diff options
Diffstat (limited to 'kernel/arch/powerpc/sysdev/qe_lib/gpio.c')
| -rw-r--r-- | kernel/arch/powerpc/sysdev/qe_lib/gpio.c | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/kernel/arch/powerpc/sysdev/qe_lib/gpio.c b/kernel/arch/powerpc/sysdev/qe_lib/gpio.c new file mode 100644 index 000000000..521e67a49 --- /dev/null +++ b/kernel/arch/powerpc/sysdev/qe_lib/gpio.c @@ -0,0 +1,317 @@ +/* + * QUICC Engine GPIOs + * + * Copyright (c) MontaVista Software, Inc. 2008. + * + * Author: Anton Vorontsov <avorontsov@ru.mvista.com> + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/spinlock.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_gpio.h> +#include <linux/gpio.h> +#include <linux/slab.h> +#include <linux/export.h> +#include <asm/qe.h> + +struct qe_gpio_chip { + struct of_mm_gpio_chip mm_gc; + spinlock_t lock; + + unsigned long pin_flags[QE_PIO_PINS]; +#define QE_PIN_REQUESTED 0 + + /* shadowed data register to clear/set bits safely */ + u32 cpdata; + + /* saved_regs used to restore dedicated functions */ + struct qe_pio_regs saved_regs; +}; + +static inline struct qe_gpio_chip * +to_qe_gpio_chip(struct of_mm_gpio_chip *mm_gc) +{ + return container_of(mm_gc, struct qe_gpio_chip, mm_gc); +} + +static void qe_gpio_save_regs(struct of_mm_gpio_chip *mm_gc) +{ + struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc); + struct qe_pio_regs __iomem *regs = mm_gc->regs; + + qe_gc->cpdata = in_be32(®s->cpdata); + qe_gc->saved_regs.cpdata = qe_gc->cpdata; + qe_gc->saved_regs.cpdir1 = in_be32(®s->cpdir1); + qe_gc->saved_regs.cpdir2 = in_be32(®s->cpdir2); + qe_gc->saved_regs.cppar1 = in_be32(®s->cppar1); + qe_gc->saved_regs.cppar2 = in_be32(®s->cppar2); + qe_gc->saved_regs.cpodr = in_be32(®s->cpodr); +} + +static int qe_gpio_get(struct gpio_chip *gc, unsigned int gpio) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct qe_pio_regs __iomem *regs = mm_gc->regs; + u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio); + + return in_be32(®s->cpdata) & pin_mask; +} + +static void qe_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc); + struct qe_pio_regs __iomem *regs = mm_gc->regs; + unsigned long flags; + u32 pin_mask = 1 << (QE_PIO_PINS - 1 - gpio); + + spin_lock_irqsave(&qe_gc->lock, flags); + + if (val) + qe_gc->cpdata |= pin_mask; + else + qe_gc->cpdata &= ~pin_mask; + + out_be32(®s->cpdata, qe_gc->cpdata); + + spin_unlock_irqrestore(&qe_gc->lock, flags); +} + +static int qe_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc); + unsigned long flags; + + spin_lock_irqsave(&qe_gc->lock, flags); + + __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_IN, 0, 0, 0); + + spin_unlock_irqrestore(&qe_gc->lock, flags); + + return 0; +} + +static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) +{ + struct of_mm_gpio_chip *mm_gc = to_of_mm_gpio_chip(gc); + struct qe_gpio_chip *qe_gc = to_qe_gpio_chip(mm_gc); + unsigned long flags; + + qe_gpio_set(gc, gpio, val); + + spin_lock_irqsave(&qe_gc->lock, flags); + + __par_io_config_pin(mm_gc->regs, gpio, QE_PIO_DIR_OUT, 0, 0, 0); + + spin_unlock_irqrestore(&qe_gc->lock, flags); + + return 0; +} + +struct qe_pin { + /* + * The qe_gpio_chip name is unfortunate, we should change that to + * something like qe_pio_controller. Someday. + */ + struct qe_gpio_chip *controller; + int num; +}; + +/** + * qe_pin_request - Request a QE pin + * @np: device node to get a pin from + * @index: index of a pin in the device tree + * Context: non-atomic + * + * This function return qe_pin so that you could use it with the rest of + * the QE Pin Multiplexing API. + */ +struct qe_pin *qe_pin_request(struct device_node *np, int index) +{ + struct qe_pin *qe_pin; + struct gpio_chip *gc; + struct of_mm_gpio_chip *mm_gc; + struct qe_gpio_chip *qe_gc; + int err; + unsigned long flags; + + qe_pin = kzalloc(sizeof(*qe_pin), GFP_KERNEL); + if (!qe_pin) { + pr_debug("%s: can't allocate memory\n", __func__); + return ERR_PTR(-ENOMEM); + } + + err = of_get_gpio(np, index); + if (err < 0) + goto err0; + gc = gpio_to_chip(err); + if (WARN_ON(!gc)) + goto err0; + + if (!of_device_is_compatible(gc->of_node, "fsl,mpc8323-qe-pario-bank")) { + pr_debug("%s: tried to get a non-qe pin\n", __func__); + err = -EINVAL; + goto err0; + } + + mm_gc = to_of_mm_gpio_chip(gc); + qe_gc = to_qe_gpio_chip(mm_gc); + + spin_lock_irqsave(&qe_gc->lock, flags); + + err -= gc->base; + if (test_and_set_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[err]) == 0) { + qe_pin->controller = qe_gc; + qe_pin->num = err; + err = 0; + } else { + err = -EBUSY; + } + + spin_unlock_irqrestore(&qe_gc->lock, flags); + + if (!err) + return qe_pin; +err0: + kfree(qe_pin); + pr_debug("%s failed with status %d\n", __func__, err); + return ERR_PTR(err); +} +EXPORT_SYMBOL(qe_pin_request); + +/** + * qe_pin_free - Free a pin + * @qe_pin: pointer to the qe_pin structure + * Context: any + * + * This function frees the qe_pin structure and makes a pin available + * for further qe_pin_request() calls. + */ +void qe_pin_free(struct qe_pin *qe_pin) +{ + struct qe_gpio_chip *qe_gc = qe_pin->controller; + unsigned long flags; + const int pin = qe_pin->num; + + spin_lock_irqsave(&qe_gc->lock, flags); + test_and_clear_bit(QE_PIN_REQUESTED, &qe_gc->pin_flags[pin]); + spin_unlock_irqrestore(&qe_gc->lock, flags); + + kfree(qe_pin); +} +EXPORT_SYMBOL(qe_pin_free); + +/** + * qe_pin_set_dedicated - Revert a pin to a dedicated peripheral function mode + * @qe_pin: pointer to the qe_pin structure + * Context: any + * + * This function resets a pin to a dedicated peripheral function that + * has been set up by the firmware. + */ +void qe_pin_set_dedicated(struct qe_pin *qe_pin) +{ + struct qe_gpio_chip *qe_gc = qe_pin->controller; + struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs; + struct qe_pio_regs *sregs = &qe_gc->saved_regs; + int pin = qe_pin->num; + u32 mask1 = 1 << (QE_PIO_PINS - (pin + 1)); + u32 mask2 = 0x3 << (QE_PIO_PINS - (pin % (QE_PIO_PINS / 2) + 1) * 2); + bool second_reg = pin > (QE_PIO_PINS / 2) - 1; + unsigned long flags; + + spin_lock_irqsave(&qe_gc->lock, flags); + + if (second_reg) { + clrsetbits_be32(®s->cpdir2, mask2, sregs->cpdir2 & mask2); + clrsetbits_be32(®s->cppar2, mask2, sregs->cppar2 & mask2); + } else { + clrsetbits_be32(®s->cpdir1, mask2, sregs->cpdir1 & mask2); + clrsetbits_be32(®s->cppar1, mask2, sregs->cppar1 & mask2); + } + + if (sregs->cpdata & mask1) + qe_gc->cpdata |= mask1; + else + qe_gc->cpdata &= ~mask1; + + out_be32(®s->cpdata, qe_gc->cpdata); + clrsetbits_be32(®s->cpodr, mask1, sregs->cpodr & mask1); + + spin_unlock_irqrestore(&qe_gc->lock, flags); +} +EXPORT_SYMBOL(qe_pin_set_dedicated); + +/** + * qe_pin_set_gpio - Set a pin to the GPIO mode + * @qe_pin: pointer to the qe_pin structure + * Context: any + * + * This function sets a pin to the GPIO mode. + */ +void qe_pin_set_gpio(struct qe_pin *qe_pin) +{ + struct qe_gpio_chip *qe_gc = qe_pin->controller; + struct qe_pio_regs __iomem *regs = qe_gc->mm_gc.regs; + unsigned long flags; + + spin_lock_irqsave(&qe_gc->lock, flags); + + /* Let's make it input by default, GPIO API is able to change that. */ + __par_io_config_pin(regs, qe_pin->num, QE_PIO_DIR_IN, 0, 0, 0); + + spin_unlock_irqrestore(&qe_gc->lock, flags); +} +EXPORT_SYMBOL(qe_pin_set_gpio); + +static int __init qe_add_gpiochips(void) +{ + struct device_node *np; + + for_each_compatible_node(np, NULL, "fsl,mpc8323-qe-pario-bank") { + int ret; + struct qe_gpio_chip *qe_gc; + struct of_mm_gpio_chip *mm_gc; + struct gpio_chip *gc; + + qe_gc = kzalloc(sizeof(*qe_gc), GFP_KERNEL); + if (!qe_gc) { + ret = -ENOMEM; + goto err; + } + + spin_lock_init(&qe_gc->lock); + + mm_gc = &qe_gc->mm_gc; + gc = &mm_gc->gc; + + mm_gc->save_regs = qe_gpio_save_regs; + gc->ngpio = QE_PIO_PINS; + gc->direction_input = qe_gpio_dir_in; + gc->direction_output = qe_gpio_dir_out; + gc->get = qe_gpio_get; + gc->set = qe_gpio_set; + + ret = of_mm_gpiochip_add(np, mm_gc); + if (ret) + goto err; + continue; +err: + pr_err("%s: registration failed with status %d\n", + np->full_name, ret); + kfree(qe_gc); + /* try others anyway */ + } + return 0; +} +arch_initcall(qe_add_gpiochips); |