From 92f7a35836c2e13ae5f0dc8c7f889e92f66a9d19 Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Thu, 20 Jul 2023 14:49:43 -0400 Subject: [PATCH] gpio: 104-dio-48e: Add Counter/Timer support The 104-DIO-48E features an 8254 Counter/Timer chip providing three counter/timers which can be used for frequency measurement, frequency output, pulse width modulation, pulse width measurement, event count, etc. The counter/timers use the same addresses as PPI 0 (addresses 0x0 to 0x3), so a raw_spinlock_t is used to synchronize operations between the two regmap mappings to prevent clobbering. Reviewed-by: Linus Walleij Signed-off-by: William Breathitt Gray Signed-off-by: Bartosz Golaszewski --- drivers/gpio/Kconfig | 1 + drivers/gpio/gpio-104-dio-48e.c | 127 +++++++++++++++++++++++++++++++++++----- 2 files changed, 112 insertions(+), 16 deletions(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 8b41893..61a8d07 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -858,6 +858,7 @@ config GPIO_104_DIO_48E select REGMAP_IRQ select GPIOLIB_IRQCHIP select GPIO_I8255 + select I8254 help Enables GPIO support for the ACCES 104-DIO-48E series (104-DIO-48E, 104-DIO-24E). The base port addresses for the devices may be diff --git a/drivers/gpio/gpio-104-dio-48e.c b/drivers/gpio/gpio-104-dio-48e.c index 8ff5f4ff..4df9bec 100644 --- a/drivers/gpio/gpio-104-dio-48e.c +++ b/drivers/gpio/gpio-104-dio-48e.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -16,6 +17,7 @@ #include #include #include +#include #include #include "gpio-i8255.h" @@ -37,6 +39,8 @@ MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers"); #define DIO48E_ENABLE_INTERRUPT 0xB #define DIO48E_DISABLE_INTERRUPT DIO48E_ENABLE_INTERRUPT +#define DIO48E_ENABLE_COUNTER_TIMER_ADDRESSING 0xD +#define DIO48E_DISABLE_COUNTER_TIMER_ADDRESSING DIO48E_ENABLE_COUNTER_TIMER_ADDRESSING #define DIO48E_CLEAR_INTERRUPT 0xF #define DIO48E_NUM_PPI 2 @@ -75,18 +79,20 @@ static const struct regmap_access_table dio48e_precious_table = { .yes_ranges = dio48e_precious_ranges, .n_yes_ranges = ARRAY_SIZE(dio48e_precious_ranges), }; -static const struct regmap_config dio48e_regmap_config = { - .reg_bits = 8, - .reg_stride = 1, - .val_bits = 8, - .io_port = true, - .max_register = 0xF, - .wr_table = &dio48e_wr_table, - .rd_table = &dio48e_rd_table, - .volatile_table = &dio48e_volatile_table, - .precious_table = &dio48e_precious_table, - .cache_type = REGCACHE_FLAT, - .use_raw_spinlock = true, + +static const struct regmap_range pit_wr_ranges[] = { + regmap_reg_range(0x0, 0x3), +}; +static const struct regmap_range pit_rd_ranges[] = { + regmap_reg_range(0x0, 0x2), +}; +static const struct regmap_access_table pit_wr_table = { + .yes_ranges = pit_wr_ranges, + .n_yes_ranges = ARRAY_SIZE(pit_wr_ranges), +}; +static const struct regmap_access_table pit_rd_table = { + .yes_ranges = pit_rd_ranges, + .n_yes_ranges = ARRAY_SIZE(pit_rd_ranges), }; /* only bit 3 on each respective Port C supports interrupts */ @@ -102,14 +108,56 @@ static const struct regmap_irq dio48e_regmap_irqs[] = { /** * struct dio48e_gpio - GPIO device private data structure + * @lock: synchronization lock to prevent I/O race conditions * @map: Regmap for the device + * @regs: virtual mapping for device registers + * @flags: IRQ flags saved during locking * @irq_mask: Current IRQ mask state on the device */ struct dio48e_gpio { + raw_spinlock_t lock; struct regmap *map; + void __iomem *regs; + unsigned long flags; unsigned int irq_mask; }; +static void dio48e_regmap_lock(void *lock_arg) __acquires(&dio48egpio->lock) +{ + struct dio48e_gpio *const dio48egpio = lock_arg; + unsigned long flags; + + raw_spin_lock_irqsave(&dio48egpio->lock, flags); + dio48egpio->flags = flags; +} + +static void dio48e_regmap_unlock(void *lock_arg) __releases(&dio48egpio->lock) +{ + struct dio48e_gpio *const dio48egpio = lock_arg; + + raw_spin_unlock_irqrestore(&dio48egpio->lock, dio48egpio->flags); +} + +static void pit_regmap_lock(void *lock_arg) __acquires(&dio48egpio->lock) +{ + struct dio48e_gpio *const dio48egpio = lock_arg; + unsigned long flags; + + raw_spin_lock_irqsave(&dio48egpio->lock, flags); + dio48egpio->flags = flags; + + iowrite8(0x00, dio48egpio->regs + DIO48E_ENABLE_COUNTER_TIMER_ADDRESSING); +} + +static void pit_regmap_unlock(void *lock_arg) __releases(&dio48egpio->lock) +{ + struct dio48e_gpio *const dio48egpio = lock_arg; + + ioread8(dio48egpio->regs + DIO48E_DISABLE_COUNTER_TIMER_ADDRESSING); + + raw_spin_unlock_irqrestore(&dio48egpio->lock, dio48egpio->flags); +} + static int dio48e_handle_mask_sync(const int index, const unsigned int mask_buf_def, const unsigned int mask_buf, @@ -176,6 +224,9 @@ static int dio48e_probe(struct device *dev, unsigned int id) struct i8255_regmap_config config = {}; void __iomem *regs; struct regmap *map; + struct regmap_config dio48e_regmap_config; + struct regmap_config pit_regmap_config; + struct i8254_regmap_config pit_config; int err; struct regmap_irq_chip *chip; struct dio48e_gpio *dio48egpio; @@ -187,21 +238,58 @@ static int dio48e_probe(struct device *dev, unsigned int id) return -EBUSY; } + dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL); + if (!dio48egpio) + return -ENOMEM; + regs = devm_ioport_map(dev, base[id], DIO48E_EXTENT); if (!regs) return -ENOMEM; + dio48egpio->regs = regs; + + raw_spin_lock_init(&dio48egpio->lock); + + dio48e_regmap_config = (struct regmap_config) { + .reg_bits = 8, + .reg_stride = 1, + .val_bits = 8, + .lock = dio48e_regmap_lock, + .unlock = dio48e_regmap_unlock, + .lock_arg = dio48egpio, + .io_port = true, + .wr_table = &dio48e_wr_table, + .rd_table = &dio48e_rd_table, + .volatile_table = &dio48e_volatile_table, + .precious_table = &dio48e_precious_table, + .cache_type = REGCACHE_FLAT, + }; + map = devm_regmap_init_mmio(dev, regs, &dio48e_regmap_config); if (IS_ERR(map)) return dev_err_probe(dev, PTR_ERR(map), "Unable to initialize register map\n"); - dio48egpio = devm_kzalloc(dev, sizeof(*dio48egpio), GFP_KERNEL); - if (!dio48egpio) - return -ENOMEM; - dio48egpio->map = map; + pit_regmap_config = (struct regmap_config) { + .name = "i8254", + .reg_bits = 8, + .reg_stride = 1, + .val_bits = 8, + .lock = pit_regmap_lock, + .unlock = pit_regmap_unlock, + .lock_arg = dio48egpio, + .io_port = true, + .wr_table = &pit_wr_table, + .rd_table = &pit_rd_table, + }; + + pit_config.map = devm_regmap_init_mmio(dev, regs, &pit_regmap_config); + if (IS_ERR(pit_config.map)) + return dev_err_probe(dev, PTR_ERR(pit_config.map), + "Unable to initialize i8254 register map\n"); + chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; @@ -225,6 +313,12 @@ static int dio48e_probe(struct device *dev, unsigned int id) if (err) return dev_err_probe(dev, err, "IRQ registration failed\n"); + pit_config.parent = dev; + + err = devm_i8254_regmap_register(dev, &pit_config); + if (err) + return err; + config.parent = dev; config.map = map; config.num_ppi = DIO48E_NUM_PPI; @@ -245,3 +339,4 @@ module_isa_driver_with_irq(dio48e_driver, num_dio48e, num_irq); MODULE_AUTHOR("William Breathitt Gray "); MODULE_DESCRIPTION("ACCES 104-DIO-48E GPIO driver"); MODULE_LICENSE("GPL v2"); +MODULE_IMPORT_NS(I8254); -- 2.7.4