linux/arch/mips/lantiq/xway/gpio_stp.c
John Crispin 935c500c37 MIPS: Lantiq: Add more gpio drivers
The XWAY family allows to extend the number of gpios by using shift
registers or latches. This patch adds the 2 drivers needed for this. The
extended gpios are output only.

[ralf@linux-mips.org: Fixed ltq_stp_probe section() attributes.]

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2258/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2011-05-19 09:55:42 +01:00

158 lines
3.8 KiB
C

/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* Copyright (C) 2007 John Crispin <blogic@openwrt.org>
*
*/
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/mutex.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <lantiq_soc.h>
#define LTQ_STP_CON0 0x00
#define LTQ_STP_CON1 0x04
#define LTQ_STP_CPU0 0x08
#define LTQ_STP_CPU1 0x0C
#define LTQ_STP_AR 0x10
#define LTQ_STP_CON_SWU (1 << 31)
#define LTQ_STP_2HZ 0
#define LTQ_STP_4HZ (1 << 23)
#define LTQ_STP_8HZ (2 << 23)
#define LTQ_STP_10HZ (3 << 23)
#define LTQ_STP_SPEED_MASK (0xf << 23)
#define LTQ_STP_UPD_FPI (1 << 31)
#define LTQ_STP_UPD_MASK (3 << 30)
#define LTQ_STP_ADSL_SRC (3 << 24)
#define LTQ_STP_GROUP0 (1 << 0)
#define LTQ_STP_RISING 0
#define LTQ_STP_FALLING (1 << 26)
#define LTQ_STP_EDGE_MASK (1 << 26)
#define ltq_stp_r32(reg) __raw_readl(ltq_stp_membase + reg)
#define ltq_stp_w32(val, reg) __raw_writel(val, ltq_stp_membase + reg)
#define ltq_stp_w32_mask(clear, set, reg) \
ltq_w32((ltq_r32(ltq_stp_membase + reg) & ~(clear)) | (set), \
ltq_stp_membase + (reg))
static int ltq_stp_shadow = 0xffff;
static void __iomem *ltq_stp_membase;
static void ltq_stp_set(struct gpio_chip *chip, unsigned offset, int value)
{
if (value)
ltq_stp_shadow |= (1 << offset);
else
ltq_stp_shadow &= ~(1 << offset);
ltq_stp_w32(ltq_stp_shadow, LTQ_STP_CPU0);
}
static int ltq_stp_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
ltq_stp_set(chip, offset, value);
return 0;
}
static struct gpio_chip ltq_stp_chip = {
.label = "ltq_stp",
.direction_output = ltq_stp_direction_output,
.set = ltq_stp_set,
.base = 48,
.ngpio = 24,
.can_sleep = 1,
.owner = THIS_MODULE,
};
static int ltq_stp_hw_init(void)
{
/* the 3 pins used to control the external stp */
ltq_gpio_request(4, 1, 0, 1, "stp-st");
ltq_gpio_request(5, 1, 0, 1, "stp-d");
ltq_gpio_request(6, 1, 0, 1, "stp-sh");
/* sane defaults */
ltq_stp_w32(0, LTQ_STP_AR);
ltq_stp_w32(0, LTQ_STP_CPU0);
ltq_stp_w32(0, LTQ_STP_CPU1);
ltq_stp_w32(LTQ_STP_CON_SWU, LTQ_STP_CON0);
ltq_stp_w32(0, LTQ_STP_CON1);
/* rising or falling edge */
ltq_stp_w32_mask(LTQ_STP_EDGE_MASK, LTQ_STP_FALLING, LTQ_STP_CON0);
/* per default stp 15-0 are set */
ltq_stp_w32_mask(0, LTQ_STP_GROUP0, LTQ_STP_CON1);
/* stp are update periodically by the FPI bus */
ltq_stp_w32_mask(LTQ_STP_UPD_MASK, LTQ_STP_UPD_FPI, LTQ_STP_CON1);
/* set stp update speed */
ltq_stp_w32_mask(LTQ_STP_SPEED_MASK, LTQ_STP_8HZ, LTQ_STP_CON1);
/* tell the hardware that pin (led) 0 and 1 are controlled
* by the dsl arc
*/
ltq_stp_w32_mask(0, LTQ_STP_ADSL_SRC, LTQ_STP_CON0);
ltq_pmu_enable(PMU_LED);
return 0;
}
static int __devinit ltq_stp_probe(struct platform_device *pdev)
{
struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
int ret = 0;
if (!res)
return -ENOENT;
res = devm_request_mem_region(&pdev->dev, res->start,
resource_size(res), dev_name(&pdev->dev));
if (!res) {
dev_err(&pdev->dev, "failed to request STP memory\n");
return -EBUSY;
}
ltq_stp_membase = devm_ioremap_nocache(&pdev->dev, res->start,
resource_size(res));
if (!ltq_stp_membase) {
dev_err(&pdev->dev, "failed to remap STP memory\n");
return -ENOMEM;
}
ret = gpiochip_add(&ltq_stp_chip);
if (!ret)
ret = ltq_stp_hw_init();
return ret;
}
static struct platform_driver ltq_stp_driver = {
.probe = ltq_stp_probe,
.driver = {
.name = "ltq_stp",
.owner = THIS_MODULE,
},
};
int __init ltq_stp_init(void)
{
int ret = platform_driver_register(&ltq_stp_driver);
if (ret)
pr_info("ltq_stp: error registering platfom driver");
return ret;
}
postcore_initcall(ltq_stp_init);