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>

6 files changed, 128 insertions, 0 deletions

diff --git a/drivers/bcma/Kconfig b/drivers/bcma/Kconfig
index a533af218368..d7b56a88c9f4 100644
--- a/drivers/bcma/Kconfig
+++ b/drivers/bcma/Kconfig
@@ -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
diff --git a/drivers/bcma/Makefile b/drivers/bcma/Makefile
index 8ad42d41b2f2..734b32f09c0a 100644
--- a/drivers/bcma/Makefile
+++ b/drivers/bcma/Makefile
@@ -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
diff --git a/drivers/bcma/bcma_private.h b/drivers/bcma/bcma_private.h
index 169fc58427d3..8cd80bff8e91 100644
--- a/drivers/bcma/bcma_private.h
+++ b/drivers/bcma/bcma_private.h
@@ -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
diff --git a/drivers/bcma/driver_gpio.c b/drivers/bcma/driver_gpio.c
new file mode 100644
index 000000000000..9a6f585da2d9
--- /dev/null
+++ b/drivers/bcma/driver_gpio.c
@@ -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);
+}
diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c
index d865470bc951..478ba01ca0c2 100644
--- a/drivers/bcma/main.c
+++ b/drivers/bcma/main.c
@@ -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;
 }
diff --git a/include/linux/bcma/bcma_driver_chipcommon.h b/include/linux/bcma/bcma_driver_chipcommon.h
index 256702663b68..7d662a988d24 100644
--- a/include/linux/bcma/bcma_driver_chipcommon.h
+++ b/include/linux/bcma/bcma_driver_chipcommon.h
@@ -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 */