[U-Boot] [PATCH v2 1/2] gpio: Add GPIO driver framework for Marvell SoCs

[Prafulla Wadaskar]

> -----Original Message-----
> From: Simon Guinot [mailto:simon at sequanux.org]
> Sent: Tuesday, August 02, 2011 7:41 PM
> To: Ajay Bhargav
> Cc: Prafulla Wadaskar; u-boot at lists.denx.de
> Subject: Re: [U-Boot] [PATCH v2 1/2] gpio: Add GPIO driver framework for
> Marvell SoCs
> 
> Hi Ajay,
> 
> On Fri, Jul 22, 2011 at 12:46:33PM +0530, Ajay Bhargav wrote:
> > This patch adds generic GPIO driver framework support for Marvell
> SoCs.
> >
> > To enable GPIO driver define CONFIG_MARVELL_GPIO and for GPIO commands
> > define CONFIG_CMD_GPIO in your board configuration file.
> >
> > Signed-off-by: Ajay Bhargav <ajay.bhargav at einfochips.com>
> > ---
> >  drivers/gpio/Makefile |    1 +
> >  drivers/gpio/mvgpio.c |  114
> +++++++++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 115 insertions(+), 0 deletions(-)
> >  create mode 100644 drivers/gpio/mvgpio.c
> 
> ... snip ...
> 
> > +int gpio_direction_input(int gp)
> > +{
> > +	struct gpio_reg *gpio_reg_bank;
> > +
> > +	if (gp >= MV_MAX_GPIO) {
> > +		printf("%s: Invalid GPIO %d\n", __func__, gp);
> > +		return -EINVAL;
> > +	}
> > +
> > +	gpio_reg_bank = get_gpio_base(GPIO_TO_REG(gp));
> > +	writel(GPIO_TO_BIT(gp), &gpio_reg_bank->gcdr);
> 
> AFAIK, Orion and Kirkwood SoCs don't provide bitwise set/clear for
> GPIO output/direction registers. Instead, a register must be read
> first to leave other bits unchanged (see __set_direction in kw_gpio.c).
> 
> Is it possible to handle Armada SoCs GPIOs in a same way ? maybe using
> the pin registers (gpxx in the Armada struct gpio_reg array) ?
> 
> If not, this code is not Marvell generic but rather specific for Armada
> SoCs and then maybe armada_gpio is a better name...

Hi Simon, you are right.

I think lets keep it mvgpio.c at the moment because most of other Marvell SoC uses this method. Any way Orion and Kirkwood are mainlined, if needed to be supported for this driver we can think of adding some #ifdef or macros to mvgpio.c latter.

Regards..
Prafulla . .