diff options
Diffstat (limited to 'arch/arm/plat-mxc/gpio.c')
| -rw-r--r-- | arch/arm/plat-mxc/gpio.c | 253 |
1 files changed, 253 insertions, 0 deletions
diff --git a/arch/arm/plat-mxc/gpio.c b/arch/arm/plat-mxc/gpio.c new file mode 100644 index 00000000000..4a7736717d8 --- /dev/null +++ b/arch/arm/plat-mxc/gpio.c @@ -0,0 +1,253 @@ +/* + * MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de> + * Copyright 2008 Juergen Beisert, kernel@pengutronix.de + * + * Based on code from Freescale, + * Copyright 2004-2006 Freescale Semiconductor, Inc. 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 + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * 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. + * + * 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 Street, Fifth Floor, Boston, MA 02110-1301, USA. + */ + +#include <linux/init.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/gpio.h> +#include <asm/hardware.h> +#include <asm-generic/bug.h> + +static struct mxc_gpio_port *mxc_gpio_ports; +static int gpio_table_size; + +/* Note: This driver assumes 32 GPIOs are handled in one register */ + +static void _clear_gpio_irqstatus(struct mxc_gpio_port *port, u32 index) +{ + __raw_writel(1 << index, port->base + GPIO_ISR); +} + +static void _set_gpio_irqenable(struct mxc_gpio_port *port, u32 index, + int enable) +{ + u32 l; + + l = __raw_readl(port->base + GPIO_IMR); + l = (l & (~(1 << index))) | (!!enable << index); + __raw_writel(l, port->base + GPIO_IMR); +} + +static void gpio_ack_irq(u32 irq) +{ + u32 gpio = irq_to_gpio(irq); + _clear_gpio_irqstatus(&mxc_gpio_ports[gpio / 32], gpio & 0x1f); +} + +static void gpio_mask_irq(u32 irq) +{ + u32 gpio = irq_to_gpio(irq); + _set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 0); +} + +static void gpio_unmask_irq(u32 irq) +{ + u32 gpio = irq_to_gpio(irq); + _set_gpio_irqenable(&mxc_gpio_ports[gpio / 32], gpio & 0x1f, 1); +} + +static int gpio_set_irq_type(u32 irq, u32 type) +{ + u32 gpio = irq_to_gpio(irq); + struct mxc_gpio_port *port = &mxc_gpio_ports[gpio / 32]; + u32 bit, val; + int edge; + void __iomem *reg = port->base; + + switch (type) { + case IRQT_RISING: + edge = GPIO_INT_RISE_EDGE; + break; + case IRQT_FALLING: + edge = GPIO_INT_FALL_EDGE; + break; + case IRQT_LOW: + edge = GPIO_INT_LOW_LEV; + break; + case IRQT_HIGH: + edge = GPIO_INT_HIGH_LEV; + break; + default: /* this includes IRQT_BOTHEDGE */ + return -EINVAL; + } + + reg += GPIO_ICR1 + ((gpio & 0x10) >> 2); /* lower or upper register */ + bit = gpio & 0xf; + val = __raw_readl(reg) & ~(0x3 << (bit << 1)); + __raw_writel(val | (edge << (bit << 1)), reg); + _clear_gpio_irqstatus(port, gpio & 0x1f); + + return 0; +} + +/* handle n interrupts in one status register */ +static void mxc_gpio_irq_handler(struct mxc_gpio_port *port, u32 irq_stat) +{ + u32 gpio_irq_no; + + gpio_irq_no = port->virtual_irq_start; + for (; irq_stat != 0; irq_stat >>= 1, gpio_irq_no++) { + + if ((irq_stat & 1) == 0) + continue; + + BUG_ON(!(irq_desc[gpio_irq_no].handle_irq)); + irq_desc[gpio_irq_no].handle_irq(gpio_irq_no, + &irq_desc[gpio_irq_no]); + } +} + +#ifdef CONFIG_ARCH_MX3 +/* MX3 has one interrupt *per* gpio port */ +static void mx3_gpio_irq_handler(u32 irq, struct irq_desc *desc) +{ + u32 irq_stat; + struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq); + + irq_stat = __raw_readl(port->base + GPIO_ISR) & + __raw_readl(port->base + GPIO_IMR); + BUG_ON(!irq_stat); + mxc_gpio_irq_handler(port, irq_stat); +} +#endif + +#ifdef CONFIG_ARCH_MX2 +/* MX2 has one interrupt *for all* gpio ports */ +static void mx2_gpio_irq_handler(u32 irq, struct irq_desc *desc) +{ + int i; + u32 irq_msk, irq_stat; + struct mxc_gpio_port *port = (struct mxc_gpio_port *)get_irq_data(irq); + + /* walk through all interrupt status registers */ + for (i = 0; i < gpio_table_size; i++) { + irq_msk = __raw_readl(port[i].base + GPIO_IMR); + if (!irq_msk) + continue; + + irq_stat = __raw_readl(port[i].base + GPIO_ISR) & irq_msk; + if (irq_stat) + mxc_gpio_irq_handler(&port[i], irq_stat); + } +} +#endif + +static struct irq_chip gpio_irq_chip = { + .ack = gpio_ack_irq, + .mask = gpio_mask_irq, + .unmask = gpio_unmask_irq, + .set_type = gpio_set_irq_type, +}; + +static void _set_gpio_direction(struct gpio_chip *chip, unsigned offset, + int dir) +{ + struct mxc_gpio_port *port = + container_of(chip, struct mxc_gpio_port, chip); + u32 l; + + l = __raw_readl(port->base + GPIO_GDIR); + if (dir) + l |= 1 << offset; + else + l &= ~(1 << offset); + __raw_writel(l, port->base + GPIO_GDIR); +} + +static void mxc_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct mxc_gpio_port *port = + container_of(chip, struct mxc_gpio_port, chip); + void __iomem *reg = port->base + GPIO_DR; + u32 l; + + l = (__raw_readl(reg) & (~(1 << offset))) | (value << offset); + __raw_writel(l, reg); +} + +static int mxc_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct mxc_gpio_port *port = + container_of(chip, struct mxc_gpio_port, chip); + + return (__raw_readl(port->base + GPIO_DR) >> offset) & 1; +} + +static int mxc_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + _set_gpio_direction(chip, offset, 0); + return 0; +} + +static int mxc_gpio_direction_output(struct gpio_chip *chip, + unsigned offset, int value) +{ + _set_gpio_direction(chip, offset, 1); + mxc_gpio_set(chip, offset, value); + return 0; +} + +int __init mxc_gpio_init(struct mxc_gpio_port *port, int cnt) +{ + int i, j; + + /* save for local usage */ + mxc_gpio_ports = port; + gpio_table_size = cnt; + + printk(KERN_INFO "MXC GPIO hardware\n"); + + for (i = 0; i < cnt; i++) { + /* disable the interrupt and clear the status */ + __raw_writel(0, port[i].base + GPIO_IMR); + __raw_writel(~0, port[i].base + GPIO_ISR); + for (j = port[i].virtual_irq_start; + j < port[i].virtual_irq_start + 32; j++) { + set_irq_chip(j, &gpio_irq_chip); + set_irq_handler(j, handle_edge_irq); + set_irq_flags(j, IRQF_VALID); + } + + /* register gpio chip */ + port[i].chip.direction_input = mxc_gpio_direction_input; + port[i].chip.direction_output = mxc_gpio_direction_output; + port[i].chip.get = mxc_gpio_get; + port[i].chip.set = mxc_gpio_set; + port[i].chip.base = i * 32; + port[i].chip.ngpio = 32; + + /* its a serious configuration bug when it fails */ + BUG_ON( gpiochip_add(&port[i].chip) < 0 ); + +#ifdef CONFIG_ARCH_MX3 + /* setup one handler for each entry */ + set_irq_chained_handler(port[i].irq, mx3_gpio_irq_handler); + set_irq_data(port[i].irq, &port[i]); +#endif + } + +#ifdef CONFIG_ARCH_MX2 + /* setup one handler for all GPIO interrupts */ + set_irq_chained_handler(port[0].irq, mx2_gpio_irq_handler); + set_irq_data(port[0].irq, port); +#endif + return 0; +} |