![Linus Walleij](/assets/img/avatar_default.png)
This is a driver so only include <linux/gpio/driver.h>. Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
331 lines
8.3 KiB
C
331 lines
8.3 KiB
C
/*
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* Intel Medfield MSIC GPIO driver>
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* Copyright (c) 2011, Intel Corporation.
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*
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* Author: Mathias Nyman <mathias.nyman@linux.intel.com>
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* Based on intel_pmic_gpio.c
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <linux/gpio/driver.h>
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#include <linux/platform_device.h>
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#include <linux/mfd/intel_msic.h>
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/* the offset for the mapping of global gpio pin to irq */
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#define MSIC_GPIO_IRQ_OFFSET 0x100
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#define MSIC_GPIO_DIR_IN 0
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#define MSIC_GPIO_DIR_OUT BIT(5)
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#define MSIC_GPIO_TRIG_FALL BIT(1)
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#define MSIC_GPIO_TRIG_RISE BIT(2)
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/* masks for msic gpio output GPIOxxxxCTLO registers */
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#define MSIC_GPIO_DIR_MASK BIT(5)
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#define MSIC_GPIO_DRV_MASK BIT(4)
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#define MSIC_GPIO_REN_MASK BIT(3)
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#define MSIC_GPIO_RVAL_MASK (BIT(2) | BIT(1))
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#define MSIC_GPIO_DOUT_MASK BIT(0)
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/* masks for msic gpio input GPIOxxxxCTLI registers */
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#define MSIC_GPIO_GLBYP_MASK BIT(5)
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#define MSIC_GPIO_DBNC_MASK (BIT(4) | BIT(3))
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#define MSIC_GPIO_INTCNT_MASK (BIT(2) | BIT(1))
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#define MSIC_GPIO_DIN_MASK BIT(0)
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#define MSIC_NUM_GPIO 24
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struct msic_gpio {
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struct platform_device *pdev;
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struct mutex buslock;
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struct gpio_chip chip;
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int irq;
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unsigned irq_base;
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unsigned long trig_change_mask;
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unsigned trig_type;
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};
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/*
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* MSIC has 24 gpios, 16 low voltage (1.2-1.8v) and 8 high voltage (3v).
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* Both the high and low voltage gpios are divided in two banks.
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* GPIOs are numbered with GPIO0LV0 as gpio_base in the following order:
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* GPIO0LV0..GPIO0LV7: low voltage, bank 0, gpio_base
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* GPIO1LV0..GPIO1LV7: low voltage, bank 1, gpio_base + 8
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* GPIO0HV0..GPIO0HV3: high voltage, bank 0, gpio_base + 16
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* GPIO1HV0..GPIO1HV3: high voltage, bank 1, gpio_base + 20
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*/
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static int msic_gpio_to_ireg(unsigned offset)
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{
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if (offset >= MSIC_NUM_GPIO)
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return -EINVAL;
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if (offset < 8)
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return INTEL_MSIC_GPIO0LV0CTLI - offset;
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if (offset < 16)
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return INTEL_MSIC_GPIO1LV0CTLI - offset + 8;
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if (offset < 20)
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return INTEL_MSIC_GPIO0HV0CTLI - offset + 16;
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return INTEL_MSIC_GPIO1HV0CTLI - offset + 20;
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}
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static int msic_gpio_to_oreg(unsigned offset)
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{
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if (offset >= MSIC_NUM_GPIO)
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return -EINVAL;
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if (offset < 8)
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return INTEL_MSIC_GPIO0LV0CTLO - offset;
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if (offset < 16)
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return INTEL_MSIC_GPIO1LV0CTLO - offset + 8;
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if (offset < 20)
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return INTEL_MSIC_GPIO0HV0CTLO - offset + 16;
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return INTEL_MSIC_GPIO1HV0CTLO - offset + 20;
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}
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static int msic_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
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{
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int reg;
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reg = msic_gpio_to_oreg(offset);
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if (reg < 0)
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return reg;
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return intel_msic_reg_update(reg, MSIC_GPIO_DIR_IN, MSIC_GPIO_DIR_MASK);
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}
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static int msic_gpio_direction_output(struct gpio_chip *chip,
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unsigned offset, int value)
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{
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int reg;
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unsigned mask;
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value = (!!value) | MSIC_GPIO_DIR_OUT;
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mask = MSIC_GPIO_DIR_MASK | MSIC_GPIO_DOUT_MASK;
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reg = msic_gpio_to_oreg(offset);
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if (reg < 0)
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return reg;
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return intel_msic_reg_update(reg, value, mask);
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}
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static int msic_gpio_get(struct gpio_chip *chip, unsigned offset)
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{
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u8 r;
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int ret;
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int reg;
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reg = msic_gpio_to_ireg(offset);
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if (reg < 0)
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return reg;
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ret = intel_msic_reg_read(reg, &r);
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if (ret < 0)
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return ret;
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return !!(r & MSIC_GPIO_DIN_MASK);
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}
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static void msic_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
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{
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int reg;
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reg = msic_gpio_to_oreg(offset);
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if (reg < 0)
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return;
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intel_msic_reg_update(reg, !!value , MSIC_GPIO_DOUT_MASK);
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}
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/*
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* This is called from genirq with mg->buslock locked and
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* irq_desc->lock held. We can not access the scu bus here, so we
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* store the change and update in the bus_sync_unlock() function below
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*/
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static int msic_irq_type(struct irq_data *data, unsigned type)
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{
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struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
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u32 gpio = data->irq - mg->irq_base;
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if (gpio >= mg->chip.ngpio)
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return -EINVAL;
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/* mark for which gpio the trigger changed, protected by buslock */
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mg->trig_change_mask |= (1 << gpio);
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mg->trig_type = type;
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return 0;
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}
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static int msic_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
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{
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struct msic_gpio *mg = gpiochip_get_data(chip);
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return mg->irq_base + offset;
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}
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static void msic_bus_lock(struct irq_data *data)
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{
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struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
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mutex_lock(&mg->buslock);
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}
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static void msic_bus_sync_unlock(struct irq_data *data)
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{
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struct msic_gpio *mg = irq_data_get_irq_chip_data(data);
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int offset;
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int reg;
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u8 trig = 0;
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/* We can only get one change at a time as the buslock covers the
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entire transaction. The irq_desc->lock is dropped before we are
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called but that is fine */
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if (mg->trig_change_mask) {
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offset = __ffs(mg->trig_change_mask);
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reg = msic_gpio_to_ireg(offset);
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if (reg < 0)
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goto out;
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if (mg->trig_type & IRQ_TYPE_EDGE_RISING)
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trig |= MSIC_GPIO_TRIG_RISE;
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if (mg->trig_type & IRQ_TYPE_EDGE_FALLING)
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trig |= MSIC_GPIO_TRIG_FALL;
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intel_msic_reg_update(reg, trig, MSIC_GPIO_INTCNT_MASK);
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mg->trig_change_mask = 0;
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}
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out:
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mutex_unlock(&mg->buslock);
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}
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/* Firmware does all the masking and unmasking for us, no masking here. */
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static void msic_irq_unmask(struct irq_data *data) { }
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static void msic_irq_mask(struct irq_data *data) { }
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static struct irq_chip msic_irqchip = {
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.name = "MSIC-GPIO",
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.irq_mask = msic_irq_mask,
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.irq_unmask = msic_irq_unmask,
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.irq_set_type = msic_irq_type,
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.irq_bus_lock = msic_bus_lock,
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.irq_bus_sync_unlock = msic_bus_sync_unlock,
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};
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static void msic_gpio_irq_handler(struct irq_desc *desc)
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{
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struct irq_data *data = irq_desc_get_irq_data(desc);
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struct msic_gpio *mg = irq_data_get_irq_handler_data(data);
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struct irq_chip *chip = irq_data_get_irq_chip(data);
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struct intel_msic *msic = pdev_to_intel_msic(mg->pdev);
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int i;
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int bitnr;
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u8 pin;
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unsigned long pending = 0;
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for (i = 0; i < (mg->chip.ngpio / BITS_PER_BYTE); i++) {
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intel_msic_irq_read(msic, INTEL_MSIC_GPIO0LVIRQ + i, &pin);
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pending = pin;
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if (pending) {
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for_each_set_bit(bitnr, &pending, BITS_PER_BYTE)
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generic_handle_irq(mg->irq_base +
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(i * BITS_PER_BYTE) + bitnr);
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}
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}
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chip->irq_eoi(data);
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}
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static int platform_msic_gpio_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct intel_msic_gpio_pdata *pdata = dev_get_platdata(dev);
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struct msic_gpio *mg;
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int irq = platform_get_irq(pdev, 0);
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int retval;
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int i;
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if (irq < 0) {
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dev_err(dev, "no IRQ line: %d\n", irq);
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return irq;
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}
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if (!pdata || !pdata->gpio_base) {
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dev_err(dev, "incorrect or missing platform data\n");
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return -EINVAL;
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}
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mg = kzalloc(sizeof(*mg), GFP_KERNEL);
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if (!mg)
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return -ENOMEM;
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dev_set_drvdata(dev, mg);
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mg->pdev = pdev;
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mg->irq = irq;
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mg->irq_base = pdata->gpio_base + MSIC_GPIO_IRQ_OFFSET;
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mg->chip.label = "msic_gpio";
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mg->chip.direction_input = msic_gpio_direction_input;
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mg->chip.direction_output = msic_gpio_direction_output;
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mg->chip.get = msic_gpio_get;
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mg->chip.set = msic_gpio_set;
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mg->chip.to_irq = msic_gpio_to_irq;
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mg->chip.base = pdata->gpio_base;
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mg->chip.ngpio = MSIC_NUM_GPIO;
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mg->chip.can_sleep = true;
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mg->chip.parent = dev;
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mutex_init(&mg->buslock);
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retval = gpiochip_add_data(&mg->chip, mg);
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if (retval) {
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dev_err(dev, "Adding MSIC gpio chip failed\n");
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goto err;
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}
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for (i = 0; i < mg->chip.ngpio; i++) {
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irq_set_chip_data(i + mg->irq_base, mg);
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irq_set_chip_and_handler(i + mg->irq_base,
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&msic_irqchip,
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handle_simple_irq);
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}
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irq_set_chained_handler_and_data(mg->irq, msic_gpio_irq_handler, mg);
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return 0;
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err:
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kfree(mg);
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return retval;
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}
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static struct platform_driver platform_msic_gpio_driver = {
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.driver = {
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.name = "msic_gpio",
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},
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.probe = platform_msic_gpio_probe,
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};
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static int __init platform_msic_gpio_init(void)
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{
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return platform_driver_register(&platform_msic_gpio_driver);
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}
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subsys_initcall(platform_msic_gpio_init);
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