1963a2afc8
Add the 'gpiomux' api, which addresses the following shortcomings of existing tlmm api: - gpio power-collapse, which is managed by a peripheral processor on other targets, must be managed by the application processor on the 8x60. - The enable/disable flag of the legacy gpio_tlmm_config api is not applicable on the 8x60, and causes confusion. - The gpio 'direction' bits are meaningless for all func_sel configurations except for generic-gpio mode (func_sel 0), in which case the gpio_direction_* functions should be used. Having these bits in the tlmm api leads to confusion and misuse of the gpiolib api, and they have been removed in gpiomux. - The functional api of the legacy system ran contrary to the typical use-case, which is a single massive configuration at boot. Rather than forcing hundreds of 'config' function calls, the new api allows data to be configured with a single table. gpiomux_get and gpiomux_put are meant to be called automatically when gpio_request and gpio_free are called, giving automatic gpiomux/tlmm control to those drivers/lines with simple power profiles - in the simplest cases, an entry in the gpiomux table and the correct usage of gpiolib is all that is required to get proper gpio power control. Signed-off-by: Gregory Bean <gbean@codeaurora.org> Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
96 lines
2.6 KiB
C
96 lines
2.6 KiB
C
/* Copyright (c) 2010, Code Aurora Forum. 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 version 2 and
|
|
* only version 2 as published by the Free Software Foundation.
|
|
*
|
|
* 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/module.h>
|
|
#include <linux/spinlock.h>
|
|
#include "gpiomux.h"
|
|
|
|
static DEFINE_SPINLOCK(gpiomux_lock);
|
|
|
|
int msm_gpiomux_write(unsigned gpio,
|
|
gpiomux_config_t active,
|
|
gpiomux_config_t suspended)
|
|
{
|
|
struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio;
|
|
unsigned long irq_flags;
|
|
gpiomux_config_t setting;
|
|
|
|
if (gpio >= GPIOMUX_NGPIOS)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&gpiomux_lock, irq_flags);
|
|
|
|
if (active & GPIOMUX_VALID)
|
|
cfg->active = active;
|
|
|
|
if (suspended & GPIOMUX_VALID)
|
|
cfg->suspended = suspended;
|
|
|
|
setting = cfg->ref ? active : suspended;
|
|
if (setting & GPIOMUX_VALID)
|
|
__msm_gpiomux_write(gpio, setting);
|
|
|
|
spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(msm_gpiomux_write);
|
|
|
|
int msm_gpiomux_get(unsigned gpio)
|
|
{
|
|
struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio;
|
|
unsigned long irq_flags;
|
|
|
|
if (gpio >= GPIOMUX_NGPIOS)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&gpiomux_lock, irq_flags);
|
|
if (cfg->ref++ == 0 && cfg->active & GPIOMUX_VALID)
|
|
__msm_gpiomux_write(gpio, cfg->active);
|
|
spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(msm_gpiomux_get);
|
|
|
|
int msm_gpiomux_put(unsigned gpio)
|
|
{
|
|
struct msm_gpiomux_config *cfg = msm_gpiomux_configs + gpio;
|
|
unsigned long irq_flags;
|
|
|
|
if (gpio >= GPIOMUX_NGPIOS)
|
|
return -EINVAL;
|
|
|
|
spin_lock_irqsave(&gpiomux_lock, irq_flags);
|
|
BUG_ON(cfg->ref == 0);
|
|
if (--cfg->ref == 0 && cfg->suspended & GPIOMUX_VALID)
|
|
__msm_gpiomux_write(gpio, cfg->suspended);
|
|
spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL(msm_gpiomux_put);
|
|
|
|
static int __init gpiomux_init(void)
|
|
{
|
|
unsigned n;
|
|
|
|
for (n = 0; n < GPIOMUX_NGPIOS; ++n) {
|
|
msm_gpiomux_configs[n].ref = 0;
|
|
if (!(msm_gpiomux_configs[n].suspended & GPIOMUX_VALID))
|
|
continue;
|
|
__msm_gpiomux_write(n, msm_gpiomux_configs[n].suspended);
|
|
}
|
|
return 0;
|
|
}
|
|
postcore_initcall(gpiomux_init);
|