[U-Boot] [PATCH v3 3/7] [REPOST-1] gpio: Add Multi-Function-Pin configuration driver for Marvell SoCs

[Lei Wen]

Hi Prafulla,

On Thu, Dec 2, 2010 at 12:01 AM, Prafulla Wadaskar <prafulla at marvell.com> wrote:
> Most of the Marvell SoCs has Multi Function Pin (MFP) configuration registers
> For ex. ARMADA100.
>
> These registers are programmed to expose the specific functionality
> associated with respective SoC Pins
>
> This driver provides configuration APIs,
> using them, configuration need to be done in board specific code
>
> for ex- following code configures MFPs 107 and 108 for UART_TX/RX functionality
>
> int board_early_init_f(void)
> {
>        u32 mfp_cfg[] = {
>                /* Console on UART1 */
>                MFP107_UART1_RXD,
>                MFP108_UART1_TXD,
>                MFP_EOC         /*End of configureation*/
>        };
>        /* configure MFP's */
>        mfp_config(mfp_cfg);
>        return 0;
> }
>
> Signed-off-by: Prafulla Wadaskar <prafulla at marvell.com>
> ---
> Please Ignore earlier patch, below bufix is added to this patch
>
> Change log v3:
> Fixed: Read-modify-Write a mfg register as per configuration
> ANDed with MASK value before ORing for each configuration
>
> REPOST-V1:
> I am sorry for the repost-V1 :-(
> MASK values changed to relevent (copy paste mistake)
>
> Regards..
> Prafulla . .
>
>  drivers/gpio/Makefile |    1 +
>  drivers/gpio/mfp.c    |  110 +++++++++++++++++++++++++++++++++++++++++++++++++
>  include/mfp.h         |   97 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 208 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/gpio/mfp.c
>  create mode 100644 include/mfp.h
>
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 398024c..f6903d5 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -27,6 +27,7 @@ LIB   := $(obj)libgpio.o
>
>  COBJS-$(CONFIG_AT91_GPIO)      += at91_gpio.o
>  COBJS-$(CONFIG_KIRKWOOD_GPIO)  += kw_gpio.o
> +COBJS-$(CONFIG_MFP)            += mfp.o
>  COBJS-$(CONFIG_MXC_GPIO)       += mxc_gpio.o
>  COBJS-$(CONFIG_PCA953X)                += pca953x.o
>  COBJS-$(CONFIG_S5P)            += s5p_gpio.o
> diff --git a/drivers/gpio/mfp.c b/drivers/gpio/mfp.c
> new file mode 100644
> index 0000000..f26af97
> --- /dev/null
> +++ b/drivers/gpio/mfp.c
> @@ -0,0 +1,110 @@
> +/*
> + * (C) Copyright 2010
> + * Marvell Semiconductor <www.marvell.com>
> + * Written-by: Prafulla Wadaskar <prafulla at marvell.com>,
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
> + * MA 02110-1301 USA
> + */
> +
> +#include <common.h>
> +#include <asm/io.h>
> +#include <mfp.h>
> +#include <asm/arch/mfp.h>
> +#ifdef CONFIG_ARMADA100
> +#include <asm/arch/armada100.h>
> +#define MFPR_BASE      ARMD1_MFPR_BASE;
> +#else
> +#error Unsupported SoC...
> +#endif
> +
> +/*
> + * mfp_config
> + *
> + * On most of Marvell SoCs (ex. ARMADA100) there is Multi-Funtion-Pin
> + * configuration registers to configure each GPIO/Function pin on the
> + * SoC.
> + *
> + * This function reads the array of values for
> + * MFPR_X registers and programms them into respective
> + * Multi-Function Pin registers.
> + * It supports - Alternate Function Selection programming.
> + *
> + * Whereas,
> + * The Configureation value is constructed using ARMD_MFP()
> + * array consists of 32bit values as-
> + * Bits 31-16  : Mfp instance number (i.e. MFPR no. to be programmed)
> + * Bits 15-13  : PULL_UP/PULL_DOWN selection
> + * Bits 11:10  : Pin Driver strength
> + * Bits 6-4    : Edge detection configuration
> + * Bits 2-0    : Alternate Function Selection
> + *
> + * For more details please refer respective Product Software Manual
> + */
> +void mfp_config(u32 *mfp_cfgs)
> +{
> +       u32 *p_mfpr = NULL;
> +       u32 val, cfg_val, mfpr_no;
> +
> +       do {
> +               cfg_val = *mfp_cfgs++;
> +               /* exit if End of configuration table detected */
> +               if (cfg_val == MFP_EOC)
> +                       break;
> +               /* abstract mfpr tobe programmed from configuration value */
> +               mfpr_no = (cfg_val & MFP_PINNO_MASK) >> 16;
> +               BUG_ON(mfpr_no >= MFP_PIN_MAX);
> +
> +               /* the offset address are divided in three regions and not
> +                * consecutive, this corrects the same (Ref: Specs: A1.1) */
> +               p_mfpr = (u32 *)MFPR_BASE;
> +               if ( mfpr_no < 37)
> +                       p_mfpr += (0x004c / 4) + mfpr_no;
> +               else if ( mfpr_no >= 56)
> +                       p_mfpr += (0x00e0 / 4) + (mfpr_no - 56);
> +               else
> +                       p_mfpr += (mfpr_no - 37);

This three regions is only meaningful for armada100, so when we use
the mfp.c to other cpu, like pxa920,
how could we reuse this setting? Obviously, pxa920 is different with
armada100 regions arrangement, with
the start mfp of ND_IO[15].

Best regards,
Lei