[PATCH 4/7] nomadik-gpio: add pin configuration API
Rabin Vincent
rabin.vincent at stericsson.com
Mon May 24 09:27:16 EDT 2010
Add a pin configuration API to all pin-related configuration to be
specified with a single macro and groups of pins to be configured
at one go. Based on the PXA MFP implementation.
Cc: Alessandro Rubini <rubini at unipv.it>
Acked-by: Linus Walleij <linus.walleij at stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent at stericsson.com>
---
arch/arm/plat-nomadik/gpio.c | 96 +++++++++++++++++++++++++++
arch/arm/plat-nomadik/include/plat/pincfg.h | 72 ++++++++++++++++++++
2 files changed, 168 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/plat-nomadik/include/plat/pincfg.h
diff --git a/arch/arm/plat-nomadik/gpio.c b/arch/arm/plat-nomadik/gpio.c
index 286ab42..983a2e8 100644
--- a/arch/arm/plat-nomadik/gpio.c
+++ b/arch/arm/plat-nomadik/gpio.c
@@ -23,6 +23,7 @@
#include <linux/irq.h>
#include <linux/slab.h>
+#include <plat/pincfg.h>
#include <mach/hardware.h>
#include <mach/gpio.h>
@@ -95,6 +96,101 @@ static void __nmk_gpio_set_pull(struct nmk_gpio_chip *nmk_chip,
writel(bit, nmk_chip->addr + NMK_GPIO_DATC);
}
+static void __nmk_gpio_make_input(struct nmk_gpio_chip *nmk_chip,
+ unsigned offset)
+{
+ writel(1 << offset, nmk_chip->addr + NMK_GPIO_DIRC);
+}
+
+static void __nmk_config_pin(struct nmk_gpio_chip *nmk_chip, unsigned offset,
+ pin_cfg_t cfg)
+{
+ static const char *afnames[] = {
+ [NMK_GPIO_ALT_GPIO] = "GPIO",
+ [NMK_GPIO_ALT_A] = "A",
+ [NMK_GPIO_ALT_B] = "B",
+ [NMK_GPIO_ALT_C] = "C"
+ };
+ static const char *pullnames[] = {
+ [NMK_GPIO_PULL_NONE] = "none",
+ [NMK_GPIO_PULL_UP] = "up",
+ [NMK_GPIO_PULL_DOWN] = "down",
+ [3] /* illegal */ = "??"
+ };
+ static const char *slpmnames[] = {
+ [NMK_GPIO_SLPM_INPUT] = "input",
+ [NMK_GPIO_SLPM_NOCHANGE] = "no-change",
+ };
+
+ int pin = PIN_NUM(cfg);
+ int pull = PIN_PULL(cfg);
+ int af = PIN_ALT(cfg);
+ int slpm = PIN_SLPM(cfg);
+
+ dev_dbg(nmk_chip->chip.dev, "pin %d: af %s, pull %s, slpm %s\n",
+ pin, afnames[af], pullnames[pull], slpmnames[slpm]);
+
+ __nmk_gpio_make_input(nmk_chip, offset);
+ __nmk_gpio_set_pull(nmk_chip, offset, pull);
+ __nmk_gpio_set_slpm(nmk_chip, offset, slpm);
+ __nmk_gpio_set_mode(nmk_chip, offset, af);
+}
+
+/**
+ * nmk_config_pin - configure a pin's mux attributes
+ * @cfg: pin confguration
+ *
+ * Configures a pin's mode (alternate function or GPIO), its pull up status,
+ * and its sleep mode based on the specified configuration. The @cfg is
+ * usually one of the SoC specific macros defined in mach/<soc>-pins.h. These
+ * are constructed using, and can be further enhanced with, the macros in
+ * plat/pincfg.h.
+ *
+ * If a pin's mode is set to GPIO, it is configured as an input to avoid
+ * side-effects. The gpio can be manipulated later using standard GPIO API
+ * calls.
+ */
+int nmk_config_pin(pin_cfg_t cfg)
+{
+ struct nmk_gpio_chip *nmk_chip;
+ int gpio = PIN_NUM(cfg);
+ unsigned long flags;
+
+ nmk_chip = get_irq_chip_data(NOMADIK_GPIO_TO_IRQ(gpio));
+ if (!nmk_chip)
+ return -EINVAL;
+
+ spin_lock_irqsave(&nmk_chip->lock, flags);
+ __nmk_config_pin(nmk_chip, gpio - nmk_chip->chip.base, cfg);
+ spin_unlock_irqrestore(&nmk_chip->lock, flags);
+
+ return 0;
+}
+EXPORT_SYMBOL(nmk_config_pin);
+
+/**
+ * nmk_config_pins - configure several pins at once
+ * @cfgs: array of pin configurations
+ * @num: number of elments in the array
+ *
+ * Configures several pins using nmk_config_pin(). Refer to that function for
+ * further information.
+ */
+int nmk_config_pins(pin_cfg_t *cfgs, int num)
+{
+ int ret = 0;
+ int i;
+
+ for (i = 0; i < num; i++) {
+ int ret = nmk_config_pin(cfgs[i]);
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL(nmk_config_pins);
+
/**
* nmk_gpio_set_slpm() - configure the sleep mode of a pin
* @gpio: pin number
diff --git a/arch/arm/plat-nomadik/include/plat/pincfg.h b/arch/arm/plat-nomadik/include/plat/pincfg.h
new file mode 100644
index 0000000..7eed11c
--- /dev/null
+++ b/arch/arm/plat-nomadik/include/plat/pincfg.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License terms: GNU General Public License, version 2
+ * Author: Rabin Vincent <rabin.vincent at stericsson.com> for ST-Ericsson
+ *
+ * Based on arch/arm/mach-pxa/include/mach/mfp.h:
+ * Copyright (C) 2007 Marvell International Ltd.
+ * eric miao <eric.miao at marvell.com>
+ */
+
+#ifndef __PLAT_PINCFG_H
+#define __PLAT_PINCFG_H
+
+/*
+ * pin configurations are represented by 32-bit integers:
+ *
+ * bit 0.. 8 - Pin Number (512 Pins Maximum)
+ * bit 9..10 - Alternate Function Selection
+ * bit 11..12 - Pull up/down state
+ * bit 13 - Sleep mode behaviour
+ *
+ * to facilitate the definition, the following macros are provided
+ *
+ * PIN_CFG_DEFAULT - default config (0):
+ * pull up/down = disabled
+ * sleep mode = input
+ *
+ * PIN_CFG - default config with alternate function
+ * PIN_CFG_PULL - default config with alternate function and pull up/down
+ */
+
+typedef unsigned long pin_cfg_t;
+
+#define PIN_NUM_MASK 0x1ff
+#define PIN_NUM(x) ((x) & PIN_NUM_MASK)
+
+#define PIN_ALT_SHIFT 9
+#define PIN_ALT_MASK (0x3 << PIN_ALT_SHIFT)
+#define PIN_ALT(x) (((x) & PIN_ALT_MASK) >> PIN_ALT_SHIFT)
+#define PIN_GPIO (NMK_GPIO_ALT_GPIO << PIN_ALT_SHIFT)
+#define PIN_ALT_A (NMK_GPIO_ALT_A << PIN_ALT_SHIFT)
+#define PIN_ALT_B (NMK_GPIO_ALT_B << PIN_ALT_SHIFT)
+#define PIN_ALT_C (NMK_GPIO_ALT_C << PIN_ALT_SHIFT)
+
+#define PIN_PULL_SHIFT 11
+#define PIN_PULL_MASK (0x3 << PIN_PULL_SHIFT)
+#define PIN_PULL(x) (((x) & PIN_PULL_MASK) >> PIN_PULL_SHIFT)
+#define PIN_PULL_NONE (NMK_GPIO_PULL_NONE << PIN_PULL_SHIFT)
+#define PIN_PULL_UP (NMK_GPIO_PULL_UP << PIN_PULL_SHIFT)
+#define PIN_PULL_DOWN (NMK_GPIO_PULL_DOWN << PIN_PULL_SHIFT)
+
+#define PIN_SLPM_SHIFT 13
+#define PIN_SLPM_MASK (0x1 << PIN_SLPM_SHIFT)
+#define PIN_SLPM(x) (((x) & PIN_SLPM_MASK) >> PIN_SLPM_SHIFT)
+#define PIN_SLPM_INPUT (NMK_GPIO_SLPM_INPUT << PIN_SLPM_SHIFT)
+#define PIN_SLPM_NOCHANGE (NMK_GPIO_SLPM_NOCHANGE << PIN_SLPM_SHIFT)
+
+#define PIN_CFG_DEFAULT (PIN_PULL_NONE | PIN_SLPM_INPUT)
+
+#define PIN_CFG(num, alt) \
+ (PIN_CFG_DEFAULT |\
+ (PIN_NUM(num) | PIN_##alt))
+
+#define PIN_CFG_PULL(num, alt, pull) \
+ ((PIN_CFG_DEFAULT & ~PIN_PULL_MASK) |\
+ (PIN_NUM(num) | PIN_##alt | PIN_PULL_##pull))
+
+extern int nmk_config_pin(pin_cfg_t cfg);
+extern int nmk_config_pins(pin_cfg_t *cfgs, int num);
+
+#endif
--
1.7.0
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