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[PATCH V4 10/10] MIPS: lantiq: add more gpio drivers

To: Ralf Baechle <ralf@linux-mips.org>
Subject: [PATCH V4 10/10] MIPS: lantiq: add more gpio drivers
From: John Crispin <blogic@openwrt.org>
Date: Mon, 28 Mar 2011 16:07:57 +0200
Cc: John Crispin <blogic@openwrt.org>, Ralph Hempel <ralph.hempel@lantiq.com>, linux-mips@linux-mips.org
In-reply-to: <1301321277-6700-1-git-send-email-blogic@openwrt.org>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <1301321277-6700-1-git-send-email-blogic@openwrt.org>
Sender: linux-mips-bounce@linux-mips.org
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.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Ralph Hempel <ralph.hempel@lantiq.com>
Cc: linux-mips@linux-mips.org
---
Added in V2

Changes in V3
* whitespace
* change __iomem void to void __iomem
* multiline comments
* use pr_* macros instead of printk

Changes in V4
* whitespace fixes
* properly insert and request all memory ranges

 arch/mips/lantiq/xway/Makefile   |    2 +-
 arch/mips/lantiq/xway/gpio_ebu.c |  130 +++++++++++++++++++++++++++++++
 arch/mips/lantiq/xway/gpio_stp.c |  160 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 291 insertions(+), 1 deletions(-)
 create mode 100644 arch/mips/lantiq/xway/gpio_ebu.c
 create mode 100644 arch/mips/lantiq/xway/gpio_stp.c

diff --git a/arch/mips/lantiq/xway/Makefile b/arch/mips/lantiq/xway/Makefile
index 08dcc10..a021def 100644
--- a/arch/mips/lantiq/xway/Makefile
+++ b/arch/mips/lantiq/xway/Makefile
@@ -1,4 +1,4 @@
-obj-y := pmu.o ebu.o reset.o gpio.o devices.o
+obj-y := pmu.o ebu.o reset.o gpio.o gpio_stp.o gpio_ebu.o devices.o
 
 obj-$(CONFIG_SOC_XWAY) += clk-xway.o prom-xway.o
 obj-$(CONFIG_SOC_AMAZON_SE) += clk-ase.o prom-ase.o
diff --git a/arch/mips/lantiq/xway/gpio_ebu.c b/arch/mips/lantiq/xway/gpio_ebu.c
new file mode 100644
index 0000000..8ebc1a4
--- /dev/null
+++ b/arch/mips/lantiq/xway/gpio_ebu.c
@@ -0,0 +1,130 @@
+/*
+ *  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) 2010 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/gpio.h>
+#include <linux/io.h>
+
+#include <lantiq_soc.h>
+
+/* By attaching hardware latches to the EBU it is possible to create output
+ * only gpios. This driver configures a special memory address, which when
+ * written to outputs 16 bit to the latches.
+ */
+
+#define LTQ_EBU_BUSCON 0x1e7ff         /* 16 bit access, slowest timing */
+#define LTQ_EBU_WP     0x80000000      /* write protect bit */
+
+/* we keep a shadow value of the last value written to the ebu */
+static int ltq_ebu_gpio_shadow = 0x0;
+static void __iomem *ltq_ebu_gpio_membase;
+
+static void
+ltq_ebu_apply(void)
+{
+       unsigned long flags;
+
+       spin_lock_irqsave(&ebu_lock, flags);
+       ltq_ebu_w32(LTQ_EBU_BUSCON, LTQ_EBU_BUSCON1);
+       *((__u16 *)ltq_ebu_gpio_membase) = ltq_ebu_gpio_shadow;
+       ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);
+       spin_unlock_irqrestore(&ebu_lock, flags);
+}
+
+static void
+ltq_ebu_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+       if (value)
+               ltq_ebu_gpio_shadow |= (1 << offset);
+       else
+               ltq_ebu_gpio_shadow &= ~(1 << offset);
+       ltq_ebu_apply();
+}
+
+static int
+ltq_ebu_direction_output(struct gpio_chip *chip, unsigned offset, int value)
+{
+       ltq_ebu_set(chip, offset, value);
+       return 0;
+}
+
+static struct gpio_chip
+ltq_ebu_chip = {
+       .label = "ltq_ebu",
+       .direction_output = ltq_ebu_direction_output,
+       .set = ltq_ebu_set,
+       .base = 72,
+       .ngpio = 16,
+       .can_sleep = 1,
+       .owner = THIS_MODULE,
+};
+
+static int
+ltq_ebu_probe(struct platform_device *pdev)
+{
+       int ret = 0;
+       struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+       if (!res) {
+               dev_err(&pdev->dev, "failed to get memory resource\n");
+               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 memory resource\n");
+               return -EBUSY;
+       }
+
+       ltq_ebu_gpio_membase = devm_ioremap_nocache(&pdev->dev, res->start,
+               resource_size(res));
+       if (!ltq_ebu_gpio_membase) {
+               dev_err(&pdev->dev, "Failed to ioremap mem region\n");
+               return -ENOMEM;
+       }
+
+       /* grab the default shadow value passed form the platform code */
+       ltq_ebu_gpio_shadow = (unsigned int) pdev->dev.platform_data;
+
+       /* tell the ebu controller which memory address we will be using */
+       ltq_ebu_w32(pdev->resource->start | 0x1, LTQ_EBU_ADDRSEL1);
+
+       /* write protect the region */
+       ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);
+
+       ret = gpiochip_add(&ltq_ebu_chip);
+       if (!ret)
+               ltq_ebu_apply();
+       return ret;
+}
+
+static struct platform_driver
+ltq_ebu_driver = {
+       .probe = ltq_ebu_probe,
+       .driver = {
+               .name = "ltq_ebu",
+               .owner = THIS_MODULE,
+       },
+};
+
+static int __init
+ltq_ebu_init(void)
+{
+       int ret = platform_driver_register(&ltq_ebu_driver);
+
+       if (ret)
+               pr_info("ltq_ebu : Error registering platfom driver!");
+       return ret;
+}
+
+postcore_initcall(ltq_ebu_init);
diff --git a/arch/mips/lantiq/xway/gpio_stp.c b/arch/mips/lantiq/xway/gpio_stp.c
new file mode 100644
index 0000000..4bd7c3e
--- /dev/null
+++ b/arch/mips/lantiq/xway/gpio_stp.c
@@ -0,0 +1,160 @@
+/*
+ *  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 __init
+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);
-- 
1.7.2.3


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