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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-29 18:27:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-29 18:27:19 -0700
commit7e5b2db77b05746613516599c916a8cc2e321077 (patch)
treec3ec333ff7b77bcc8e456a3a3d19bf20f5c651b8 /drivers/gpio/gpio-mm-lantiq.c
parent227d1e4319ffd8729781941d92f4ae4d85beecd9 (diff)
parentc819baf31f5f91fbb06b2c93de2d5b8c8d096f3f (diff)
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle: "The whole series has been sitting in -next for quite a while with no complaints. The last change to the series was before the weekend the removal of an SPI patch which Grant - even though previously acked by himself - appeared to raise objections. So I removed it until the situation is clarified. Other than that all the patches have the acks from their respective maintainers, all MIPS and x86 defconfigs are building fine and I'm not aware of any problems introduced by this series. Among the key features for this patch series is a sizable patchset for Lantiq which among other things introduces support for Lantiq's flagship product, the FALCON SOC. It also means that the opensource developers behind this patchset have overtaken Lantiq's competing inhouse development team that was working behind closed doors. Less noteworthy the ath79 patchset which adds support for a few more chip variants, cleanups and fixes. Finally the usual dose of tweaking of generic code." Fix up trivial conflicts in arch/mips/lantiq/xway/gpio_{ebu,stp}.c where printk spelling fixes clashed with file move and eventual removal of the printk. * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (81 commits) MIPS: lantiq: remove orphaned code MIPS: Remove all -Wall and almost all -Werror usage from arch/mips. MIPS: lantiq: implement support for FALCON soc MTD: MIPS: lantiq: verify that the NOR interface is available on falcon soc MTD: MIPS: lantiq: implement OF support watchdog: MIPS: lantiq: implement OF support and minor fixes SERIAL: MIPS: lantiq: implement OF support GPIO: MIPS: lantiq: convert gpio-stp-xway to OF GPIO: MIPS: lantiq: convert gpio-mm-lantiq to OF and of_mm_gpio GPIO: MIPS: lantiq: move gpio-stp and gpio-ebu to the subsystem folder MIPS: pci: convert lantiq driver to OF MIPS: lantiq: convert dma to platform driver MIPS: lantiq: implement support for clkdev api MIPS: lantiq: drop ltq_gpio_request() and gpio_to_irq() OF: MIPS: lantiq: implement irq_domain support OF: MIPS: lantiq: implement OF support MIPS: lantiq: drop mips_machine support OF: PCI: const usage needed by MIPS MIPS: Cavium: Remove smp_reserve_lock. MIPS: Move cache setup to setup_arch(). ...
Diffstat (limited to 'drivers/gpio/gpio-mm-lantiq.c')
-rw-r--r--drivers/gpio/gpio-mm-lantiq.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-mm-lantiq.c b/drivers/gpio/gpio-mm-lantiq.c
new file mode 100644
index 00000000000..2983dfbd066
--- /dev/null
+++ b/drivers/gpio/gpio-mm-lantiq.c
@@ -0,0 +1,158 @@
+/*
+ * 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) 2012 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/of.h>
+#include <linux/of_gpio.h>
+#include <linux/io.h>
+#include <linux/slab.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 */
+
+struct ltq_mm {
+ struct of_mm_gpio_chip mmchip;
+ u16 shadow; /* shadow the latches state */
+};
+
+/**
+ * ltq_mm_apply() - write the shadow value to the ebu address.
+ * @chip: Pointer to our private data structure.
+ *
+ * Write the shadow value to the EBU to set the gpios. We need to set the
+ * global EBU lock to make sure that PCI/MTD dont break.
+ */
+static void ltq_mm_apply(struct ltq_mm *chip)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&ebu_lock, flags);
+ ltq_ebu_w32(LTQ_EBU_BUSCON, LTQ_EBU_BUSCON1);
+ __raw_writew(chip->shadow, chip->mmchip.regs);
+ ltq_ebu_w32(LTQ_EBU_BUSCON | LTQ_EBU_WP, LTQ_EBU_BUSCON1);
+ spin_unlock_irqrestore(&ebu_lock, flags);
+}
+
+/**
+ * ltq_mm_set() - gpio_chip->set - set gpios.
+ * @gc: Pointer to gpio_chip device structure.
+ * @gpio: GPIO signal number.
+ * @val: Value to be written to specified signal.
+ *
+ * Set the shadow value and call ltq_mm_apply.
+ */
+static void ltq_mm_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ltq_mm *chip =
+ container_of(mm_gc, struct ltq_mm, mmchip);
+
+ if (value)
+ chip->shadow |= (1 << offset);
+ else
+ chip->shadow &= ~(1 << offset);
+ ltq_mm_apply(chip);
+}
+
+/**
+ * ltq_mm_dir_out() - gpio_chip->dir_out - set gpio direction.
+ * @gc: Pointer to gpio_chip device structure.
+ * @gpio: GPIO signal number.
+ * @val: Value to be written to specified signal.
+ *
+ * Same as ltq_mm_set, always returns 0.
+ */
+static int ltq_mm_dir_out(struct gpio_chip *gc, unsigned offset, int value)
+{
+ ltq_mm_set(gc, offset, value);
+
+ return 0;
+}
+
+/**
+ * ltq_mm_save_regs() - Set initial values of GPIO pins
+ * @mm_gc: pointer to memory mapped GPIO chip structure
+ */
+static void ltq_mm_save_regs(struct of_mm_gpio_chip *mm_gc)
+{
+ struct ltq_mm *chip =
+ container_of(mm_gc, struct ltq_mm, mmchip);
+
+ /* tell the ebu controller which memory address we will be using */
+ ltq_ebu_w32(CPHYSADDR(chip->mmchip.regs) | 0x1, LTQ_EBU_ADDRSEL1);
+
+ ltq_mm_apply(chip);
+}
+
+static int ltq_mm_probe(struct platform_device *pdev)
+{
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ struct ltq_mm *chip;
+ const __be32 *shadow;
+ int ret = 0;
+
+ if (!res) {
+ dev_err(&pdev->dev, "failed to get memory resource\n");
+ return -ENOENT;
+ }
+
+ chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->mmchip.gc.ngpio = 16;
+ chip->mmchip.gc.label = "gpio-mm-ltq";
+ chip->mmchip.gc.direction_output = ltq_mm_dir_out;
+ chip->mmchip.gc.set = ltq_mm_set;
+ chip->mmchip.save_regs = ltq_mm_save_regs;
+
+ /* store the shadow value if one was passed by the devicetree */
+ shadow = of_get_property(pdev->dev.of_node, "lantiq,shadow", NULL);
+ if (shadow)
+ chip->shadow = be32_to_cpu(*shadow);
+
+ ret = of_mm_gpiochip_add(pdev->dev.of_node, &chip->mmchip);
+ if (ret)
+ kfree(chip);
+ return ret;
+}
+
+static const struct of_device_id ltq_mm_match[] = {
+ { .compatible = "lantiq,gpio-mm" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, ltq_mm_match);
+
+static struct platform_driver ltq_mm_driver = {
+ .probe = ltq_mm_probe,
+ .driver = {
+ .name = "gpio-mm-ltq",
+ .owner = THIS_MODULE,
+ .of_match_table = ltq_mm_match,
+ },
+};
+
+static int __init ltq_mm_init(void)
+{
+ return platform_driver_register(&ltq_mm_driver);
+}
+
+subsys_initcall(ltq_mm_init);