/*
* AppliedMicro X-Gene SoC GPIO-Standby Driver
*
* Copyright (c) 2014, Applied Micro Circuits Corporation
* Author: Tin Huynh <tnhuynh@apm.com>.
* Y Vo <yvo@apm.com>.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/module.h>
#include <linux/io.h>
#include <linux/platform_device.h>
#include <linux/of_gpio.h>
#include <linux/gpio.h>
#include <linux/gpio/driver.h>
#include <linux/basic_mmio_gpio.h>
#define XGENE_MAX_GPIO_DS 22
#define XGENE_MAX_GPIO_DS_IRQ 6
#define GPIO_MASK(x) (1U << ((x) % 32))
#define MPA_GPIO_INT_LVL 0x0290
#define MPA_GPIO_OE_ADDR 0x029c
#define MPA_GPIO_OUT_ADDR 0x02a0
#define MPA_GPIO_IN_ADDR 0x02a4
#define MPA_GPIO_SEL_LO 0x0294
/**
* struct xgene_gpio_sb - GPIO-Standby private data structure.
* @bgc: memory-mapped GPIO controllers.
* @irq: Mapping GPIO pins and interrupt number
* nirq: Number of GPIO pins that supports interrupt
*/
struct xgene_gpio_sb {
struct bgpio_chip bgc;
u32 *irq;
u32 nirq;
};
static inline struct xgene_gpio_sb *to_xgene_gpio_sb(struct gpio_chip *gc)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
return container_of(bgc, struct xgene_gpio_sb, bgc);
}
static void xgene_gpio_set_bit(struct bgpio_chip *bgc, void __iomem *reg, u32 gpio, int val)
{
u32 data;
data = bgc->read_reg(reg);
if (val)
data |= GPIO_MASK(gpio);
else
data &= ~GPIO_MASK(gpio);
bgc->write_reg(reg, data);
}
static int apm_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
{
struct xgene_gpio_sb *priv = to_xgene_gpio_sb(gc);
if (priv->irq[gpio])
return priv->irq[gpio];
return -ENXIO;
}
static int xgene_gpio_sb_probe(struct platform_device *pdev)
{
struct xgene_gpio_sb *priv;
u32 ret, i;
u32 default_lines[] = {0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D};
struct resource *res;
void __iomem *regs;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
regs = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(regs))
return PTR_ERR(regs);
ret = bgpio_init(&priv->bgc, &pdev->dev, 4,
regs + MPA_GPIO_IN_ADDR,
regs + MPA_GPIO_OUT_ADDR, NULL,
regs + MPA_GPIO_OE_ADDR, NULL, 0);
if (ret)
return ret;
priv->bgc.gc.to_irq = apm_gpio_sb_to_irq;
priv->bgc.gc.ngpio = XGENE_MAX_GPIO_DS;
priv->nirq = XGENE_MAX_GPIO_DS_IRQ;
priv->irq = devm_kzalloc(&pdev->dev, sizeof(u32) * XGENE_MAX_GPIO_DS,
GFP_KERNEL);
if (!priv->irq)
return -ENOMEM;
memset(priv->irq, 0, sizeof(u32) * XGENE_MAX_GPIO_DS);
for (i = 0; i < priv->nirq; i++) {
priv->irq[default_lines[i]] = platform_get_irq(pdev, i);
xgene_gpio_set_bit(&priv->bgc, regs + MPA_GPIO_SEL_LO,
default_lines[i] * 2, 1);
xgene_gpio_set_bit(&priv->bgc, regs + MPA_GPIO_INT_LVL, i, 1);
}
platform_set_drvdata(pdev, priv);
ret = gpiochip_add(&priv->bgc.gc);
if (ret)
dev_err(&pdev->dev, "failed to register X-Gene GPIO Standby driver\n");
else
dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
return ret;
}
static int xgene_gpio_sb_remove(struct platform_device *pdev)
{
struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);
return bgpio_remove(&priv->bgc);
}
static const struct of_device_id xgene_gpio_sb_of_match[] = {
{.compatible = "apm,xgene-gpio-sb", },
{},
};
MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);
static struct platform_driver xgene_gpio_sb_driver = {
.driver = {
.name = "xgene-gpio-sb",
.of_match_table = xgene_gpio_sb_of_match,
},
.probe = xgene_gpio_sb_probe,
.remove = xgene_gpio_sb_remove,
};
module_platform_driver(xgene_gpio_sb_driver);
MODULE_AUTHOR("AppliedMicro");
MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
MODULE_LICENSE("GPL");
