[PATCH v7] ARM: davinci: i2c: add OF support

[Shubhrajyoti Datta]

On Mon, Jul 30, 2012 at 12:51 PM, Heiko Schocher <hs at denx.de> wrote:
> 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.
>
> - changes for v7:
>   add comments from Wolfram Sang:
>   - move Documentation/devicetree/bindings/arm/davinci/i2c.txt
>     to Documentation/devicetree/bindings/i2c/davinci.txt
>   - remove bus-delay property
>
>  Documentation/devicetree/bindings/i2c/davinci.txt |   28 ++++++++++++
>  drivers/i2c/busses/i2c-davinci.c                  |   48 ++++++++++++++++-----
>  2 files changed, 65 insertions(+), 11 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/i2c/davinci.txt
>
> diff --git a/Documentation/devicetree/bindings/i2c/davinci.txt b/Documentation/devicetree/bindings/i2c/davinci.txt
> new file mode 100644
> index 0000000..c79078e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/davinci.txt
> @@ -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 : <a> standard interrupt property.
> +- clock-frequency : desired I2C bus clock frequency in Hz.
> +
> +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 79b4bcb..b6185dc 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);
> @@ -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);
>
> @@ -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);
> @@ -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);
> +

Should this be protected under OF flag?