remove a lot of
checks for pdata in code
- add Signed-off-by: Sekhar Nori <nsekhar at ti.com>
- patch no longer in patchserie, as it has no dependencies.
---
.../devicetree/bindings/arm/davinci/i2c.txt | 31 ++++++++++++
drivers/i2c/busses/i2c-davinci.c | 50 +++++++++++++++----
2 files changed, 70 insertions(+), 11 deletions(-)
create mode 100644 Documentation/devicetree/bindings/arm/davinci/i2c.txt
diff --git a/Documentation/devicetree/bindings/arm/davinci/i2c.txt b/Documentation/devicetree/bindings/arm/davinci/i2c.txt
new file mode 100644
index 0000000..e98a025
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/davinci/i2c.txt
@@ -0,0 +1,31 @@
+* 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 : <a> standard interrupt property.
+- clock-frequency : desired I2C bus clock frequency in Hz.
+
+Optional properties:
+- bus-delay: bus delay in usec
+
+Example (enbw_cmc board):
+ i2c at 1c22000 {
+ compatible = "ti,davinci-i2c";
+ reg = <0x22000 0x1000>;
+ clock-frequency = <100000>;
+ interrupts = <15>;
+ interrupt-parent = <&intc>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ dtt at 48 {
+ compatible = "national,lm75";
+ reg = <0x48>;
+ };
+ };
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index a76d85f..8d4efce 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -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>
@@ -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 */
@@ -155,7 +158,7 @@ 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 */
@@ -163,8 +166,7 @@ static void i2c_recover_bus(struct davinci_i2c_dev *dev)
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;
@@ -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;
@@ -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);
@@ -308,13 +307,11 @@ 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);
@@ -635,6 +632,12 @@ 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;
@@ -674,8 +677,30 @@ 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;
+ if (!of_property_read_u32(pdev->dev.of_node, "bus-delay",
+ &prop))
+ dev->pdata->bus_delay = prop;
+ } 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;
@@ -711,6 +736,7 @@ 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);
@@ -718,6 +744,7 @@ static int davinci_i2c_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "failure adding adapter\n");
goto err_free_irq;
}
+ of_i2c_register_devices(adap);
return 0;
@@ -809,6 +836,7 @@ 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),
},
};
--
1.7.7.6
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