ssb: 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/4591
Acked-by: Florian Fainelli <florian@openwrt.org>

diff --git a/drivers/ssb/Kconfig b/drivers/ssb/Kconfig
index 42cdaa9..ff3c8a2 100644 (file)
--- a/drivers/ssb/Kconfig
+++ b/drivers/ssb/Kconfig
@@ -160,4 +160,13 @@ config SSB_DRIVER_GIGE
 
          If unsure, say N
 
+config SSB_DRIVER_GPIO
+       bool "SSB GPIO driver"
+       depends on SSB
+       select GPIOLIB
+       help
+         Driver to provide access to the GPIO pins on the bus.
+
+         If unsure, say N
+
 endmenu

diff --git a/drivers/ssb/Makefile b/drivers/ssb/Makefile
index 656e58b..9159ba7 100644 (file)
--- a/drivers/ssb/Makefile
+++ b/drivers/ssb/Makefile
@@ -15,6 +15,7 @@ ssb-$(CONFIG_SSB_DRIVER_MIPS)         += driver_mipscore.o
 ssb-$(CONFIG_SSB_DRIVER_EXTIF)         += driver_extif.o
 ssb-$(CONFIG_SSB_DRIVER_PCICORE)       += driver_pcicore.o
 ssb-$(CONFIG_SSB_DRIVER_GIGE)          += driver_gige.o
+ssb-$(CONFIG_SSB_DRIVER_GPIO)          += driver_gpio.o
 
 # b43 pci-ssb-bridge driver
 # Not strictly a part of SSB, but kept here for convenience

diff --git a/drivers/ssb/driver_gpio.c b/drivers/ssb/driver_gpio.c
new file mode 100644 (file)
index 0000000..97ac0a3
--- /dev/null
+++ b/drivers/ssb/driver_gpio.c
@@ -0,0 +1,176 @@
+/*
+ * Sonics Silicon Backplane
+ * 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/ssb/ssb.h>
+
+#include "ssb_private.h"
+
+static struct ssb_bus *ssb_gpio_get_bus(struct gpio_chip *chip)
+{
+       return container_of(chip, struct ssb_bus, gpio);
+}
+
+static int ssb_gpio_chipco_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       return !!ssb_chipco_gpio_in(&bus->chipco, 1 << gpio);
+}
+
+static void ssb_gpio_chipco_set_value(struct gpio_chip *chip, unsigned gpio,
+                                     int value)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       ssb_chipco_gpio_out(&bus->chipco, 1 << gpio, value ? 1 << gpio : 0);
+}
+
+static int ssb_gpio_chipco_direction_input(struct gpio_chip *chip,
+                                          unsigned gpio)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       ssb_chipco_gpio_outen(&bus->chipco, 1 << gpio, 0);
+       return 0;
+}
+
+static int ssb_gpio_chipco_direction_output(struct gpio_chip *chip,
+                                           unsigned gpio, int value)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       ssb_chipco_gpio_outen(&bus->chipco, 1 << gpio, 1 << gpio);
+       ssb_chipco_gpio_out(&bus->chipco, 1 << gpio, value ? 1 << gpio : 0);
+       return 0;
+}
+
+static int ssb_gpio_chipco_request(struct gpio_chip *chip, unsigned gpio)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       ssb_chipco_gpio_control(&bus->chipco, 1 << gpio, 0);
+       /* clear pulldown */
+       ssb_chipco_gpio_pulldown(&bus->chipco, 1 << gpio, 0);
+       /* Set pullup */
+       ssb_chipco_gpio_pullup(&bus->chipco, 1 << gpio, 1 << gpio);
+
+       return 0;
+}
+
+static void ssb_gpio_chipco_free(struct gpio_chip *chip, unsigned gpio)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       /* clear pullup */
+       ssb_chipco_gpio_pullup(&bus->chipco, 1 << gpio, 0);
+}
+
+static int ssb_gpio_chipco_init(struct ssb_bus *bus)
+{
+       struct gpio_chip *chip = &bus->gpio;
+
+       chip->label             = "ssb_chipco_gpio";
+       chip->owner             = THIS_MODULE;
+       chip->request           = ssb_gpio_chipco_request;
+       chip->free              = ssb_gpio_chipco_free;
+       chip->get               = ssb_gpio_chipco_get_value;
+       chip->set               = ssb_gpio_chipco_set_value;
+       chip->direction_input   = ssb_gpio_chipco_direction_input;
+       chip->direction_output  = ssb_gpio_chipco_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 (bus->bustype == SSB_BUSTYPE_SSB)
+               chip->base              = 0;
+       else
+               chip->base              = -1;
+
+       return gpiochip_add(chip);
+}
+
+#ifdef CONFIG_SSB_DRIVER_EXTIF
+
+static int ssb_gpio_extif_get_value(struct gpio_chip *chip, unsigned gpio)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       return !!ssb_extif_gpio_in(&bus->extif, 1 << gpio);
+}
+
+static void ssb_gpio_extif_set_value(struct gpio_chip *chip, unsigned gpio,
+                                    int value)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       ssb_extif_gpio_out(&bus->extif, 1 << gpio, value ? 1 << gpio : 0);
+}
+
+static int ssb_gpio_extif_direction_input(struct gpio_chip *chip,
+                                         unsigned gpio)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       ssb_extif_gpio_outen(&bus->extif, 1 << gpio, 0);
+       return 0;
+}
+
+static int ssb_gpio_extif_direction_output(struct gpio_chip *chip,
+                                          unsigned gpio, int value)
+{
+       struct ssb_bus *bus = ssb_gpio_get_bus(chip);
+
+       ssb_extif_gpio_outen(&bus->extif, 1 << gpio, 1 << gpio);
+       ssb_extif_gpio_out(&bus->extif, 1 << gpio, value ? 1 << gpio : 0);
+       return 0;
+}
+
+static int ssb_gpio_extif_init(struct ssb_bus *bus)
+{
+       struct gpio_chip *chip = &bus->gpio;
+
+       chip->label             = "ssb_extif_gpio";
+       chip->owner             = THIS_MODULE;
+       chip->get               = ssb_gpio_extif_get_value;
+       chip->set               = ssb_gpio_extif_set_value;
+       chip->direction_input   = ssb_gpio_extif_direction_input;
+       chip->direction_output  = ssb_gpio_extif_direction_output;
+       chip->ngpio             = 5;
+       /* 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 (bus->bustype == SSB_BUSTYPE_SSB)
+               chip->base              = 0;
+       else
+               chip->base              = -1;
+
+       return gpiochip_add(chip);
+}
+
+#else
+static int ssb_gpio_extif_init(struct ssb_bus *bus)
+{
+       return -ENOTSUPP;
+}
+#endif
+
+int ssb_gpio_init(struct ssb_bus *bus)
+{
+       if (ssb_chipco_available(&bus->chipco))
+               return ssb_gpio_chipco_init(bus);
+       else if (ssb_extif_available(&bus->extif))
+               return ssb_gpio_extif_init(bus);
+       else
+               SSB_WARN_ON(1);
+
+       return -1;
+}

diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
index 6fe2d10..87f0ddf 100644 (file)
--- a/drivers/ssb/main.c
+++ b/drivers/ssb/main.c
@@ -798,6 +798,12 @@ static int __devinit ssb_bus_register(struct ssb_bus *bus,
        ssb_chipcommon_init(&bus->chipco);
        ssb_extif_init(&bus->extif);
        ssb_mipscore_init(&bus->mipscore);
+       err = ssb_gpio_init(bus);
+       if (err == -ENOTSUPP)
+               ssb_dprintk(KERN_DEBUG PFX "GPIO driver not activated\n");
+       else if (err)
+               ssb_dprintk(KERN_ERR PFX
+                          "Error registering GPIO driver: %i\n", err);
        err = ssb_fetch_invariants(bus, get_invariants);
        if (err) {
                ssb_bus_may_powerdown(bus);

diff --git a/drivers/ssb/ssb_private.h b/drivers/ssb/ssb_private.h
index d6a1ba9..463b76a 100644 (file)
--- a/drivers/ssb/ssb_private.h
+++ b/drivers/ssb/ssb_private.h
@@ -219,4 +219,13 @@ static inline void ssb_extif_init(struct ssb_extif *extif)
 }
 #endif
 
+#ifdef CONFIG_SSB_DRIVER_GPIO
+extern int ssb_gpio_init(struct ssb_bus *bus);
+#else /* CONFIG_SSB_DRIVER_GPIO */
+static inline int ssb_gpio_init(struct ssb_bus *bus)
+{
+       return -ENOTSUPP;
+}
+#endif /* CONFIG_SSB_DRIVER_GPIO */
+
 #endif /* LINUX_SSB_PRIVATE_H_ */

diff --git a/include/linux/ssb/ssb.h b/include/linux/ssb/ssb.h
index bb674c0..3862a5b 100644 (file)
--- a/include/linux/ssb/ssb.h
+++ b/include/linux/ssb/ssb.h
@@ -6,6 +6,7 @@
 #include <linux/types.h>
 #include <linux/spinlock.h>
 #include <linux/pci.h>
+#include <linux/gpio.h>
 #include <linux/mod_devicetable.h>
 #include <linux/dma-mapping.h>
 
@@ -433,6 +434,9 @@ struct ssb_bus {
        /* Lock for GPIO register access. */
        spinlock_t gpio_lock;
 #endif /* EMBEDDED */
+#ifdef CONFIG_SSB_DRIVER_GPIO
+       struct gpio_chip gpio;
+#endif /* DRIVER_GPIO */
 
        /* Internal-only stuff follows. Do not touch. */
        struct list_head list;