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bcma: add GPIO driver

Register a GPIO driver to access the GPIOs provided by the chip.
The GPIOs of the SoC should always start at 0 and the other GPIOs could
start at a random position. There is just one SoC in a system and when
they start at 0 the number is predictable.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Patchwork: http://patchwork.linux-mips.org/patch/4587
Acked-by: Florian Fainelli <florian@openwrt.org>
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1 parent 3e8bb50 commit cf0936b06d8e98a157630e99f647e2ff6d29d7ad @hauke hauke committed with John Crispin Nov 20, 2012
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@@ -65,6 +65,15 @@ config BCMA_DRIVER_GMAC_CMN
If unsure, say N
+config BCMA_DRIVER_GPIO
+ bool "BCMA GPIO driver"
+ depends on BCMA
+ select GPIOLIB
+ help
+ Driver to provide access to the GPIO pins of the bcma bus.
+
+ If unsure, say N
+
config BCMA_DEBUG
bool "BCMA debugging"
depends on BCMA
View
@@ -6,6 +6,7 @@ bcma-y += driver_pci.o
bcma-$(CONFIG_BCMA_DRIVER_PCI_HOSTMODE) += driver_pci_host.o
bcma-$(CONFIG_BCMA_DRIVER_MIPS) += driver_mips.o
bcma-$(CONFIG_BCMA_DRIVER_GMAC_CMN) += driver_gmac_cmn.o
+bcma-$(CONFIG_BCMA_DRIVER_GPIO) += driver_gpio.o
bcma-$(CONFIG_BCMA_HOST_PCI) += host_pci.o
bcma-$(CONFIG_BCMA_HOST_SOC) += host_soc.o
obj-$(CONFIG_BCMA) += bcma.o
@@ -89,4 +89,14 @@ bool __devinit bcma_core_pci_is_in_hostmode(struct bcma_drv_pci *pc);
void __devinit bcma_core_pci_hostmode_init(struct bcma_drv_pci *pc);
#endif /* CONFIG_BCMA_DRIVER_PCI_HOSTMODE */
+#ifdef CONFIG_BCMA_DRIVER_GPIO
+/* driver_gpio.c */
+int bcma_gpio_init(struct bcma_drv_cc *cc);
+#else
+static inline int bcma_gpio_init(struct bcma_drv_cc *cc)
+{
+ return -ENOTSUPP;
+}
+#endif /* CONFIG_BCMA_DRIVER_GPIO */
+
#endif
View
@@ -0,0 +1,98 @@
+/*
+ * Broadcom specific AMBA
+ * GPIO driver
+ *
+ * Copyright 2011, Broadcom Corporation
+ * Copyright 2012, Hauke Mehrtens <hauke@hauke-m.de>
+ *
+ * Licensed under the GNU/GPL. See COPYING for details.
+ */
+
+#include <linux/gpio.h>
+#include <linux/export.h>
+#include <linux/bcma/bcma.h>
+
+#include "bcma_private.h"
+
+static inline struct bcma_drv_cc *bcma_gpio_get_cc(struct gpio_chip *chip)
+{
+ return container_of(chip, struct bcma_drv_cc, gpio);
+}
+
+static int bcma_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+ struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
+
+ return !!bcma_chipco_gpio_in(cc, 1 << gpio);
+}
+
+static void bcma_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
+ int value)
+{
+ struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
+
+ bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
+}
+
+static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
+{
+ struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
+
+ bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
+ return 0;
+}
+
+static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
+ int value)
+{
+ struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
+
+ bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
+ bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
+ return 0;
+}
+
+static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
+{
+ struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
+
+ bcma_chipco_gpio_control(cc, 1 << gpio, 0);
+ /* clear pulldown */
+ bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
+ /* Set pullup */
+ bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
+
+ return 0;
+}
+
+static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
+{
+ struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
+
+ /* clear pullup */
+ bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
+}
+
+int bcma_gpio_init(struct bcma_drv_cc *cc)
+{
+ struct gpio_chip *chip = &cc->gpio;
+
+ chip->label = "bcma_gpio";
+ chip->owner = THIS_MODULE;
+ chip->request = bcma_gpio_request;
+ chip->free = bcma_gpio_free;
+ chip->get = bcma_gpio_get_value;
+ chip->set = bcma_gpio_set_value;
+ chip->direction_input = bcma_gpio_direction_input;
+ chip->direction_output = bcma_gpio_direction_output;
+ chip->ngpio = 16;
+ /* There is just one SoC in one device and its GPIO addresses should be
+ * deterministic to address them more easily. The other buses could get
+ * a random base number. */
+ if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
+ chip->base = 0;
+ else
+ chip->base = -1;
+
+ return gpiochip_add(chip);
+}
View
@@ -152,6 +152,11 @@ static int bcma_register_cores(struct bcma_bus *bus)
bcma_err(bus, "Error registering NAND flash\n");
}
#endif
+ err = bcma_gpio_init(&bus->drv_cc);
+ if (err == -ENOTSUPP)
+ bcma_debug(bus, "GPIO driver not activated\n");
+ else if (err)
+ bcma_err(bus, "Error registering GPIO driver: %i\n", err);
return 0;
}
@@ -1,6 +1,8 @@
#ifndef LINUX_BCMA_DRIVER_CC_H_
#define LINUX_BCMA_DRIVER_CC_H_
+#include <linux/gpio.h>
+
/** ChipCommon core registers. **/
#define BCMA_CC_ID 0x0000
#define BCMA_CC_ID_ID 0x0000FFFF
@@ -570,6 +572,9 @@ struct bcma_drv_cc {
/* Lock for GPIO register access. */
spinlock_t gpio_lock;
+#ifdef CONFIG_BCMA_DRIVER_GPIO
+ struct gpio_chip gpio;
+#endif
};
/* Register access */

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