Hi Rajeshwari,
On Mon, Nov 12, 2012 at 5:03 AM, Rajeshwari Birje
<rajeshwari.bi...@gmail.com> wrote:
> Hi Simon Glass,
>
> Thank you for comments.
>
> On Fri, Nov 9, 2012 at 6:34 AM, Simon Glass <s...@chromium.org> wrote:
>> 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?
>>
> You want me to use get_bus function? but that function takes the bus
> number and gives the handle to the structure and not the i2c channel
> register address. Hence we cannot use that function here, instead I am
> using the structures populated in board_i2c_init.
> Do clarify if I have misunderstood the comment.
What I mean is that you have set up a table of node versus bus number
in i2c_fdt_bus_values(). So there should be no need to go and look
again at the fdt in i2c_get_bus_num_fdt() - you can just write a
function to search your table.
[snip]
Regards,
Simon
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