[...]
>
>
> From: Lee Jones <lee.jones@xxxxxxxxxx>
> Date: Tue, 17 Apr 2012 16:04:13 +0100
> Subject: [PATCH 1/1] 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@xxxxxxxxxxxxxxx
> Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-nomadik.c | 82 +++++++++++++++++++++++++++++++++++++-
> 1 file changed, 80 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
> index a92440d..58e8114 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,
How is this possible? you are setting clk_freq as 100kb/s and mode
as fast mode which is supposed to be 400kb/s.
> +};
> +
> +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;
The controller has more modes like fast mode plus and high speed mode. You can't make
assumptions like this.
> +
> + 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;
There are redundant fallback configurations exists in the driver. You might need to remove
those, if you want to fallback here.
> +
> dev = kzalloc(sizeof(struct nmk_i2c_dev), GFP_KERNEL);
> if (!dev) {
> dev_err(&pdev->dev, "cannot allocate memory\n");
> @@ -1038,11 +1110,17 @@ 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
>
/srinidhi
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