blob: 0af83e8b0306cd6929ee9405d57a86ef383bc49a [file] [log] [blame]
/* 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.
*/
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <mach/gpiomux.h>
struct msm_gpiomux_rec {
struct gpiomux_setting *sets[GPIOMUX_NSETTINGS];
int ref;
};
static DEFINE_SPINLOCK(gpiomux_lock);
static struct msm_gpiomux_rec *msm_gpiomux_recs;
static struct gpiomux_setting *msm_gpiomux_sets;
static unsigned msm_gpiomux_ngpio;
int msm_gpiomux_write(unsigned gpio, enum msm_gpiomux_setting which,
struct gpiomux_setting *setting, struct gpiomux_setting *old_setting)
{
struct msm_gpiomux_rec *rec = msm_gpiomux_recs + gpio;
unsigned set_slot = gpio * GPIOMUX_NSETTINGS + which;
unsigned long irq_flags;
struct gpiomux_setting *new_set;
int status = 0;
if (!msm_gpiomux_recs)
return -EFAULT;
if (gpio >= msm_gpiomux_ngpio)
return -EINVAL;
spin_lock_irqsave(&gpiomux_lock, irq_flags);
if (old_setting) {
if (rec->sets[which] == NULL)
status = 1;
else
*old_setting = *(rec->sets[which]);
}
if (setting) {
msm_gpiomux_sets[set_slot] = *setting;
rec->sets[which] = &msm_gpiomux_sets[set_slot];
} else {
rec->sets[which] = NULL;
}
new_set = rec->ref ? rec->sets[GPIOMUX_ACTIVE] :
rec->sets[GPIOMUX_SUSPENDED];
if (new_set)
__msm_gpiomux_write(gpio, *new_set);
spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
return status;
}
EXPORT_SYMBOL(msm_gpiomux_write);
int msm_gpiomux_get(unsigned gpio)
{
struct msm_gpiomux_rec *rec = msm_gpiomux_recs + gpio;
unsigned long irq_flags;
if (!msm_gpiomux_recs)
return -EFAULT;
if (gpio >= msm_gpiomux_ngpio)
return -EINVAL;
spin_lock_irqsave(&gpiomux_lock, irq_flags);
if (rec->ref++ == 0 && rec->sets[GPIOMUX_ACTIVE])
__msm_gpiomux_write(gpio, *rec->sets[GPIOMUX_ACTIVE]);
spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
return 0;
}
EXPORT_SYMBOL(msm_gpiomux_get);
int msm_gpiomux_put(unsigned gpio)
{
struct msm_gpiomux_rec *rec = msm_gpiomux_recs + gpio;
unsigned long irq_flags;
if (!msm_gpiomux_recs)
return -EFAULT;
if (gpio >= msm_gpiomux_ngpio)
return -EINVAL;
spin_lock_irqsave(&gpiomux_lock, irq_flags);
BUG_ON(rec->ref == 0);
if (--rec->ref == 0 && rec->sets[GPIOMUX_SUSPENDED])
__msm_gpiomux_write(gpio, *rec->sets[GPIOMUX_SUSPENDED]);
spin_unlock_irqrestore(&gpiomux_lock, irq_flags);
return 0;
}
EXPORT_SYMBOL(msm_gpiomux_put);
int msm_gpiomux_init(size_t ngpio)
{
if (!ngpio)
return -EINVAL;
if (msm_gpiomux_recs)
return -EPERM;
msm_gpiomux_recs = kzalloc(sizeof(struct msm_gpiomux_rec) * ngpio,
GFP_KERNEL);
if (!msm_gpiomux_recs)
return -ENOMEM;
/* There is no need to zero this memory, as clients will be blindly
* installing settings on top of it.
*/
msm_gpiomux_sets = kmalloc(sizeof(struct gpiomux_setting) * ngpio *
GPIOMUX_NSETTINGS, GFP_KERNEL);
if (!msm_gpiomux_sets) {
kfree(msm_gpiomux_recs);
msm_gpiomux_recs = NULL;
return -ENOMEM;
}
msm_gpiomux_ngpio = ngpio;
return 0;
}
EXPORT_SYMBOL(msm_gpiomux_init);
void msm_gpiomux_install(struct msm_gpiomux_config *configs, unsigned nconfigs)
{
unsigned c, s;
int rc;
for (c = 0; c < nconfigs; ++c) {
for (s = 0; s < GPIOMUX_NSETTINGS; ++s) {
rc = msm_gpiomux_write(configs[c].gpio, s,
configs[c].settings[s], NULL);
if (rc)
pr_err("%s: write failure: %d\n", __func__, rc);
}
}
}
EXPORT_SYMBOL(msm_gpiomux_install);
int msm_gpiomux_init_dt(void)
{
int rc;
unsigned int ngpio;
struct device_node *of_gpio_node;
of_gpio_node = of_find_compatible_node(NULL, NULL, "qcom,msm-gpio");
if (!of_gpio_node) {
pr_err("%s: Failed to find qcom,msm-gpio node\n", __func__);
return -ENODEV;
}
rc = of_property_read_u32(of_gpio_node, "ngpio", &ngpio);
if (rc) {
pr_err("%s: Failed to find ngpio property in msm-gpio device node %d\n"
, __func__, rc);
return rc;
}
return msm_gpiomux_init(ngpio);
}
EXPORT_SYMBOL(msm_gpiomux_init_dt);