diff options
Diffstat (limited to 'drivers/gpio/gpio-idio-16.c')
| -rw-r--r-- | drivers/gpio/gpio-idio-16.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-idio-16.c b/drivers/gpio/gpio-idio-16.c new file mode 100644 index 000000000000..13315242d220 --- /dev/null +++ b/drivers/gpio/gpio-idio-16.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * GPIO library for the ACCES IDIO-16 family + * Copyright (C) 2022 William Breathitt Gray + */ +#include <linux/bitmap.h> +#include <linux/export.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include "gpio-idio-16.h" + +#define DEFAULT_SYMBOL_NAMESPACE GPIO_IDIO_16 + +/** + * idio_16_get - get signal value at signal offset + * @reg: ACCES IDIO-16 device registers + * @state: ACCES IDIO-16 device state + * @offset: offset of signal to get + * + * Returns the signal value (0=low, 1=high) for the signal at @offset. + */ +int idio_16_get(struct idio_16 __iomem *const reg, + struct idio_16_state *const state, const unsigned long offset) +{ + const unsigned long mask = BIT(offset); + + if (offset < IDIO_16_NOUT) + return test_bit(offset, state->out_state); + + if (offset < 24) + return !!(ioread8(®->in0_7) & (mask >> IDIO_16_NOUT)); + + if (offset < 32) + return !!(ioread8(®->in8_15) & (mask >> 24)); + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(idio_16_get); + +/** + * idio_16_get_multiple - get multiple signal values at multiple signal offsets + * @reg: ACCES IDIO-16 device registers + * @state: ACCES IDIO-16 device state + * @mask: mask of signals to get + * @bits: bitmap to store signal values + * + * Stores in @bits the values (0=low, 1=high) for the signals defined by @mask. + */ +void idio_16_get_multiple(struct idio_16 __iomem *const reg, + struct idio_16_state *const state, + const unsigned long *const mask, + unsigned long *const bits) +{ + unsigned long flags; + const unsigned long out_mask = GENMASK(IDIO_16_NOUT - 1, 0); + + spin_lock_irqsave(&state->lock, flags); + + bitmap_replace(bits, bits, state->out_state, &out_mask, IDIO_16_NOUT); + if (*mask & GENMASK(23, 16)) + bitmap_set_value8(bits, ioread8(®->in0_7), 16); + if (*mask & GENMASK(31, 24)) + bitmap_set_value8(bits, ioread8(®->in8_15), 24); + + spin_unlock_irqrestore(&state->lock, flags); +} +EXPORT_SYMBOL_GPL(idio_16_get_multiple); + +/** + * idio_16_set - set signal value at signal offset + * @reg: ACCES IDIO-16 device registers + * @state: ACCES IDIO-16 device state + * @offset: offset of signal to set + * @value: value of signal to set + * + * Assigns output @value for the signal at @offset. + */ +void idio_16_set(struct idio_16 __iomem *const reg, + struct idio_16_state *const state, const unsigned long offset, + const unsigned long value) +{ + unsigned long flags; + + if (offset >= IDIO_16_NOUT) + return; + + spin_lock_irqsave(&state->lock, flags); + + __assign_bit(offset, state->out_state, value); + if (offset < 8) + iowrite8(bitmap_get_value8(state->out_state, 0), ®->out0_7); + else + iowrite8(bitmap_get_value8(state->out_state, 8), ®->out8_15); + + spin_unlock_irqrestore(&state->lock, flags); +} +EXPORT_SYMBOL_GPL(idio_16_set); + +/** + * idio_16_set_multiple - set signal values at multiple signal offsets + * @reg: ACCES IDIO-16 device registers + * @state: ACCES IDIO-16 device state + * @mask: mask of signals to set + * @bits: bitmap of signal output values + * + * Assigns output values defined by @bits for the signals defined by @mask. + */ +void idio_16_set_multiple(struct idio_16 __iomem *const reg, + struct idio_16_state *const state, + const unsigned long *const mask, + const unsigned long *const bits) +{ + unsigned long flags; + + spin_lock_irqsave(&state->lock, flags); + + bitmap_replace(state->out_state, state->out_state, bits, mask, + IDIO_16_NOUT); + if (*mask & GENMASK(7, 0)) + iowrite8(bitmap_get_value8(state->out_state, 0), ®->out0_7); + if (*mask & GENMASK(15, 8)) + iowrite8(bitmap_get_value8(state->out_state, 8), ®->out8_15); + + spin_unlock_irqrestore(&state->lock, flags); +} +EXPORT_SYMBOL_GPL(idio_16_set_multiple); + +/** + * idio_16_state_init - initialize idio_16_state structure + * @state: ACCES IDIO-16 device state + * + * Initializes the ACCES IDIO-16 device @state for use in idio-16 library + * functions. + */ +void idio_16_state_init(struct idio_16_state *const state) +{ + spin_lock_init(&state->lock); +} +EXPORT_SYMBOL_GPL(idio_16_state_init); + +MODULE_AUTHOR("William Breathitt Gray"); +MODULE_DESCRIPTION("ACCES IDIO-16 GPIO Library"); +MODULE_LICENSE("GPL"); |