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>

1 files changed, 157 insertions, 0 deletions

diff --git a/arch/mips/lantiq/xway/gpio_stp.c b/arch/mips/lantiq/xway/gpio_stp.c
new file mode 100644
index 00000000000..67d59d69034
--- /dev/null
+++ b/arch/mips/lantiq/xway/gpio_stp.c
@@ -0,0 +1,157 @@
+/*
+ *  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);