drivers/gpio: Altera soft IP GPIO driver
Adds a new driver for Altera soft GPIO IP. The driver is able to do read/write and allows GPIO to be a interrupt controller. Tested on Altera GHRD on interrupt handling and IO. v10: - Updated conflicting device tree parameters - Removed unused headers - Used macro instead of magic numbers for ngpio - Code readability cleanup using ?: and temporal variables - Removed leftover garbage and unnecessary function calls - Checked bgpio_init but unusable because Altera GPIO may not be a multiple of 8 bits v9: - Removed duplicated initialization on set_type using temporals to improve code readability in calling generic_handle_irq - Using ?: ternary to reduce code size v8: - Using for_each_set_bit - Added const for struct definition - Removed naggy pr_err - Sort alpha header - Remove unused macros - Use fixed width data types instead of unsigned long - Whitespace issue fixes - Removed _relaxed function for better compatibility across different CPU - Changed irq_create_mapping to platform_get_irq updated implementation to use gpiochip_irqchip_add - Reserve interrupt-cells number 2 in device tree binding for future use - Remove confusing sections on devicetree bindings - Added tristate Kconfig help text v7: - Used dev_warn instead of pr_warn - Clean up unnecesarry if else indentation v6: - Added irq_startup and irq_shutdown - Changed bitwise clamping style - Cleanup bitwise operation to improve readability change naming of mapped irqs from virq to mapped_irq v5: - Dispose irq_domain mapping correctly - Update optional binding description in binding docs v4: - Added vendor prefix to devicetree binding for IP specific properties using MMIO GPIO helper library instead of manually map PIO to memory - altera_gpio_chip inline struct documentation to kerneldoc - Using dev_ print to print a better failure message v2, v3: - Do not reference NO_IRQ - Updated irq_set_type to only allow the hardware configured irq type Signed-off-by: Tien Hock Loh <thloh@altera.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Tien Hock Loh
Linus Walleij
Родитель
d32efe3796
Коммит
c5abbba932
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@ -569,6 +569,12 @@ L: nios2-dev@lists.rocketboards.org (moderated for non-subscribers)
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S: Maintained
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F: drivers/mailbox/mailbox-altera.c
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ALTERA PIO DRIVER
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M: Tien Hock Loh <thloh@altera.com>
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L: linux-gpio@vger.kernel.org
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S: Maintained
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F: drivers/gpio/gpio-altera.c
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ALTERA TRIPLE SPEED ETHERNET DRIVER
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M: Vince Bridgers <vbridger@opensource.altera.com>
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L: netdev@vger.kernel.org
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@ -156,6 +156,16 @@ config GPIO_DWAPB
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Say Y or M here to build support for the Synopsys DesignWare APB
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GPIO block.
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config GPIO_ALTERA
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tristate "Altera GPIO"
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depends on OF_GPIO
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select GPIO_GENERIC
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select GPIOLIB_IRQCHIP
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help
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Say Y or M here to build support for the Altera PIO device.
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If driver is built as a module it will be called gpio-altera.
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config GPIO_IT8761E
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tristate "IT8761E GPIO support"
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depends on X86 # unconditional access to IO space.
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@ -17,6 +17,7 @@ obj-$(CONFIG_GPIO_74XX_MMIO) += gpio-74xx-mmio.o
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obj-$(CONFIG_GPIO_ADNP) += gpio-adnp.o
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obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o
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obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o
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obj-$(CONFIG_GPIO_ALTERA) += gpio-altera.o
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obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o
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obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizona.o
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obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o
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@ -0,0 +1,374 @@
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/*
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* Copyright (C) 2013 Altera Corporation
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* Based on gpio-mpc8xxx.c
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/io.h>
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#include <linux/of_gpio.h>
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#include <linux/platform_device.h>
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#define ALTERA_GPIO_MAX_NGPIO 32
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#define ALTERA_GPIO_DATA 0x0
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#define ALTERA_GPIO_DIR 0x4
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#define ALTERA_GPIO_IRQ_MASK 0x8
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#define ALTERA_GPIO_EDGE_CAP 0xc
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/**
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* struct altera_gpio_chip
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* @mmchip : memory mapped chip structure.
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* @gpio_lock : synchronization lock so that new irq/set/get requests
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will be blocked until the current one completes.
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* @interrupt_trigger : specifies the hardware configured IRQ trigger type
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(rising, falling, both, high)
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* @mapped_irq : kernel mapped irq number.
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*/
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struct altera_gpio_chip {
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struct of_mm_gpio_chip mmchip;
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spinlock_t gpio_lock;
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int interrupt_trigger;
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int mapped_irq;
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};
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static void altera_gpio_irq_unmask(struct irq_data *d)
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{
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struct altera_gpio_chip *altera_gc;
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struct of_mm_gpio_chip *mm_gc;
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unsigned long flags;
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u32 intmask;
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altera_gc = irq_data_get_irq_chip_data(d);
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mm_gc = &altera_gc->mmchip;
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spin_lock_irqsave(&altera_gc->gpio_lock, flags);
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intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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/* Set ALTERA_GPIO_IRQ_MASK bit to unmask */
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intmask |= BIT(irqd_to_hwirq(d));
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writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
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}
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static void altera_gpio_irq_mask(struct irq_data *d)
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{
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struct altera_gpio_chip *altera_gc;
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struct of_mm_gpio_chip *mm_gc;
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unsigned long flags;
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u32 intmask;
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altera_gc = irq_data_get_irq_chip_data(d);
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mm_gc = &altera_gc->mmchip;
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spin_lock_irqsave(&altera_gc->gpio_lock, flags);
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intmask = readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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/* Clear ALTERA_GPIO_IRQ_MASK bit to mask */
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intmask &= ~BIT(irqd_to_hwirq(d));
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writel(intmask, mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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spin_unlock_irqrestore(&altera_gc->gpio_lock, flags);
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}
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/**
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* This controller's IRQ type is synthesized in hardware, so this function
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* just checks if the requested set_type matches the synthesized IRQ type
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*/
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static int altera_gpio_irq_set_type(struct irq_data *d,
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unsigned int type)
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{
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struct altera_gpio_chip *altera_gc;
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altera_gc = irq_data_get_irq_chip_data(d);
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if (type == IRQ_TYPE_NONE)
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return 0;
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if (type == IRQ_TYPE_LEVEL_HIGH &&
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altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH)
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return 0;
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if (type == IRQ_TYPE_EDGE_RISING &&
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altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_RISING)
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return 0;
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if (type == IRQ_TYPE_EDGE_FALLING &&
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altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_FALLING)
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return 0;
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if (type == IRQ_TYPE_EDGE_BOTH &&
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altera_gc->interrupt_trigger == IRQ_TYPE_EDGE_BOTH)
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return 0;
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return -EINVAL;
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}
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static unsigned int altera_gpio_irq_startup(struct irq_data *d) {
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altera_gpio_irq_unmask(d);
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return 0;
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}
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static struct irq_chip altera_irq_chip = {
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.name = "altera-gpio",
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.irq_mask = altera_gpio_irq_mask,
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.irq_unmask = altera_gpio_irq_unmask,
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.irq_set_type = altera_gpio_irq_set_type,
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.irq_startup = altera_gpio_irq_startup,
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.irq_shutdown = altera_gpio_irq_mask,
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};
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static int altera_gpio_get(struct gpio_chip *gc, unsigned offset)
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{
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struct of_mm_gpio_chip *mm_gc;
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mm_gc = to_of_mm_gpio_chip(gc);
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return !!(readl(mm_gc->regs + ALTERA_GPIO_DATA) & BIT(offset));
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}
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static void altera_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
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{
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struct of_mm_gpio_chip *mm_gc;
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struct altera_gpio_chip *chip;
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unsigned long flags;
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unsigned int data_reg;
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mm_gc = to_of_mm_gpio_chip(gc);
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chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
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spin_lock_irqsave(&chip->gpio_lock, flags);
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data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
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if (value)
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data_reg |= BIT(offset);
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else
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data_reg &= ~BIT(offset);
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writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
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spin_unlock_irqrestore(&chip->gpio_lock, flags);
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}
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static int altera_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
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{
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struct of_mm_gpio_chip *mm_gc;
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struct altera_gpio_chip *chip;
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unsigned long flags;
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unsigned int gpio_ddr;
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mm_gc = to_of_mm_gpio_chip(gc);
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chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
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spin_lock_irqsave(&chip->gpio_lock, flags);
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/* Set pin as input, assumes software controlled IP */
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gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
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gpio_ddr &= ~BIT(offset);
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writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
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spin_unlock_irqrestore(&chip->gpio_lock, flags);
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return 0;
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}
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static int altera_gpio_direction_output(struct gpio_chip *gc,
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unsigned offset, int value)
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{
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struct of_mm_gpio_chip *mm_gc;
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struct altera_gpio_chip *chip;
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unsigned long flags;
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unsigned int data_reg, gpio_ddr;
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mm_gc = to_of_mm_gpio_chip(gc);
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chip = container_of(mm_gc, struct altera_gpio_chip, mmchip);
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spin_lock_irqsave(&chip->gpio_lock, flags);
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/* Sets the GPIO value */
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data_reg = readl(mm_gc->regs + ALTERA_GPIO_DATA);
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if (value)
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data_reg |= BIT(offset);
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else
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data_reg &= ~BIT(offset);
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writel(data_reg, mm_gc->regs + ALTERA_GPIO_DATA);
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/* Set pin as output, assumes software controlled IP */
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gpio_ddr = readl(mm_gc->regs + ALTERA_GPIO_DIR);
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gpio_ddr |= BIT(offset);
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writel(gpio_ddr, mm_gc->regs + ALTERA_GPIO_DIR);
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spin_unlock_irqrestore(&chip->gpio_lock, flags);
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return 0;
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}
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static void altera_gpio_irq_edge_handler(unsigned int irq,
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struct irq_desc *desc)
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{
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struct altera_gpio_chip *altera_gc;
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struct irq_chip *chip;
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struct of_mm_gpio_chip *mm_gc;
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struct irq_domain *irqdomain;
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unsigned long status;
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int i;
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altera_gc = irq_desc_get_handler_data(desc);
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chip = irq_desc_get_chip(desc);
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mm_gc = &altera_gc->mmchip;
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irqdomain = altera_gc->mmchip.gc.irqdomain;
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chained_irq_enter(chip, desc);
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while ((status =
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(readl(mm_gc->regs + ALTERA_GPIO_EDGE_CAP) &
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readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK)))) {
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writel(status, mm_gc->regs + ALTERA_GPIO_EDGE_CAP);
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for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
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generic_handle_irq(irq_find_mapping(irqdomain, i));
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}
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}
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chained_irq_exit(chip, desc);
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}
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static void altera_gpio_irq_leveL_high_handler(unsigned int irq,
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struct irq_desc *desc)
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{
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struct altera_gpio_chip *altera_gc;
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struct irq_chip *chip;
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struct of_mm_gpio_chip *mm_gc;
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struct irq_domain *irqdomain;
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unsigned long status;
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int i;
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altera_gc = irq_desc_get_handler_data(desc);
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chip = irq_desc_get_chip(desc);
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mm_gc = &altera_gc->mmchip;
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irqdomain = altera_gc->mmchip.gc.irqdomain;
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chained_irq_enter(chip, desc);
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status = readl(mm_gc->regs + ALTERA_GPIO_DATA);
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status &= readl(mm_gc->regs + ALTERA_GPIO_IRQ_MASK);
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for_each_set_bit(i, &status, mm_gc->gc.ngpio) {
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generic_handle_irq(irq_find_mapping(irqdomain, i));
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}
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chained_irq_exit(chip, desc);
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}
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int altera_gpio_probe(struct platform_device *pdev)
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{
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struct device_node *node = pdev->dev.of_node;
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int reg, ret;
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struct altera_gpio_chip *altera_gc;
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altera_gc = devm_kzalloc(&pdev->dev, sizeof(*altera_gc), GFP_KERNEL);
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if (!altera_gc)
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return -ENOMEM;
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spin_lock_init(&altera_gc->gpio_lock);
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if (of_property_read_u32(node, "altr,ngpio", ®))
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/* By default assume maximum ngpio */
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altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
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else
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altera_gc->mmchip.gc.ngpio = reg;
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if (altera_gc->mmchip.gc.ngpio > ALTERA_GPIO_MAX_NGPIO) {
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dev_warn(&pdev->dev,
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"ngpio is greater than %d, defaulting to %d\n",
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ALTERA_GPIO_MAX_NGPIO, ALTERA_GPIO_MAX_NGPIO);
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altera_gc->mmchip.gc.ngpio = ALTERA_GPIO_MAX_NGPIO;
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}
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altera_gc->mmchip.gc.direction_input = altera_gpio_direction_input;
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altera_gc->mmchip.gc.direction_output = altera_gpio_direction_output;
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altera_gc->mmchip.gc.get = altera_gpio_get;
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altera_gc->mmchip.gc.set = altera_gpio_set;
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altera_gc->mmchip.gc.owner = THIS_MODULE;
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altera_gc->mmchip.gc.dev = &pdev->dev;
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ret = of_mm_gpiochip_add(node, &altera_gc->mmchip);
|
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if (ret) {
|
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dev_err(&pdev->dev, "Failed adding memory mapped gpiochip\n");
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return ret;
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}
|
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platform_set_drvdata(pdev, altera_gc);
|
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altera_gc->mapped_irq = platform_get_irq(pdev, 0);
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if (altera_gc->mapped_irq < 0)
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goto skip_irq;
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if (of_property_read_u32(node, "altr,interrupt-type", ®)) {
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ret = -EINVAL;
|
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dev_err(&pdev->dev,
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"altr,interrupt-type value not set in device tree\n");
|
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goto teardown;
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}
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altera_gc->interrupt_trigger = reg;
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ret = gpiochip_irqchip_add(&altera_gc->mmchip.gc, &altera_irq_chip, 0,
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handle_simple_irq, IRQ_TYPE_NONE);
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|
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if (ret) {
|
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dev_info(&pdev->dev, "could not add irqchip\n");
|
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return ret;
|
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}
|
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|
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gpiochip_set_chained_irqchip(&altera_gc->mmchip.gc,
|
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&altera_irq_chip,
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altera_gc->mapped_irq,
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altera_gc->interrupt_trigger == IRQ_TYPE_LEVEL_HIGH ?
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altera_gpio_irq_leveL_high_handler :
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altera_gpio_irq_edge_handler);
|
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|
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skip_irq:
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return 0;
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teardown:
|
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pr_err("%s: registration failed with status %d\n",
|
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node->full_name, ret);
|
||||
|
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return ret;
|
||||
}
|
||||
|
||||
static int altera_gpio_remove(struct platform_device *pdev)
|
||||
{
|
||||
struct altera_gpio_chip *altera_gc = platform_get_drvdata(pdev);
|
||||
|
||||
gpiochip_remove(&altera_gc->mmchip.gc);
|
||||
|
||||
return -EIO;
|
||||
}
|
||||
|
||||
static const struct of_device_id altera_gpio_of_match[] = {
|
||||
{ .compatible = "altr,pio-1.0", },
|
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{},
|
||||
};
|
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MODULE_DEVICE_TABLE(of, altera_gpio_of_match);
|
||||
|
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static struct platform_driver altera_gpio_driver = {
|
||||
.driver = {
|
||||
.name = "altera_gpio",
|
||||
.of_match_table = of_match_ptr(altera_gpio_of_match),
|
||||
},
|
||||
.probe = altera_gpio_probe,
|
||||
.remove = altera_gpio_remove,
|
||||
};
|
||||
|
||||
static int __init altera_gpio_init(void)
|
||||
{
|
||||
return platform_driver_register(&altera_gpio_driver);
|
||||
}
|
||||
subsys_initcall(altera_gpio_init);
|
||||
|
||||
static void __exit altera_gpio_exit(void)
|
||||
{
|
||||
platform_driver_unregister(&altera_gpio_driver);
|
||||
}
|
||||
module_exit(altera_gpio_exit);
|
||||
|
||||
MODULE_AUTHOR("Tien Hock Loh <thloh@altera.com>");
|
||||
MODULE_DESCRIPTION("Altera GPIO driver");
|
||||
MODULE_LICENSE("GPL");
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||||
Загрузка…
Ссылка в новой задаче