[U-Boot] [PATCH 5/6 V2] I2C: Driver changes for FDT support

[Simon Glass <sjg@chromium.org>]

Hi,

On Wed, Nov 14, 2012 at 1:11 AM, Rajeshwari Shinde
<rajeshwari.s@samsung.com> wrote:
> Functions added to get the I2C bus number and reset I2C bus using
> FDT node.
>
> Signed-off-by: Simon Glass <sjg@chromium.org>
> Signed-off-by: Rajeshwari Shinde <rajeshwari.s@samsung.com>
> ---
> Changes in V2:
>         - Added periph id to I2C bus structure.
>         - Modified i2c_get_bus_num_fdt function to compare with node.
>         - Board i2c init moved to driver in case of FDT.

This looks good to me, apart from a small thing you can probably drop below.

>  drivers/i2c/s3c24x0_i2c.c |   90 ++++++++++++++++++++++++++++++++++++++++++++-
>  drivers/i2c/s3c24x0_i2c.h |    8 ++++
>  include/i2c.h             |   26 +++++++++++++
>  3 files changed, 123 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/i2c/s3c24x0_i2c.c b/drivers/i2c/s3c24x0_i2c.c
> index 9bc4c7f..840585d 100644
> --- a/drivers/i2c/s3c24x0_i2c.c
> +++ b/drivers/i2c/s3c24x0_i2c.c
> @@ -27,9 +27,11 @@
>   */
>
>  #include <common.h>
> +#include <fdtdec.h>
>  #ifdef CONFIG_EXYNOS5
>  #include <asm/arch/clk.h>
>  #include <asm/arch/cpu.h>
> +#include <asm/arch/pinmux.h>
>  #else
>  #include <asm/arch/s3c24x0_cpu.h>
>  #endif
> @@ -60,7 +62,14 @@
>  #define I2C_TIMEOUT 1          /* 1 second */
>
>
> -static unsigned int g_current_bus;     /* Stores Current I2C Bus */
> +/*
> + * For SPL boot some boards need i2c before SDRAM is initialised so force
> + * variables to live in SRAM
> + */
> +static unsigned int g_current_bus __attribute__((section(".data")));
> +static struct s3c24x0_i2c_bus i2c_bus[CONFIG_MAX_I2C_NUM]
> +                       __attribute__((section(".data")));
> +static int i2c_busses __attribute__((section(".data")));
>
>  #ifndef CONFIG_EXYNOS5
>  static int GetI2CSDA(void)
> @@ -507,4 +516,83 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
>                 (i2c, I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer,
>                  len) != 0);
>  }
> +
> +#ifdef CONFIG_OF_CONTROL
> +void board_i2c_init(const void *blob)
> +{
> +
> +       int node_list[CONFIG_MAX_I2C_NUM];
> +       int count, i;
> +
> +       count = fdtdec_find_aliases_for_id(blob, "i2c",
> +               COMPAT_SAMSUNG_S3C2440_I2C, node_list,
> +               CONFIG_MAX_I2C_NUM);
> +       for (i = 0; i < count; i++) {
> +               struct s3c24x0_i2c_bus *bus;
> +               int node = node_list[i];
> +
> +               if (node < 0)
> +                       continue;
> +               bus = &i2c_bus[i];
> +               bus->regs = (struct s3c24x0_i2c *)
> +                       fdtdec_get_addr(blob, node, "reg");
> +               bus->id = (enum periph_id)
> +                       fdtdec_get_int(blob, node, "samsung,periph-id", -1);
> +               bus->node = node;
> +               bus->bus_num = i2c_busses++;
> +               exynos_pinmux_config(bus->id, 0);
> +       }
> +
> +}
> +
> +static struct s3c24x0_i2c_bus *get_bus(unsigned int bus_idx)
> +{
> +       if (bus_idx < i2c_busses)
> +               return &i2c_bus[bus_idx];
> +       debug("Undefined bus: %d\n", bus_idx);
> +       return NULL;
> +}
> +
> +int i2c_get_bus_num_fdt(const void *blob, int node)
> +{
> +       enum fdt_compat_id compat;
> +       int i;
> +
> +       compat = fdtdec_lookup(blob, node);
> +       if (compat != COMPAT_SAMSUNG_S3C2440_I2C) {
> +               debug("%s: Not a supported I2C node\n", __func__);
> +               return -1;
> +       }

I think you can drop this check, since your code immediately below
will handle a missing node.

> +       for (i = 0; i < i2c_busses; i++) {
> +               if (node == i2c_bus[i].node)
> +                       return i;
> +       }
> +
> +       debug("%s: Can't find any matched I2C bus\n", __func__);
> +       return -1;
> +}
> +
> +int i2c_reset_port_fdt(const void *blob, int node)
> +{
> +       struct s3c24x0_i2c_bus *i2c;
> +
> +       int bus;
> +
> +       bus = i2c_get_bus_num_fdt(blob, node);
> +       if (bus < 0) {
> +               debug("could not get bus for node %d\n", node);
> +               return -1;
> +       }
> +       i2c = get_bus(bus);
> +       if (!i2c) {
> +               debug("get_bus() failed for node node %d\n", node);
> +               return -1;
> +       }
> +
> +       i2c_ch_init(i2c->regs, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
> +
> +       return 0;
> +}
> +#endif
> +
>  #endif /* CONFIG_HARD_I2C */
> diff --git a/drivers/i2c/s3c24x0_i2c.h b/drivers/i2c/s3c24x0_i2c.h
> index 2dd4b06..1243bf1 100644
> --- a/drivers/i2c/s3c24x0_i2c.h
> +++ b/drivers/i2c/s3c24x0_i2c.h
> @@ -30,4 +30,12 @@ struct s3c24x0_i2c {
>         u32     iicds;
>         u32     iiclc;
>  };
> +
> +struct s3c24x0_i2c_bus {
> +       int node;       /* device tree node */
> +       int bus_num;    /* i2c bus number */
> +       struct s3c24x0_i2c *regs;
> +       enum periph_id id;
> +};
> +
>  #endif /* _S3C24X0_I2C_H */
> diff --git a/include/i2c.h b/include/i2c.h
> index 16f099d..efb097f 100644
> --- a/include/i2c.h
> +++ b/include/i2c.h
> @@ -262,4 +262,30 @@ extern int get_multi_scl_pin(void);
>  extern int get_multi_sda_pin(void);
>  extern int multi_i2c_init(void);
>  #endif
> +
> +/**
> + * Get FDT values for i2c bus.
> + *
> + * @param blob  Device tree blbo
> + * @return the number of I2C bus
> + */
> +void board_i2c_init(const void *blob);
> +
> +/**
> + * Find the I2C bus number by given a FDT I2C node.
> + *
> + * @param blob  Device tree blbo
> + * @param node  FDT I2C node to find
> + * @return the number of I2C bus (zero based), or -1 on error
> + */
> +int i2c_get_bus_num_fdt(const void *blob, int node);
> +
> +/**
> + * Reset the I2C bus represented by the given a FDT I2C node.
> + *
> + * @param blob  Device tree blbo
> + * @param node  FDT I2C node to find
> + * @return 0 if port was reset, -1 if not found
> + */
> +int i2c_reset_port_fdt(const void *blob, int node);
>  #endif /* _I2C_H_ */
> --
> 1.7.4.4
>

Regards,
Simon