diff options
Diffstat (limited to 'arch/powerpc/sysdev/qe_lib/gpio.c')
| -rw-r--r-- | arch/powerpc/sysdev/qe_lib/gpio.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/qe_lib/gpio.c b/arch/powerpc/sysdev/qe_lib/gpio.c index 8e5a0bc36d0..3485288dce3 100644 --- a/arch/powerpc/sysdev/qe_lib/gpio.c +++ b/arch/powerpc/sysdev/qe_lib/gpio.c @@ -14,6 +14,7 @@ #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> @@ -24,8 +25,14 @@ 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 * @@ -40,6 +47,12 @@ static void qe_gpio_save_regs(struct of_mm_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) @@ -103,6 +116,188 @@ static int qe_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val) 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 device_node *gc; + struct of_gpio_chip *of_gc = NULL; + struct of_mm_gpio_chip *mm_gc; + struct qe_gpio_chip *qe_gc; + int err; + int size; + const void *gpio_spec; + const u32 *gpio_cells; + 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_parse_phandles_with_args(np, "gpios", "#gpio-cells", index, + &gc, &gpio_spec); + if (err) { + pr_debug("%s: can't parse gpios property\n", __func__); + goto err0; + } + + if (!of_device_is_compatible(gc, "fsl,mpc8323-qe-pario-bank")) { + pr_debug("%s: tried to get a non-qe pin\n", __func__); + err = -EINVAL; + goto err1; + } + + of_gc = gc->data; + if (!of_gc) { + pr_debug("%s: gpio controller %s isn't registered\n", + np->full_name, gc->full_name); + err = -ENODEV; + goto err1; + } + + gpio_cells = of_get_property(gc, "#gpio-cells", &size); + if (!gpio_cells || size != sizeof(*gpio_cells) || + *gpio_cells != of_gc->gpio_cells) { + pr_debug("%s: wrong #gpio-cells for %s\n", + np->full_name, gc->full_name); + err = -EINVAL; + goto err1; + } + + err = of_gc->xlate(of_gc, np, gpio_spec, NULL); + if (err < 0) + goto err1; + + mm_gc = to_of_mm_gpio_chip(&of_gc->gc); + qe_gc = to_qe_gpio_chip(mm_gc); + + spin_lock_irqsave(&qe_gc->lock, flags); + + 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; +err1: + of_node_put(gc); +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; |