[U-Boot] [PATCH v3 4/4] dm:gpio:mxc add DT support

[Peng Fan]

Hi Simon,

On 1/23/2015 5:26 AM, Simon Glass wrote:
> Hi Peng,
>
> On 21 January 2015 at 04:09, Peng Fan <Peng.Fan at freescale.com> wrote:
>> This patch add DT support for mxc gpio driver.
>>
>> There are one place using CONFIG_OF_CONTROL macro.
>> 1. The U_BOOT_DEVICES and mxc_plat array are complied out. To DT,
>>     platdata is alloced using calloc, so there is no need to use mxc_plat.
>>
>> The following situations are tested, and all work fine:
>> 1. with DM, without DT
>> 2. with DM and DT
>> 3. without DM
>> Since device tree has not been upstreamed, if want to test this patch.
>> The followings need to be done.
>>   + pieces of code does not gpio_request when using gpio_direction_xxx and
>>     etc, need to request gpio.
>>   + move the gpio settings from board_early_init_f to board_init
>>   + define CONFIG_DM ,CONFIG_DM_GPIO and CONFIG_OF_CONTROL
>>   + Add device tree file and do related configuration in
>>     `make ARCH=arm menuconfig`
>> These will be done in future patches by step.
>>
>> Signed-off-by: Peng Fan <Peng.Fan at freescale.com>
>> ---
>>   drivers/gpio/mxc_gpio.c | 69 +++++++++++++++++++++++++++++++++++++------------
>>   1 file changed, 52 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpio/mxc_gpio.c b/drivers/gpio/mxc_gpio.c
>> index c52dd19..0766b78 100644
>> --- a/drivers/gpio/mxc_gpio.c
>> +++ b/drivers/gpio/mxc_gpio.c
>> @@ -151,6 +151,9 @@ int gpio_direction_output(unsigned gpio, int value)
>>   #endif
>>
>>   #ifdef CONFIG_DM_GPIO
>> +#include <fdtdec.h>
>> +DECLARE_GLOBAL_DATA_PTR;
>> +
>>   static int mxc_gpio_is_output(struct gpio_regs *regs, int offset)
>>   {
>>          u32 val;
>> @@ -259,23 +262,6 @@ static const struct dm_gpio_ops gpio_mxc_ops = {
>>          .get_function           = mxc_gpio_get_function,
>>   };
>>
>> -static const struct mxc_gpio_plat mxc_plat[] = {
>> -       { 0, (struct gpio_regs *)GPIO1_BASE_ADDR },
>> -       { 1, (struct gpio_regs *)GPIO2_BASE_ADDR },
>> -       { 2, (struct gpio_regs *)GPIO3_BASE_ADDR },
>> -#if defined(CONFIG_MX25) || defined(CONFIG_MX27) || defined(CONFIG_MX51) || \
>> -               defined(CONFIG_MX53) || defined(CONFIG_MX6)
>> -       { 3, (struct gpio_regs *)GPIO4_BASE_ADDR },
>> -#endif
>> -#if defined(CONFIG_MX27) || defined(CONFIG_MX53) || defined(CONFIG_MX6)
>> -       { 4, (struct gpio_regs *)GPIO5_BASE_ADDR },
>> -       { 5, (struct gpio_regs *)GPIO6_BASE_ADDR },
>> -#endif
>> -#if defined(CONFIG_MX53) || defined(CONFIG_MX6)
>> -       { 6, (struct gpio_regs *)GPIO7_BASE_ADDR },
>> -#endif
>> -};
>> -
>>   static int mxc_gpio_probe(struct udevice *dev)
>>   {
>>          struct mxc_bank_info *bank = dev_get_priv(dev);
>> @@ -296,12 +282,60 @@ static int mxc_gpio_probe(struct udevice *dev)
>>          return 0;
>>   }
>>
>> +static int mxc_gpio_bind(struct udevice *device)
> s/device/dev/ as that is the convention.
Will fix this.
>
>> +{
>> +       struct mxc_gpio_plat *plat = device->platdata;
>> +       struct gpio_regs *regs;
>> +
>> +       if (plat)
>> +               return 0;
> Please add a comment as to why.
Ok.
>
>> +
>> +       regs = dev_get_addr(device);
>> +       if (!regs)
>> +               return -ENXIO;
> -ENODEV I think?
Yeah. Right.
>> +
>> +       plat = calloc(1, sizeof(*plat));
>> +       if (!plat)
>> +               return -ENOMEM;
> Can you use the auto-alloc feature instead? Trying to keep memory
> allocations out of drivers unless it is for buffers, etc.
I want the DM code can support DT and no DT. To no DT, platdata is 
defined in U_BOOT_DEVICES.
If using auto-alloc feature, but DT is not supported, is it conflict 
with platdata in U_BOOT_DEVICES?
>
>> +
>> +       plat->regs = regs;
>> +       plat->bank_index = device->req_seq;
> Why store this? You can access it anytime using the device pointer.
To no DT, bank_index is statically intialized  in mxc_plat array. I do 
not want to introudce `#ifdef CONFIG_OF_CONTROL` in probe function and 
introudce `if (dev->of_offset == -1)`, so
store it to bank_index.
To no DT, `if(plat) return 0;` will return. So plat->bank_index = 
device->req_seq will only effects for DT.
Just want to support DT and no DT.
>
>> +       device->platdata = plat;
>> +
>> +       return 0;
>> +}
>> +
>> +static const struct udevice_id mxc_gpio_ids[] = {
>> +       { .compatible = "fsl,imx35-gpio" },
>> +       { }
>> +};
>> +
>>   U_BOOT_DRIVER(gpio_mxc) = {
>>          .name   = "gpio_mxc",
>>          .id     = UCLASS_GPIO,
>>          .ops    = &gpio_mxc_ops,
>>          .probe  = mxc_gpio_probe,
>>          .priv_auto_alloc_size = sizeof(struct mxc_bank_info),
>> +       .of_match = mxc_gpio_ids,
> Masahiro added a function for this.:
>
>         .of_match = of_match_ptr(mxc_gpio_ids),
>
> But I'm not completely sure if this is wanted, since you include this
> information even when not using device tree.
Thanks,I'll try this. I am not sure whether using of_match_ptr will make 
compiler complain mxc_gpio_ids `defined but not used` for no DT, since 
`#ifdef xx` is not recommended to compiled out `mxc_gpio_ids` for no DT.
>
>> +       .bind   = mxc_gpio_bind,
>> +};
>> +
>> +#ifndef CONFIG_OF_CONTROL
>> +static const struct mxc_gpio_plat mxc_plat[] = {
>> +       { 0, (struct gpio_regs *)GPIO1_BASE_ADDR },
>> +       { 1, (struct gpio_regs *)GPIO2_BASE_ADDR },
>> +       { 2, (struct gpio_regs *)GPIO3_BASE_ADDR },
>> +#if defined(CONFIG_MX25) || defined(CONFIG_MX27) || defined(CONFIG_MX51) || \
>> +               defined(CONFIG_MX53) || defined(CONFIG_MX6)
>> +       { 3, (struct gpio_regs *)GPIO4_BASE_ADDR },
>> +#endif
>> +#if defined(CONFIG_MX27) || defined(CONFIG_MX53) || defined(CONFIG_MX6)
>> +       { 4, (struct gpio_regs *)GPIO5_BASE_ADDR },
>> +       { 5, (struct gpio_regs *)GPIO6_BASE_ADDR },
>> +#endif
>> +#if defined(CONFIG_MX53) || defined(CONFIG_MX6)
>> +       { 6, (struct gpio_regs *)GPIO7_BASE_ADDR },
>> +#endif
> Can we remove the casts by changing the type to ulong?
Hmm, this patch is just to make this driver can support DT. This will 
introduce more change. Also, changing the type to ulong will change 
mxc_gpio_plat struct.
If change the type to ulong, functions in this driver that uses platdata 
will casts it to `struct gpio_regs *`. So i'd like not to remove the 
casts, since remove them in mxc_plat will introduce casts in other 
functions which use the platdata.
>
>>   };
>>
>>   U_BOOT_DEVICES(mxc_gpios) = {
>> @@ -321,3 +355,4 @@ U_BOOT_DEVICES(mxc_gpios) = {
>>   #endif
>>   };
>>   #endif
>> +#endif
>> --
>> 1.8.4
>>
>>
> Regards,
> Simon
Regards,
Peng.