Hi Rajeshwari,
On Wed, Nov 7, 2012 at 9:30 PM, Rajeshwari Shinde
<rajeshwar...@samsung.com> wrote:
> Functions added to get the I2C bus number and reset I2C bus using
> FDT node.
>
> Signed-off-by: Simon Glass <s...@chromium.org>
> Signed-off-by: Rajeshwari Shinde <rajeshwar...@samsung.com>
> ---
> drivers/i2c/s3c24x0_i2c.c | 89
> ++++++++++++++++++++++++++++++++++++++++++++-
> drivers/i2c/s3c24x0_i2c.h | 7 ++++
> include/i2c.h | 28 ++++++++++++++
> 3 files changed, 123 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/i2c/s3c24x0_i2c.c b/drivers/i2c/s3c24x0_i2c.c
> index 9bc4c7f..952f76c 100644
> --- a/drivers/i2c/s3c24x0_i2c.c
> +++ b/drivers/i2c/s3c24x0_i2c.c
> @@ -27,6 +27,7 @@
> */
>
> #include <common.h>
> +#include <fdtdec.h>
> #ifdef CONFIG_EXYNOS5
> #include <asm/arch/clk.h>
> #include <asm/arch/cpu.h>
> @@ -60,7 +61,14 @@
> #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 +515,83 @@ 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
> +unsigned int i2c_fdt_bus_values(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->node = node;
> + bus->bus_num = i2c_busses++;
> + }
> +
> + return count;
> +}
> +
This seems to be the init function for i2c, so how about calling it
board_i2c_init() or similar. I don't think you need to return the
count of i2c ports - you can just use CONFIG_MAX_I2C_NUM anywhere that
it is needed.
> +static struct s3c24x0_i2c_bus *get_bus(int bus_idx)
should probably be unsigned so that you don't need to check < 0
> +{
> + 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;
> + fdt_addr_t reg;
> + int i;
> +
> + compat = fdtdec_lookup(blob, node);
> + if (compat != COMPAT_SAMSUNG_S3C2440_I2C) {
> + debug("%s: Not a supported I2C node\n", __func__);
> + return -1;
> + }
> + reg = fdtdec_get_addr(blob, node, "reg");
> + for (i = 0; i < i2c_busses; i++) {
> + if (reg == (fdt_addr_t)(uintptr_t)i2c_bus[i].regs)
> + return i;
> + }
This seems painful. You already have a table of node versus bus
number, created in the function above, so why not just look in that?
> +
> + 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..bdd5514 100644
> --- a/drivers/i2c/s3c24x0_i2c.h
> +++ b/drivers/i2c/s3c24x0_i2c.h
> @@ -30,4 +30,11 @@ 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;
> +};
> +
> #endif /* _S3C24X0_I2C_H */
> diff --git a/include/i2c.h b/include/i2c.h
> index 16f099d..52be093 100644
> --- a/include/i2c.h
> +++ b/include/i2c.h
> @@ -262,4 +262,32 @@ extern int get_multi_scl_pin(void);
> extern int get_multi_sda_pin(void);
> extern int multi_i2c_init(void);
> #endif
> +
> +#ifdef CONFIG_OF_CONTROL
I think you can omit this line - it doesn't hurt to have unused
prototypes. We will get a link error if someone does something silly.
> +/**
> + * Get FDT values for i2c bus.
> + *
> + * @param blob Device tree blbo
> + * @return the number of I2C bus
> + */
> +unsigned int i2c_fdt_bus_values(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
> #endif /* _I2C_H_ */
> --
> 1.7.4.4
>
Regards,
Simon
_______________________________________________
U-Boot mailing list
U-Boot@lists.denx.de
http://lists.denx.de/mailman/listinfo/u-boot
