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Diffstat (limited to 'arch/powerpc/platforms/4xx/gpio.c')
-rw-r--r--arch/powerpc/platforms/4xx/gpio.c195
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/4xx/gpio.c b/arch/powerpc/platforms/4xx/gpio.c
new file mode 100644
index 000000000..49ee8d365
--- /dev/null
+++ b/arch/powerpc/platforms/4xx/gpio.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * PPC4xx gpio driver
+ *
+ * Copyright (c) 2008 Harris Corporation
+ * Copyright (c) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
+ * Copyright (c) MontaVista Software, Inc. 2008.
+ *
+ * Author: Steve Falco <sfalco@harris.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/gpio/driver.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+
+#define GPIO_MASK(gpio) (0x80000000 >> (gpio))
+#define GPIO_MASK2(gpio) (0xc0000000 >> ((gpio) * 2))
+
+/* Physical GPIO register layout */
+struct ppc4xx_gpio {
+ __be32 or;
+ __be32 tcr;
+ __be32 osrl;
+ __be32 osrh;
+ __be32 tsrl;
+ __be32 tsrh;
+ __be32 odr;
+ __be32 ir;
+ __be32 rr1;
+ __be32 rr2;
+ __be32 rr3;
+ __be32 reserved1;
+ __be32 isr1l;
+ __be32 isr1h;
+ __be32 isr2l;
+ __be32 isr2h;
+ __be32 isr3l;
+ __be32 isr3h;
+};
+
+struct ppc4xx_gpio_chip {
+ struct of_mm_gpio_chip mm_gc;
+ spinlock_t lock;
+};
+
+/*
+ * GPIO LIB API implementation for GPIOs
+ *
+ * There are a maximum of 32 gpios in each gpio controller.
+ */
+
+static int ppc4xx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+
+ return !!(in_be32(&regs->ir) & GPIO_MASK(gpio));
+}
+
+static inline void
+__ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+
+ if (val)
+ setbits32(&regs->or, GPIO_MASK(gpio));
+ else
+ clrbits32(&regs->or, GPIO_MASK(gpio));
+}
+
+static void
+ppc4xx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+
+ __ppc4xx_gpio_set(gc, gpio, val);
+
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
+}
+
+static int ppc4xx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+
+ /* Disable open-drain function */
+ clrbits32(&regs->odr, GPIO_MASK(gpio));
+
+ /* Float the pin */
+ clrbits32(&regs->tcr, GPIO_MASK(gpio));
+
+ /* Bits 0-15 use TSRL/OSRL, bits 16-31 use TSRH/OSRH */
+ if (gpio < 16) {
+ clrbits32(&regs->osrl, GPIO_MASK2(gpio));
+ clrbits32(&regs->tsrl, GPIO_MASK2(gpio));
+ } else {
+ clrbits32(&regs->osrh, GPIO_MASK2(gpio));
+ clrbits32(&regs->tsrh, GPIO_MASK2(gpio));
+ }
+
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ return 0;
+}
+
+static int
+ppc4xx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
+{
+ struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc);
+ struct ppc4xx_gpio_chip *chip = gpiochip_get_data(gc);
+ struct ppc4xx_gpio __iomem *regs = mm_gc->regs;
+ unsigned long flags;
+
+ spin_lock_irqsave(&chip->lock, flags);
+
+ /* First set initial value */
+ __ppc4xx_gpio_set(gc, gpio, val);
+
+ /* Disable open-drain function */
+ clrbits32(&regs->odr, GPIO_MASK(gpio));
+
+ /* Drive the pin */
+ setbits32(&regs->tcr, GPIO_MASK(gpio));
+
+ /* Bits 0-15 use TSRL, bits 16-31 use TSRH */
+ if (gpio < 16) {
+ clrbits32(&regs->osrl, GPIO_MASK2(gpio));
+ clrbits32(&regs->tsrl, GPIO_MASK2(gpio));
+ } else {
+ clrbits32(&regs->osrh, GPIO_MASK2(gpio));
+ clrbits32(&regs->tsrh, GPIO_MASK2(gpio));
+ }
+
+ spin_unlock_irqrestore(&chip->lock, flags);
+
+ pr_debug("%s: gpio: %d val: %d\n", __func__, gpio, val);
+
+ return 0;
+}
+
+static int __init ppc4xx_add_gpiochips(void)
+{
+ struct device_node *np;
+
+ for_each_compatible_node(np, NULL, "ibm,ppc4xx-gpio") {
+ int ret;
+ struct ppc4xx_gpio_chip *ppc4xx_gc;
+ struct of_mm_gpio_chip *mm_gc;
+ struct gpio_chip *gc;
+
+ ppc4xx_gc = kzalloc(sizeof(*ppc4xx_gc), GFP_KERNEL);
+ if (!ppc4xx_gc) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ spin_lock_init(&ppc4xx_gc->lock);
+
+ mm_gc = &ppc4xx_gc->mm_gc;
+ gc = &mm_gc->gc;
+
+ gc->ngpio = 32;
+ gc->direction_input = ppc4xx_gpio_dir_in;
+ gc->direction_output = ppc4xx_gpio_dir_out;
+ gc->get = ppc4xx_gpio_get;
+ gc->set = ppc4xx_gpio_set;
+
+ ret = of_mm_gpiochip_add_data(np, mm_gc, ppc4xx_gc);
+ if (ret)
+ goto err;
+ continue;
+err:
+ pr_err("%pOF: registration failed with status %d\n", np, ret);
+ kfree(ppc4xx_gc);
+ /* try others anyway */
+ }
+ return 0;
+}
+arch_initcall(ppc4xx_add_gpiochips);