msm: qpnp: Add gpiolib support for PMIC GPIOs

Add a gpio_chip driver to support the Qualcomm SPMI PMIC
architecture called QPNP. The driver supports Device Tree
and allows a device_node to be registered as a gpio-controller.

The driver also specifies APIs to allow a non-Device Tree user
the ability to configure the PMIC GPIOs.

This driver does not handle interrupts for GPIOs directly.
Instead, that work is handled by the existing qpnp-int driver.
This is feasible since the interrupt register map for all
QPNP peripherals is the same.

Change-Id: I04eb39d9855b0957f0647010fcb203ec2fc83c7c
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
diff --git a/include/linux/qpnp/gpio.h b/include/linux/qpnp/gpio.h
new file mode 100644
index 0000000..0447a08
--- /dev/null
+++ b/include/linux/qpnp/gpio.h
@@ -0,0 +1,114 @@
+/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <mach/qpnp.h>
+
+#define QPNP_GPIO_DIR_OUT			1
+#define QPNP_GPIO_DIR_IN			2
+#define QPNP_GPIO_DIR_BOTH	(QPNP_GPIO_DIR_OUT | QPNP_GPIO_DIR_IN)
+
+#define QPNP_GPIO_OUT_BUF_OPEN_DRAIN		1
+#define QPNP_GPIO_OUT_BUF_CMOS			0
+
+#define QPNP_GPIO_VIN0				0
+#define QPNP_GPIO_VIN1				1
+#define QPNP_GPIO_VIN2				2
+#define QPNP_GPIO_VIN3				3
+#define QPNP_GPIO_VIN4				4
+#define QPNP_GPIO_VIN5				5
+#define QPNP_GPIO_VIN6				6
+#define QPNP_GPIO_VIN7				7
+
+#define QPNP_GPIO_PULL_UP_30			0
+#define QPNP_GPIO_PULL_UP_1P5			1
+#define QPNP_GPIO_PULL_UP_31P5			2
+#define QPNP_GPIO_PULL_UP_1P5_30		3
+#define QPNP_GPIO_PULL_DN			4
+#define QPNP_GPIO_PULL_NO			5
+
+#define QPNP_GPIO_OUT_STRENGTH_LOW		1
+#define QPNP_GPIO_OUT_STRENGTH_MED		2
+#define QPNP_GPIO_OUT_STRENGTH_HIGH		3
+
+#define QPNP_GPIO_FUNC_NORMAL			0
+#define QPNP_GPIO_FUNC_PAIRED			1
+#define QPNP_GPIO_FUNC_1			2
+#define QPNP_GPIO_FUNC_2			3
+#define QPNP_GPIO_DTEST1			4
+#define QPNP_GPIO_DTEST2			5
+#define QPNP_GPIO_DTEST3			6
+#define QPNP_GPIO_DTEST4			7
+
+/**
+ * struct qpnp_gpio_cfg - structure to specify gpio configurtion values
+ * @direction:		indicates whether the gpio should be input, output, or
+ *			both. Should be of the type QPNP_GPIO_DIR_*
+ * @output_type:	indicates gpio should be configured as CMOS or open
+ *			drain. Should be of the type QPNP_GPIO_OUT_BUF_*
+ * @output_value:	The gpio output value of the gpio line - 0 or 1
+ * @pull:		Indicates whether a pull up or pull down should be
+ *			applied. If a pullup is required the current strength
+ *			needs to be specified. Current values of 30uA, 1.5uA,
+ *			31.5uA, 1.5uA with 30uA boost are supported. This value
+ *			should be one of the QPNP_GPIO_PULL_*
+ * @vin_sel:		specifies the voltage level when the output is set to 1.
+ *			For an input gpio specifies the voltage level at which
+ *			the input is interpreted as a logical 1.
+ * @out_strength:	the amount of current supplied for an output gpio,
+ *			should be of the type QPNP_GPIO_STRENGTH_*
+ * @source_sel:		choose alternate function for the gpio. Certain gpios
+ *			can be paired (shorted) with each other. Some gpio pin
+ *			can act as alternate functions. This parameter should
+ *			be of type QPNP_GPIO_FUNC_*
+ * @inv_int_pol:	Invert polarity before feeding the line to the interrupt
+ *			module in pmic. This feature will almost be never used
+ *			since the pm8xxx interrupt block can detect both edges
+ *			and both levels.
+ * @master_en:		1 = Enable features within the GPIO block based on
+ *			configurations.
+ *			0 = Completely disable the GPIO block and let the pin
+ *			float with high impedance regardless of other settings.
+ */
+struct qpnp_gpio_cfg {
+	int		direction;
+	int		output_type;
+	int		output_value;
+	int		pull;
+	int		vin_sel;
+	int		out_strength;
+	int		src_select;
+	int		inv_int_pol;
+	int		master_en;
+};
+
+/**
+ * qpnp_gpio_config - Apply gpio configuration for Linux gpio
+ * @gpio: Linux gpio number to configure.
+ * @param: parameters to configure.
+ *
+ * This routine takes a Linux gpio number that corresponds with a
+ * PMIC gpio and applies the configuration specified in 'param'.
+ * This gpio number can be ascertained by of_get_gpio_flags() or
+ * the qpnp_gpio_map_gpio() API.
+ */
+int qpnp_gpio_config(int gpio, struct qpnp_gpio_cfg *param);
+
+/**
+ * qpnp_gpio_map_gpio - Obtain Linux GPIO number from device spec
+ * @slave_id: slave_id of the spmi_device for the gpio in question.
+ * @pmic_gpio: PMIC gpio number to lookup.
+ *
+ * This routine is used in legacy configurations that do not support
+ * Device Tree. If you are using Device Tree, you should not use this.
+ * For such cases, use of_get_gpio() instead.
+ */
+int qpnp_gpio_map_gpio(uint16_t slave_id, uint32_t pmic_gpio);