[U-Boot] [PATCH v4 2/7] gpio: Add Multi-Function-Pin configuration driver for Marvell SoCs

Lei Wen adrian.wenl at gmail.com
Tue Dec 7 16:23:19 CET 2010


Hi Prafulla,

On Wed, Dec 8, 2010 at 1:06 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>
> ---
> Changelog v4:
> 1. Driver renamed as mvmfp
> 2. Re-architected mvmfp driver as per review feedback
>
>  drivers/gpio/Makefile |    1 +
>  drivers/gpio/mvmfp.c  |   90 ++++++++++++++++++++++++++++++++++++++++++++
>  include/mvmfp.h       |  100 +++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 191 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/gpio/mvmfp.c
>  create mode 100644 include/mvmfp.h
>
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 398024c..a5fa2b5 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_MARVELL_MFP)    += mvmfp.o
>  COBJS-$(CONFIG_MXC_GPIO)       += mxc_gpio.o
>  COBJS-$(CONFIG_PCA953X)                += pca953x.o
>  COBJS-$(CONFIG_S5P)            += s5p_gpio.o
> diff --git a/drivers/gpio/mvmfp.c b/drivers/gpio/mvmfp.c
> new file mode 100644
> index 0000000..3472278
> --- /dev/null
> +++ b/drivers/gpio/mvmfp.c
> @@ -0,0 +1,90 @@
> +/*
> + * (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 <mvmfp.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

Why not directly name a CONFIG_MFPR_BASE, and define its value in the
config file?
If we do like this ifdef, we may need do add each arch here, seems
some kind of redundant?


> +
> +/*
> + * 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 MFP()
> + * array consists of 32bit values as defined in MFP(xx,xx..) macro
> + */
> +void mfp_config(u32 *mfp_cfgs)
> +{
> +       u32 *p_mfpr = NULL;
> +       u32 cfg_val, val=0;
> +
> +       do {
> +               cfg_val = *mfp_cfgs++;
> +               /* exit if End of configuration table detected */
> +               if (cfg_val == MFP_EOC)
> +                       break;
> +
> +               p_mfpr = (u32 *)(MFPR_BASE + MFP_REG_GET_OFFSET(cfg_val));



> +
> +               /* Write a mfg register as per configuration */
> +               if (cfg_val & MFP_AF_FLAG) {
> +                       /* Abstract and program Afternate-Func Selection */
> +                       val &= ~MFP_AF_MASK;
Do we need to do this & here? For val is only 0 here...
Should not it be more concise like:
writel(cfg_val, p_mfpr);


> +                       val |= cfg_val & MFP_AF_MASK;
> +               } if (cfg_val & MFP_EDGE_FLAG) {
> +                       /* Abstract and program Edge configuration */
> +                       val &= ~MFP_LPM_EDGE_MASK;
> +                       val |= cfg_val & MFP_LPM_EDGE_MASK;
> +               } if (cfg_val & MFP_DRIVE_FLAG) {
> +                       /* Abstract and program Drive configuration */
> +                       val &= ~MFP_DRIVE_MASK;
> +                       val |= cfg_val & MFP_DRIVE_MASK;
> +               } if (cfg_val & MFP_PULL_FLAG) {
> +                       /* Abstract and program Pullup/down configuration */
> +                       val &= ~MFP_PULL_MASK;
> +                       val |= cfg_val & MFP_PULL_MASK;
> +               }
> +               writel(val, p_mfpr);
> +       } while (1);
> +       /*
> +        * perform a read-back of any MFPR register to make sure the
> +        * previous writings are finished
> +        */
> +       readl(p_mfpr);
> +}
> diff --git a/include/mvmfp.h b/include/mvmfp.h
> new file mode 100644
> index 0000000..0b36393
> --- /dev/null
> +++ b/include/mvmfp.h
> @@ -0,0 +1,100 @@
> +/*
> + * (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
> + */
> +
> +#ifndef __MVMFP_H
> +#define __MVMFP_H
> +
> +/*
> + * Header file for MultiFunctionPin (MFP) Configururation framework
> + *
> + * Processors Supported:
> + * 1. Marvell ARMADA100 Processors
> + *
> + * processor to be supported should be added here
> + */
> +
> +/*
> + * MFP configuration is represented by a 32-bit unsigned integer
> + */
> +#define MFP(_off, _pull, _pF, _drv, _dF, _edge, _eF, _afn, _aF) ( \
> +       /* bits 31..16 - MFP Register Offset */ (((_off) & 0xffff) << 16) | \
> +       /* bits 15..13 - Run Mode Pull State */ (((_pull) & 0x7) << 13) | \
> +       /* bit  12     - Unused */ \
> +       /* bits 11..10 - Driver Strength */     (((_drv) & 0x3) << 10) | \
> +       /* bit  09     - Pull State flag */     (((_pF) & 0x1) << 9) | \
> +       /* bit  08     - Drv-strength flag */   (((_dF) & 0x1) << 8) | \
> +       /* bit  07     - Edge-det flag */       (((_eF) & 0x1) << 7) | \
> +       /* bits 06..04 - Edge Detection */      (((_edge) & 0x7) << 4) | \
> +       /* bits 03..00 - Alt-fun flag */        (((_aF) & 0x1) << 3) | \
> +       /* bits Alternate-fun select */         ((_afn) & 0x7))
> +
> +/*
> + * to facilitate the definition, the following macros are provided
> + *
> + *                                 offset, pull,pF, drv,dF, edge,eF ,afn,aF
> + */
> +#define MFP_OFFSET_MASK                MFP(0xffff,    0,0,    0,0,     0,0,   0,0)
> +#define MFP_REG(x)             MFP(x,         0,0,    0,0,     0,0,   0,0)
> +#define MFP_REG_GET_OFFSET(x)  ((x & MFP_OFFSET_MASK) >> 16)
> +
> +#define MFP_AF_FLAG            MFP(0x0000,    0,0,    0,0,     0,0,   0,1)
> +#define MFP_DRIVE_FLAG         MFP(0x0000,    0,0,    0,1,     0,0,   0,0)
> +#define MFP_EDGE_FLAG          MFP(0x0000,    0,0,    0,0,     0,1,   0,0)
> +#define MFP_PULL_FLAG          MFP(0x0000,    0,1,    0,0,     0,0,   0,0)
> +
> +#define MFP_AF0                        MFP(0x0000,    0,0,    0,0,     0,0,   0,1)
> +#define MFP_AF1                        MFP(0x0000,    0,0,    0,0,     0,0,   1,1)
> +#define MFP_AF2                        MFP(0x0000,    0,0,    0,0,     0,0,   2,1)
> +#define MFP_AF3                        MFP(0x0000,    0,0,    0,0,     0,0,   3,1)
> +#define MFP_AF4                        MFP(0x0000,    0,0,    0,0,     0,0,   4,1)
> +#define MFP_AF5                        MFP(0x0000,    0,0,    0,0,     0,0,   5,1)
> +#define MFP_AF6                        MFP(0x0000,    0,0,    0,0,     0,0,   6,1)
> +#define MFP_AF7                        MFP(0x0000,    0,0,    0,0,     0,0,   7,1)
> +#define MFP_AF_MASK            MFP(0x0000,    0,0,    0,0,     0,0,   7,0)
> +
> +#define MFP_LPM_EDGE_NONE      MFP(0x0000,    0,0,    0,0,     0,1,   0,0)
> +#define MFP_LPM_EDGE_RISE      MFP(0x0000,    0,0,    0,0,     1,1,   0,0)
> +#define MFP_LPM_EDGE_FALL      MFP(0x0000,    0,0,    0,0,     2,1,   0,0)
> +#define MFP_LPM_EDGE_BOTH      MFP(0x0000,    0,0,    0,0,     3,1,   0,0)
> +#define MFP_LPM_EDGE_MASK      MFP(0x0000,    0,0,    0,0,     3,0,   0,0)
> +
> +#define MFP_DRIVE_VERY_SLOW    MFP(0x0000,    0,0,    0,1,     0,0,   0,0)
> +#define MFP_DRIVE_SLOW         MFP(0x0000,    0,0,    1,1,     0,0,   0,0)
> +#define MFP_DRIVE_MEDIUM       MFP(0x0000,    0,0,    2,1,     0,0,   0,0)
> +#define MFP_DRIVE_FAST         MFP(0x0000,    0,0,    3,1,     0,0,   0,0)
> +#define MFP_DRIVE_MASK         MFP(0x0000,    0,0,    3,0,     0,0,   0,0)
> +
> +#define MFP_PULL_NONE          MFP(0x0000,    0,1,    0,0,     0,0,   0,0)
> +#define MFP_PULL_LOW           MFP(0x0000,    1,1,    0,0,     0,0,   0,0)
> +#define MFP_PULL_HIGH          MFP(0x0000,    2,1,    0,0,     0,0,   0,0)
> +#define MFP_PULL_BOTH          MFP(0x0000,    3,1,    0,0,     0,0,   0,0)
> +#define MFP_PULL_FLOAT         MFP(0x0000,    4,1,    0,0,     0,0,   0,0)
> +#define MFP_PULL_MASK          MFP(0x0000,    7,0,    0,0,     0,0,   0,0)
> +
> +#define MFP_EOC                        0xffffffff      /* indicates end-of-conf */
> +
> +/* Functions */
> +void mfp_config(u32 *mfp_cfgs);
> +
> +#endif /* __MVMFP_H */
> --
> 1.5.3.4
>
Best regards,
Lei


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