[PATCH v3 07/15] ARM: mxs: Add gpio support

[Shawn Guo]

On Fri, Dec 10, 2010 at 3:06 PM, Shawn Guo <shawn.gsc at gmail.com> wrote:
> Hi Lothar,
>
> On Fri, Dec 10, 2010 at 12:47 AM, Lothar Waßmann <LW at karo-electronics.de> wrote:
>> Hi,
>>
>> Shawn Guo writes:
>>> MXS-based SoCs implement gpio support in block PINCTRL.
>>>
>>> Signed-off-by: Shawn Guo <shawn.guo at freescale.com>
>>> ---
>>> Changes for v3:
>>>  - include/mach/gpio.h: remove the inclusion of hardware.h
>>>  - gpio.c: change inclusion of hardware.h to mx23.h plus mx28.h
>>>  - Remove spinlock totally since SET/CLE can be used in all the
>>>    gpio register access
>>>
>>> Changes for v2:
>>>  - Create arch/arm/mach-mxs/gpio.h to accommodate stuff private for mach-mxs
>>>  - Use GPIO_INT_LEV_MASK and GPIO_INT_POL_MASK instead of constant
>>>  - Remove both edges IRQ support which is not needed
>>>  - Use SET and CLR register of PINCTRL_DOE in _set_gpio_direction()
>>>  - Use pr_info over printk(KERN_INFO)
>>>
>>>  arch/arm/mach-mxs/gpio.c              |  321 +++++++++++++++++++++++++++++++++
>>>  arch/arm/mach-mxs/gpio.h              |   33 ++++
>>>  arch/arm/mach-mxs/include/mach/gpio.h |   34 ++++
>>>  3 files changed, 388 insertions(+), 0 deletions(-)
>>>  create mode 100644 arch/arm/mach-mxs/gpio.c
>>>  create mode 100644 arch/arm/mach-mxs/gpio.h
>>>  create mode 100644 arch/arm/mach-mxs/include/mach/gpio.h
>>>
>>> diff --git a/arch/arm/mach-mxs/gpio.c b/arch/arm/mach-mxs/gpio.c
>>> new file mode 100644
>>> index 0000000..d88acf3
>>> --- /dev/null
>>> +++ b/arch/arm/mach-mxs/gpio.c
>>> @@ -0,0 +1,321 @@
>>> +/*
>>> + * MXC GPIO support. (c) 2008 Daniel Mack <daniel at caiaq.de>
>>> + * Copyright 2008 Juergen Beisert, kernel at pengutronix.de
>>> + *
>>> + * Based on code from Freescale,
>>> + * Copyright (C) 2004-2010 Freescale Semiconductor, Inc. All Rights Reserved.
>>> + *
>>> + * 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 <linux/init.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/io.h>
>>> +#include <linux/irq.h>
>>> +#include <linux/gpio.h>
>>> +#include <mach/mx23.h>
>>> +#include <mach/mx28.h>
>>> +#include <asm-generic/bug.h>
>>> +
>>> +#include "gpio.h"
>>> +
>>> +static struct mxs_gpio_port *mxs_gpio_ports;
>>> +static int gpio_table_size;
>>> +
>>> +#define PINCTRL_DOUT(n)              ((cpu_is_mx23() ? 0x0500 : 0x0700) + (n) * 0x10)
>>> +#define PINCTRL_DIN(n)               ((cpu_is_mx23() ? 0x0600 : 0x0900) + (n) * 0x10)
>>> +#define PINCTRL_DOE(n)               ((cpu_is_mx23() ? 0x0700 : 0x0b00) + (n) * 0x10)
>>> +#define PINCTRL_PIN2IRQ(n)   ((cpu_is_mx23() ? 0x0800 : 0x1000) + (n) * 0x10)
>>> +#define PINCTRL_IRQEN(n)     ((cpu_is_mx23() ? 0x0900 : 0x1100) + (n) * 0x10)
>>> +#define PINCTRL_IRQLEV(n)    ((cpu_is_mx23() ? 0x0a00 : 0x1200) + (n) * 0x10)
>>> +#define PINCTRL_IRQPOL(n)    ((cpu_is_mx23() ? 0x0b00 : 0x1300) + (n) * 0x10)
>>> +#define PINCTRL_IRQSTAT(n)   ((cpu_is_mx23() ? 0x0c00 : 0x1400) + (n) * 0x10)
>>> +
>>> +#define GPIO_INT_FALL_EDGE   0x0
>>> +#define GPIO_INT_LOW_LEV     0x1
>>> +#define GPIO_INT_RISE_EDGE   0x2
>>> +#define GPIO_INT_HIGH_LEV    0x3
>>> +#define GPIO_INT_LEV_MASK    (1 << 0)
>>> +#define GPIO_INT_POL_MASK    (1 << 1)
>>> +
>>> +/* Note: This driver assumes 32 GPIOs are handled in one register */
>>> +
>>> +static void _clear_gpio_irqstatus(struct mxs_gpio_port *port, u32 index)
>>> +{
>>> +     __raw_writel(1 << index,
>>> +                     port->base + PINCTRL_IRQSTAT(port->id) + MXS_CLR_ADDR);
>>> +}
>>> +
>>> +static void _set_gpio_irqenable(struct mxs_gpio_port *port, u32 index,
>>> +                             int enable)
>>> +{
>>> +     if (enable == 0) {
>>> +             __raw_writel(1 << index,
>>> +                     port->base + PINCTRL_PIN2IRQ(port->id) + MXS_CLR_ADDR);
>>> +             __raw_writel(1 << index,
>>> +                     port->base + PINCTRL_IRQEN(port->id) + MXS_CLR_ADDR);
>> This will loose interrupt pulses that happen while IRQs are disabled.
>> IMO PIN2IRQ should only be cleared when an IRQ is freed, not when it
>> is disabled.
>>
> What about leaving PIN2IRQ always be 1 and only using IRQEN to
> enable/disable IRQ?  I consulted the designer it's no problem no
> matter what the pin function is.
>
The code will be like:

static void _set_gpio_irqenable(struct mxs_gpio_port *port, u32 index,
                                int enable)
{
        if (enable) {
                __raw_writel(1 << index,
                        port->base + PINCTRL_IRQEN(port->id) + MXS_SET_ADDR);
                __raw_writel(1 << index,
                        port->base + PINCTRL_PIN2IRQ(port->id) + MXS_SET_ADDR);
        } else {
                __raw_writel(1 << index,
                        port->base + PINCTRL_IRQEN(port->id) + MXS_CLR_ADDR);
        }
}


-- 
Regards,
Shawn