On Mon, Jan 23, 2012 at 09:56:05AM +0100, Heiko Schocher wrote:
> add of support for the davinci i2c driver.
>
> Signed-off-by: Heiko Schocher <hs@xxxxxxx>
> Cc: davinci-linux-open-source@xxxxxxxxxxxxxxxxxxxx
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: devicetree-discuss@xxxxxxxxxxxxxxxx
> Cc: linux-i2c@xxxxxxxxxxxxxxx
> Cc: Ben Dooks <ben-linux@xxxxxxxxx>
> Cc: Wolfram Sang <w.sang@xxxxxxxxxxxxxx>
> Cc: Grant Likely <grant.likely@xxxxxxxxxxxx>
> Cc: Sekhar Nori <nsekhar@xxxxxx>
> Cc: Wolfgang Denk <wd@xxxxxxx>
Hi Heiko,
comments below.
> ---
> .../devicetree/bindings/arm/davinci/i2c.txt | 39 ++++++++++++++++++
> drivers/i2c/busses/i2c-davinci.c | 43 ++++++++++++++++++++
> 2 files changed, 82 insertions(+), 0 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..94ec670
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/arm/davinci/i2c.txt
> @@ -0,0 +1,39 @@
> +* 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
> +- id: id of the controller
Don't use an 'id' property. i2c bus numbers should be dynamically
assigned when using the device tree.
> +
> +Recommended properties :
> +- interrupts : <a b> where a is the interrupt number and b is a
> + field that represents an encoding of the sense and level
> + information for the interrupt.
This is inaccurate. It is entirely defined by the interrupt
controller. All you need to say here is that this is a standard
interrupts property.
> +- interrupt-parent : the phandle for the interrupt controller that
> + services interrupts for this device.
Don't even mention this one. It can often be inherited from a parent
node.
> +- clock-frequency : desired I2C bus clock frequency in Hz.
> +
> +Optional properties:
> +- bus-delay: bus delay in usec
> +- pinmux-handle: Contains a handle to configure the pinmux settings.
> +
> +Example (enbw_cmc board):
> + i2c@1c22000 {
> + compatible = "ti,davinci-i2c";
> + reg = <0x22000 0x1000>;
> + clock-frequency = <100000>;
> + interrupts = <15 2>;
> + interrupt-parent = <&intc>;
> + id = <1>;
> + pinmux-handle = <&i2c1_pins>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + dtt@48 {
> + compatible = "national,lm75";
> + reg = <0x48>;
> + };
> + };
> diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
> index a76d85f..6f59fae 100644
> --- a/drivers/i2c/busses/i2c-davinci.c
> +++ b/drivers/i2c/busses/i2c-davinci.c
> @@ -38,9 +38,12 @@
> #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>
> +#include <mach/mux.h>
>
> /* ----- global defines ----------------------------------------------- */
>
> @@ -635,6 +638,16 @@ static struct i2c_algorithm i2c_davinci_algo = {
> .functionality = i2c_davinci_func,
> };
>
> +#if defined(CONFIG_OF)
> +static const struct of_device_id davinci_i2c_of_match[] = {
> + {.compatible = "ti,davinci-i2c", },
> + {},
> +}
> +MODULE_DEVICE_TABLE(of, davinci_i2c_of_match);
> +#else
> +#define davinci_i2c_of_match NULL
> +#endif
The #else clause can be dropped if you use the of_match_ptr() macro
when referencing it.
> +
> static int davinci_i2c_probe(struct platform_device *pdev)
> {
> struct davinci_i2c_dev *dev;
> @@ -676,7 +689,34 @@ static int davinci_i2c_probe(struct platform_device *pdev)
> dev->irq = irq->start;
> platform_set_drvdata(pdev, dev);
>
> + if ((dev->dev->platform_data == NULL) &&
> + (pdev->dev.of_node)) {
> + struct device_node *pinmux_np;
> + struct davinci_i2c_platform_data *pdata;
> + u32 prop;
> +
> + dev->dev->platform_data = &davinci_i2c_platform_data_default;
Don't do this. What if a davinci part shows up with two i2c busses?
Use devm_kzalloc() instead.
> + pdata = &davinci_i2c_platform_data_default;
> + if (!of_property_read_u32(pdev->dev.of_node, "clock-frequency",
> + &prop))
> + pdata->bus_freq = prop / 1000;
> + if (!of_property_read_u32(pdev->dev.of_node, "bus-delay",
> + &prop))
> + pdata->bus_delay = prop;
> + if (!of_property_read_u32(pdev->dev.of_node, "id",
> + &prop)) {
> + pdev->id = prop;
> + pdev->dev.init_name = kzalloc(20, GFP_KERNEL);
> + sprintf((char *)pdev->dev.init_name,
> + "i2c_davinci.%d", pdev->id);
Blech! Drop this. Leave the core code to set the device name.
> dev->clk = clk_get(&pdev->dev, NULL);
> +
> if (IS_ERR(dev->clk)) {
Nit: unrelated whitespace change
> r = -ENODEV;
> goto err_free_mem;
> @@ -711,6 +751,7 @@ 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 +759,7 @@ 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 +851,7 @@ static struct platform_driver davinci_i2c_driver = {
> .name = "i2c_davinci",
> .owner = THIS_MODULE,
> .pm = davinci_i2c_pm_ops,
> + .of_match_table = davinci_i2c_of_match,
> },
> };
>
> --
> 1.7.7.5
>
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