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    Subject[PATCH 1/3] i2c: Add Device Tree support to the Nomadik I2C driver
    From: Lee Jones <lee.jones@linaro.org>
    Date: Tue, 17 Apr 2012 16:04:13 +0100
    Subject: [PATCH 1/3] i2c: Add Device Tree support to the Nomadik I2C driver

    Here we apply the bindings required for successful Device Tree
    probing of the i2c-nomadik driver. We also apply a fall-back
    configuration in case either one is not provided, or a required
    element is missing from the one supplied.

    Cc: linux-i2c@vger.kernel.org
    Signed-off-by: Lee Jones <lee.jones@linaro.org>
    ---
    drivers/i2c/busses/i2c-nomadik.c | 92 ++++++++++++++++++++++++++++++++++----
    1 file changed, 84 insertions(+), 8 deletions(-)

    diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
    index a92440d..b97f52e 100644
    --- a/drivers/i2c/busses/i2c-nomadik.c
    +++ b/drivers/i2c/busses/i2c-nomadik.c
    @@ -23,6 +23,7 @@
    #include <linux/io.h>
    #include <linux/regulator/consumer.h>
    #include <linux/pm_runtime.h>
    +#include <linux/of.h>

    #include <plat/i2c.h>

    @@ -899,15 +900,86 @@ static const struct i2c_algorithm nmk_i2c_algo = {
    .functionality = nmk_i2c_functionality
    };

    +static struct nmk_i2c_controller u8500_i2c = {
    + /*
    + * Slave data setup time; 250ns, 100ns, and 10ns, which
    + * is 14, 6 and 2 respectively for a 48Mhz i2c clock.
    + */
    + .slsu = 0xe,
    + .tft = 1, /* Tx FIFO threshold */
    + .rft = 8, /* Rx FIFO threshold */
    + .clk_freq = 100000, /* std. mode operation */
    + .timeout = 200, /* Slave response timeout(ms) */
    + .sm = I2C_FREQ_MODE_FAST,
    +};
    +
    +static int __devinit
    +nmk_i2c_of_probe(struct device_node *np, struct nmk_i2c_controller *pdata)
    +{
    + of_property_read_u32(np, "clock-frequency", (u32*)&pdata->clk_freq);
    + if (!pdata->clk_freq) {
    + pr_warn("%s: Clock frequency not found\n", np->full_name);
    + return -EINVAL;
    + }
    +
    + of_property_read_u32(np, "stericsson,slsu", (u32*)&pdata->slsu);
    + if (!pdata->slsu) {
    + pr_warn("%s: Data line delay not found\n", np->full_name);
    + return -EINVAL;
    + }
    +
    + of_property_read_u32(np, "stericsson,tft", (u32*)&pdata->tft);
    + if (!pdata->tft) {
    + pr_warn("%s: Tx FIFO threshold not found\n", np->full_name);
    + return -EINVAL;
    + }
    +
    + of_property_read_u32(np, "stericsson,rft", (u32*)&pdata->rft);
    + if (!pdata->rft) {
    + pr_warn("%s: Rx FIFO threshold not found\n", np->full_name);
    + return -EINVAL;
    + }
    +
    + of_property_read_u32(np, "stericsson,timeout", (u32*)&pdata->timeout);
    + if (!pdata->timeout) {
    + pr_warn("%s: Timeout not found\n", np->full_name);
    + return -EINVAL;
    + }
    +
    + if (of_get_property(np, "stericsson,i2c_freq_mode_fast", NULL))
    + pdata->sm = I2C_FREQ_MODE_FAST;
    + else
    + pdata->sm = I2C_FREQ_MODE_STANDARD;
    +
    + return 0;
    +}
    +
    static int __devinit nmk_i2c_probe(struct platform_device *pdev)
    {
    int ret = 0;
    struct resource *res;
    - struct nmk_i2c_controller *pdata =
    - pdev->dev.platform_data;
    + struct nmk_i2c_controller *pdata = pdev->dev.platform_data;
    + struct device_node *np = pdev->dev.of_node;
    struct nmk_i2c_dev *dev;
    struct i2c_adapter *adap;

    + if (np) {
    + if (!pdata) {
    + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
    + if (!pdata) {
    + ret = -ENOMEM;
    + goto err_no_mem;
    + }
    + }
    + ret = nmk_i2c_of_probe(np, pdata);
    + if (ret)
    + kfree(pdata);
    + }
    +
    + if (!pdata)
    + /* No i2c configuration found, using the default. */
    + pdata = &u8500_i2c;
    +
    dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
    if (!dev) {
    dev_err(&pdev->dev, "cannot allocate memory\n");
    @@ -974,12 +1046,10 @@ static int __devinit nmk_i2c_probe(struct platform_device *pdev)

    /* fetch the controller configuration from machine */
    dev->cfg.clk_freq = pdata->clk_freq;
    - dev->cfg.slsu = pdata->slsu;
    - dev->cfg.tft = pdata->tft;
    - dev->cfg.rft = pdata->rft;
    - dev->cfg.sm = pdata->sm;
    -
    - i2c_set_adapdata(adap, dev);
    + dev->cfg.slsu = pdata->slsu;
    + dev->cfg.tft = pdata->tft;
    + dev->cfg.rft = pdata->rft;
    + dev->cfg.sm = pdata->sm; i2c_set_adapdata(adap, dev);

    dev_info(&pdev->dev,
    "initialize %s on virtual base %p\n",
    @@ -1038,11 +1108,17 @@ static int __devexit nmk_i2c_remove(struct platform_device *pdev)
    return 0;
    }

    +static const struct of_device_id nmk_gpio_match[] = {
    + { .compatible = "st,nomadik-i2c", },
    + {},
    +};
    +
    static struct platform_driver nmk_i2c_driver = {
    .driver = {
    .owner = THIS_MODULE,
    .name = DRIVER_NAME,
    .pm = &nmk_i2c_pm,
    + .of_match_table = nmk_gpio_match,
    },
    .probe = nmk_i2c_probe,
    .remove = __devexit_p(nmk_i2c_remove),
    --
    1.7.9.5

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