Commit 25cf2507 authored by Mathias Nyman's avatar Mathias Nyman Committed by Grant Likely

gpio: add MSIC gpio driver

Add gpio support for Intel MSIC chips found in Intel Medfield platforms.
MSIC supports totally 24 GPIOs with 16 low voltage and 8 high voltage pins.
Driver uses MSIC mfd interface for MSIC access.

(Updated comment to indicate why locking is actually safe)
Signed-off-by: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGrant Likely <grant.likely@secretlab.ca>
parent fd454997
......@@ -520,4 +520,12 @@ config GPIO_TPS65910
help
Select this option to enable GPIO driver for the TPS65910
chip family.
config GPIO_MSIC
bool "Intel MSIC mixed signal gpio support"
depends on MFD_INTEL_MSIC
help
Enable support for GPIO on intel MSIC controllers found in
intel MID devices
endif
......@@ -33,6 +33,7 @@ obj-$(CONFIG_GPIO_MCP23S08) += gpio-mcp23s08.o
obj-$(CONFIG_GPIO_ML_IOH) += gpio-ml-ioh.o
obj-$(CONFIG_GPIO_MPC5200) += gpio-mpc5200.o
obj-$(CONFIG_GPIO_MPC8XXX) += gpio-mpc8xxx.o
obj-$(CONFIG_GPIO_MSIC) += gpio-msic.o
obj-$(CONFIG_GPIO_MSM_V1) += gpio-msm-v1.o
obj-$(CONFIG_GPIO_MSM_V2) += gpio-msm-v2.o
obj-$(CONFIG_GPIO_MXC) += gpio-mxc.o
......
/*
* Intel Medfield MSIC GPIO driver>
* Copyright (c) 2011, Intel Corporation.
*
* Author: Mathias Nyman <mathias.nyman@linux.intel.com>
* Based on intel_pmic_gpio.c
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/mfd/intel_msic.h>
/* the offset for the mapping of global gpio pin to irq */
#define MSIC_GPIO_IRQ_OFFSET 0x100
#define MSIC_GPIO_DIR_IN 0
#define MSIC_GPIO_DIR_OUT BIT(5)
#define MSIC_GPIO_TRIG_FALL BIT(1)
#define MSIC_GPIO_TRIG_RISE BIT(2)
/* masks for msic gpio output GPIOxxxxCTLO registers */
#define MSIC_GPIO_DIR_MASK BIT(5)
#define MSIC_GPIO_DRV_MASK BIT(4)
#define MSIC_GPIO_REN_MASK BIT(3)
#define MSIC_GPIO_RVAL_MASK (BIT(2) | BIT(1))
#define MSIC_GPIO_DOUT_MASK BIT(0)
/* masks for msic gpio input GPIOxxxxCTLI registers */
#define MSIC_GPIO_GLBYP_MASK BIT(5)
#define MSIC_GPIO_DBNC_MASK (BIT(4) | BIT(3))
#define MSIC_GPIO_INTCNT_MASK (BIT(2) | BIT(1))
#define MSIC_GPIO_DIN_MASK BIT(0)
#define MSIC_NUM_GPIO 24
struct msic_gpio {
struct platform_device *pdev;
struct mutex buslock;
struct gpio_chip chip;
int irq;
unsigned irq_base;
unsigned long trig_change_mask;
unsigned trig_type;
};
/*
* MSIC has 24 gpios, 16 low voltage (1.2-1.8v) and 8 high voltage (3v).
* Both the high and low voltage gpios are divided in two banks.
* GPIOs are numbered with GPIO0LV0 as gpio_base in the following order:
* GPIO0LV0..GPIO0LV7: low voltage, bank 0, gpio_base
* GPIO1LV0..GPIO1LV7: low voltage, bank 1, gpio_base + 8
* GPIO0HV0..GPIO0HV3: high voltage, bank 0, gpio_base + 16
* GPIO1HV0..GPIO1HV3: high voltage, bank 1, gpio_base + 20
*/
static int msic_gpio_to_ireg(unsigned offset)
{
if (offset >= MSIC_NUM_GPIO)
return -EINVAL;
if (offset < 8)
return INTEL_MSIC_GPIO0LV0CTLI - offset;
if (offset < 16)
return INTEL_MSIC_GPIO1LV0CTLI - offset + 8;
if (offset < 20)
return INTEL_MSIC_GPIO0HV0CTLI - offset + 16;
return INTEL_MSIC_GPIO1HV0CTLI - offset + 20;
}
static int msic_gpio_to_oreg(unsigned offset)
{
if (offset >= MSIC_NUM_GPIO)
return -EINVAL;
if (offset < 8)
return INTEL_MSIC_GPIO0LV0CTLO - offset;
if (offset < 16)
return INTEL_MSIC_GPIO1LV0CTLO - offset + 8;
if (offset < 20)
return INTEL_MSIC_GPIO0HV0CTLO - offset + 16;
return INTEL_MSIC_GPIO1HV0CTLO + offset + 20;
}
static int msic_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
int reg;
reg = msic_gpio_to_oreg(offset);
if (reg < 0)
return reg;
return intel_msic_reg_update(reg, MSIC_GPIO_DIR_IN, MSIC_GPIO_DIR_MASK);
}
static int msic_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
int reg;
unsigned mask;
value = (!!value) | MSIC_GPIO_DIR_OUT;
mask = MSIC_GPIO_DIR_MASK | MSIC_GPIO_DOUT_MASK;
reg = msic_gpio_to_oreg(offset);
if (reg < 0)
return reg;
return intel_msic_reg_update(reg, value, mask);
}
static int msic_gpio_get(struct gpio_chip *chip, unsigned offset)
{
u8 r;
int ret;
int reg;
reg = msic_gpio_to_ireg(offset);
if (reg < 0)
return reg;
ret = intel_msic_reg_read(reg, &r);
if (ret < 0)
return ret;
return r & MSIC_GPIO_DIN_MASK;
}
static void msic_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
int reg;
reg = msic_gpio_to_oreg(offset);
if (reg < 0)
return;
intel_msic_reg_update(reg, !!value , MSIC_GPIO_DOUT_MASK);
}
/*
* This is called from genirq with mg->buslock locked and
* irq_desc->lock held. We can not access the scu bus here, so we
* store the change and update in the bus_sync_unlock() function below
*/
static int msic_irq_type(struct irq_data *data, unsigned type)
{
struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
u32 gpio = data->irq - mg->irq_base;
if (gpio >= mg->chip.ngpio)
return -EINVAL;
/* mark for which gpio the trigger changed, protected by buslock */
mg->trig_change_mask |= (1 << gpio);
mg->trig_type = type;
return 0;
}
static int msic_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct msic_gpio *mg = container_of(chip, struct msic_gpio, chip);
return mg->irq_base + offset;
}
static void msic_bus_lock(struct irq_data *data)
{
struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
mutex_lock(&mg->buslock);
}
static void msic_bus_sync_unlock(struct irq_data *data)
{
struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
int offset;
int reg;
u8 trig = 0;
/* We can only get one change at a time as the buslock covers the
entire transaction. The irq_desc->lock is dropped before we are
called but that is fine */
if (mg->trig_change_mask) {
offset = __ffs(mg->trig_change_mask);
reg = msic_gpio_to_ireg(offset);
if (reg < 0)
goto out;
if (mg->trig_type & IRQ_TYPE_EDGE_RISING)
trig |= MSIC_GPIO_TRIG_RISE;
if (mg->trig_type & IRQ_TYPE_EDGE_FALLING)
trig |= MSIC_GPIO_TRIG_FALL;
intel_msic_reg_update(reg, trig, MSIC_GPIO_INTCNT_MASK);
mg->trig_change_mask = 0;
}
out:
mutex_unlock(&mg->buslock);
}
/* Firmware does all the masking and unmasking for us, no masking here. */
static void msic_irq_unmask(struct irq_data *data) { }
static void msic_irq_mask(struct irq_data *data) { }
static struct irq_chip msic_irqchip = {
.name = "MSIC-GPIO",
.irq_mask = msic_irq_mask,
.irq_unmask = msic_irq_unmask,
.irq_set_type = msic_irq_type,
.irq_bus_lock = msic_bus_lock,
.irq_bus_sync_unlock = msic_bus_sync_unlock,
};
static void msic_gpio_irq_handler(unsigned irq, struct irq_desc *desc)
{
struct irq_data *data = irq_desc_get_irq_data(desc);
struct msic_gpio *mg = irq_data_get_irq_handler_data(data);
struct irq_chip *chip = irq_data_get_irq_chip(data);
struct intel_msic *msic = pdev_to_intel_msic(mg->pdev);
int i;
int bitnr;
u8 pin;
unsigned long pending = 0;
for (i = 0; i < (mg->chip.ngpio / BITS_PER_BYTE); i++) {
intel_msic_irq_read(msic, INTEL_MSIC_GPIO0LVIRQ + i, &pin);
pending = pin;
if (pending) {
for_each_set_bit(bitnr, &pending, BITS_PER_BYTE)
generic_handle_irq(mg->irq_base +
(i * BITS_PER_BYTE) + bitnr);
}
}
chip->irq_eoi(data);
}
static int __devinit platform_msic_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct intel_msic_gpio_pdata *pdata = dev->platform_data;
struct msic_gpio *mg;
int irq = platform_get_irq(pdev, 0);
int retval;
int i;
if (irq < 0) {
dev_err(dev, "no IRQ line\n");
return -EINVAL;
}
if (!pdata || !pdata->gpio_base) {
dev_err(dev, "incorrect or missing platform data\n");
return -EINVAL;
}
mg = kzalloc(sizeof(*mg), GFP_KERNEL);
if (!mg)
return -ENOMEM;
dev_set_drvdata(dev, mg);
mg->pdev = pdev;
mg->irq = irq;
mg->irq_base = pdata->gpio_base + MSIC_GPIO_IRQ_OFFSET;
mg->chip.label = "msic_gpio";
mg->chip.direction_input = msic_gpio_direction_input;
mg->chip.direction_output = msic_gpio_direction_output;
mg->chip.get = msic_gpio_get;
mg->chip.set = msic_gpio_set;
mg->chip.to_irq = msic_gpio_to_irq;
mg->chip.base = pdata->gpio_base;
mg->chip.ngpio = MSIC_NUM_GPIO;
mg->chip.can_sleep = 1;
mg->chip.dev = dev;
mutex_init(&mg->buslock);
retval = gpiochip_add(&mg->chip);
if (retval) {
dev_err(dev, "Adding MSIC gpio chip failed\n");
goto err;
}
for (i = 0; i < mg->chip.ngpio; i++) {
irq_set_chip_data(i + mg->irq_base, mg);
irq_set_chip_and_handler_name(i + mg->irq_base,
&msic_irqchip,
handle_simple_irq,
"demux");
}
irq_set_chained_handler(mg->irq, msic_gpio_irq_handler);
irq_set_handler_data(mg->irq, mg);
return 0;
err:
kfree(mg);
return retval;
}
static struct platform_driver platform_msic_gpio_driver = {
.driver = {
.name = "msic_gpio",
.owner = THIS_MODULE,
},
.probe = platform_msic_gpio_probe,
};
static int __init platform_msic_gpio_init(void)
{
return platform_driver_register(&platform_msic_gpio_driver);
}
subsys_initcall(platform_msic_gpio_init);
MODULE_AUTHOR("Mathias Nyman <mathias.nyman@linux.intel.com>");
MODULE_DESCRIPTION("Intel Medfield MSIC GPIO driver");
MODULE_LICENSE("GPL v2");
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