From 949506dc608f9820e0cee51b106c35fd3503bbb2 Mon Sep 17 00:00:00 2001 From: William Breathitt Gray Date: Wed, 20 Jul 2022 09:46:02 -0400 Subject: [PATCH] gpio: gpio-mm: Implement and utilize register structures Reduce magic numbers and improve code readability by implementing and utilizing named register data structures. The GPIO-MM device features an Intel 8255 compatible GPIO interface, so the i8255 GPIO module is selected and utilized as well. Tested-by: Fred Eckert Reviewed-by: Linus Walleij Signed-off-by: William Breathitt Gray Signed-off-by: Bartosz Golaszewski --- drivers/gpio/Kconfig | 1 + drivers/gpio/gpio-gpio-mm.c | 202 +++++++++----------------------------------- 2 files changed, 40 insertions(+), 163 deletions(-) diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 8f1d4d5..0642f57 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -886,6 +886,7 @@ config GPIO_GPIO_MM tristate "Diamond Systems GPIO-MM GPIO support" depends on PC104 select ISA_BUS_API + select GPIO_I8255 help Enables GPIO support for the Diamond Systems GPIO-MM and GPIO-MM-12. diff --git a/drivers/gpio/gpio-gpio-mm.c b/drivers/gpio/gpio-gpio-mm.c index 097a0646..2689671 100644 --- a/drivers/gpio/gpio-gpio-mm.c +++ b/drivers/gpio/gpio-gpio-mm.c @@ -6,8 +6,6 @@ * This driver supports the following Diamond Systems devices: GPIO-MM and * GPIO-MM-12. */ -#include -#include #include #include #include @@ -17,7 +15,10 @@ #include #include #include -#include + +#include "gpio-i8255.h" + +MODULE_IMPORT_NS(I8255); #define GPIOMM_EXTENT 8 #define MAX_NUM_GPIOMM max_num_isa_dev(GPIOMM_EXTENT) @@ -27,32 +28,26 @@ static unsigned int num_gpiomm; module_param_hw_array(base, uint, ioport, &num_gpiomm, 0); MODULE_PARM_DESC(base, "Diamond Systems GPIO-MM base addresses"); +#define GPIOMM_NUM_PPI 2 + /** * struct gpiomm_gpio - GPIO device private data structure - * @chip: instance of the gpio_chip - * @io_state: bit I/O state (whether bit is set to input or output) - * @out_state: output bits state - * @control: Control registers state - * @lock: synchronization lock to prevent I/O race conditions - * @base: base port address of the GPIO device + * @chip: instance of the gpio_chip + * @ppi_state: Programmable Peripheral Interface group states + * @ppi: Programmable Peripheral Interface groups */ struct gpiomm_gpio { struct gpio_chip chip; - unsigned char io_state[6]; - unsigned char out_state[6]; - unsigned char control[2]; - spinlock_t lock; - void __iomem *base; + struct i8255_state ppi_state[GPIOMM_NUM_PPI]; + struct i8255 __iomem *ppi; }; static int gpiomm_gpio_get_direction(struct gpio_chip *chip, unsigned int offset) { struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); - const unsigned int port = offset / 8; - const unsigned int mask = BIT(offset % 8); - if (gpiommgpio->io_state[port] & mask) + if (i8255_get_direction(gpiommgpio->ppi_state, offset)) return GPIO_LINE_DIRECTION_IN; return GPIO_LINE_DIRECTION_OUT; @@ -62,35 +57,8 @@ static int gpiomm_gpio_direction_input(struct gpio_chip *chip, unsigned int offset) { struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); - const unsigned int io_port = offset / 8; - const unsigned int control_port = io_port / 3; - unsigned long flags; - unsigned int control; - - spin_lock_irqsave(&gpiommgpio->lock, flags); - - /* Check if configuring Port C */ - if (io_port == 2 || io_port == 5) { - /* Port C can be configured by nibble */ - if (offset % 8 > 3) { - gpiommgpio->io_state[io_port] |= 0xF0; - gpiommgpio->control[control_port] |= BIT(3); - } else { - gpiommgpio->io_state[io_port] |= 0x0F; - gpiommgpio->control[control_port] |= BIT(0); - } - } else { - gpiommgpio->io_state[io_port] |= 0xFF; - if (io_port == 0 || io_port == 3) - gpiommgpio->control[control_port] |= BIT(4); - else - gpiommgpio->control[control_port] |= BIT(1); - } - control = BIT(7) | gpiommgpio->control[control_port]; - iowrite8(control, gpiommgpio->base + 3 + control_port*4); - - spin_unlock_irqrestore(&gpiommgpio->lock, flags); + i8255_direction_input(gpiommgpio->ppi, gpiommgpio->ppi_state, offset); return 0; } @@ -99,44 +67,9 @@ static int gpiomm_gpio_direction_output(struct gpio_chip *chip, unsigned int offset, int value) { struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); - const unsigned int io_port = offset / 8; - const unsigned int control_port = io_port / 3; - const unsigned int mask = BIT(offset % 8); - const unsigned int out_port = (io_port > 2) ? io_port + 1 : io_port; - unsigned long flags; - unsigned int control; - - spin_lock_irqsave(&gpiommgpio->lock, flags); - - /* Check if configuring Port C */ - if (io_port == 2 || io_port == 5) { - /* Port C can be configured by nibble */ - if (offset % 8 > 3) { - gpiommgpio->io_state[io_port] &= 0x0F; - gpiommgpio->control[control_port] &= ~BIT(3); - } else { - gpiommgpio->io_state[io_port] &= 0xF0; - gpiommgpio->control[control_port] &= ~BIT(0); - } - } else { - gpiommgpio->io_state[io_port] &= 0x00; - if (io_port == 0 || io_port == 3) - gpiommgpio->control[control_port] &= ~BIT(4); - else - gpiommgpio->control[control_port] &= ~BIT(1); - } - - if (value) - gpiommgpio->out_state[io_port] |= mask; - else - gpiommgpio->out_state[io_port] &= ~mask; - - control = BIT(7) | gpiommgpio->control[control_port]; - iowrite8(control, gpiommgpio->base + 3 + control_port*4); - iowrite8(gpiommgpio->out_state[io_port], gpiommgpio->base + out_port); - - spin_unlock_irqrestore(&gpiommgpio->lock, flags); + i8255_direction_output(gpiommgpio->ppi, gpiommgpio->ppi_state, offset, + value); return 0; } @@ -144,47 +77,16 @@ static int gpiomm_gpio_direction_output(struct gpio_chip *chip, static int gpiomm_gpio_get(struct gpio_chip *chip, unsigned int offset) { struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); - const unsigned int port = offset / 8; - const unsigned int mask = BIT(offset % 8); - const unsigned int in_port = (port > 2) ? port + 1 : port; - unsigned long flags; - unsigned int port_state; - - spin_lock_irqsave(&gpiommgpio->lock, flags); - - /* ensure that GPIO is set for input */ - if (!(gpiommgpio->io_state[port] & mask)) { - spin_unlock_irqrestore(&gpiommgpio->lock, flags); - return -EINVAL; - } - - port_state = ioread8(gpiommgpio->base + in_port); - - spin_unlock_irqrestore(&gpiommgpio->lock, flags); - return !!(port_state & mask); + return i8255_get(gpiommgpio->ppi, offset); } -static const size_t ports[] = { 0, 1, 2, 4, 5, 6 }; - static int gpiomm_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask, unsigned long *bits) { struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); - unsigned long offset; - unsigned long gpio_mask; - void __iomem *port_addr; - unsigned long port_state; - - /* clear bits array to a clean slate */ - bitmap_zero(bits, chip->ngpio); - for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) { - port_addr = gpiommgpio->base + ports[offset / 8]; - port_state = ioread8(port_addr) & gpio_mask; - - bitmap_set_value8(bits, port_state, offset); - } + i8255_get_multiple(gpiommgpio->ppi, mask, bits, chip->ngpio); return 0; } @@ -193,49 +95,17 @@ static void gpiomm_gpio_set(struct gpio_chip *chip, unsigned int offset, int value) { struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); - const unsigned int port = offset / 8; - const unsigned int mask = BIT(offset % 8); - const unsigned int out_port = (port > 2) ? port + 1 : port; - unsigned long flags; - - spin_lock_irqsave(&gpiommgpio->lock, flags); - - if (value) - gpiommgpio->out_state[port] |= mask; - else - gpiommgpio->out_state[port] &= ~mask; - - iowrite8(gpiommgpio->out_state[port], gpiommgpio->base + out_port); - spin_unlock_irqrestore(&gpiommgpio->lock, flags); + i8255_set(gpiommgpio->ppi, gpiommgpio->ppi_state, offset, value); } static void gpiomm_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask, unsigned long *bits) { struct gpiomm_gpio *const gpiommgpio = gpiochip_get_data(chip); - unsigned long offset; - unsigned long gpio_mask; - size_t index; - void __iomem *port_addr; - unsigned long bitmask; - unsigned long flags; - - for_each_set_clump8(offset, gpio_mask, mask, ARRAY_SIZE(ports) * 8) { - index = offset / 8; - port_addr = gpiommgpio->base + ports[index]; - - bitmask = bitmap_get_value8(bits, offset) & gpio_mask; - - spin_lock_irqsave(&gpiommgpio->lock, flags); - /* update output state data and set device gpio register */ - gpiommgpio->out_state[index] &= ~gpio_mask; - gpiommgpio->out_state[index] |= bitmask; - iowrite8(gpiommgpio->out_state[index], port_addr); - - spin_unlock_irqrestore(&gpiommgpio->lock, flags); - } + i8255_set_multiple(gpiommgpio->ppi, gpiommgpio->ppi_state, mask, bits, + chip->ngpio); } #define GPIOMM_NGPIO 48 @@ -250,6 +120,21 @@ static const char *gpiomm_names[GPIOMM_NGPIO] = { "Port 2C2", "Port 2C3", "Port 2C4", "Port 2C5", "Port 2C6", "Port 2C7", }; +static void gpiomm_init_dio(struct i8255 __iomem *const ppi, + struct i8255_state *const ppi_state) +{ + const unsigned long ngpio = 24; + const unsigned long mask = GENMASK(ngpio - 1, 0); + const unsigned long bits = 0; + unsigned long i; + + /* Initialize all GPIO to output 0 */ + for (i = 0; i < GPIOMM_NUM_PPI; i++) { + i8255_mode0_output(&ppi[i]); + i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio); + } +} + static int gpiomm_probe(struct device *dev, unsigned int id) { struct gpiomm_gpio *gpiommgpio; @@ -266,8 +151,8 @@ static int gpiomm_probe(struct device *dev, unsigned int id) return -EBUSY; } - gpiommgpio->base = devm_ioport_map(dev, base[id], GPIOMM_EXTENT); - if (!gpiommgpio->base) + gpiommgpio->ppi = devm_ioport_map(dev, base[id], GPIOMM_EXTENT); + if (!gpiommgpio->ppi) return -ENOMEM; gpiommgpio->chip.label = name; @@ -284,7 +169,8 @@ static int gpiomm_probe(struct device *dev, unsigned int id) gpiommgpio->chip.set = gpiomm_gpio_set; gpiommgpio->chip.set_multiple = gpiomm_gpio_set_multiple; - spin_lock_init(&gpiommgpio->lock); + i8255_state_init(gpiommgpio->ppi_state, GPIOMM_NUM_PPI); + gpiomm_init_dio(gpiommgpio->ppi, gpiommgpio->ppi_state); err = devm_gpiochip_add_data(dev, &gpiommgpio->chip, gpiommgpio); if (err) { @@ -292,16 +178,6 @@ static int gpiomm_probe(struct device *dev, unsigned int id) return err; } - /* initialize all GPIO as output */ - iowrite8(0x80, gpiommgpio->base + 3); - iowrite8(0x00, gpiommgpio->base); - iowrite8(0x00, gpiommgpio->base + 1); - iowrite8(0x00, gpiommgpio->base + 2); - iowrite8(0x80, gpiommgpio->base + 7); - iowrite8(0x00, gpiommgpio->base + 4); - iowrite8(0x00, gpiommgpio->base + 5); - iowrite8(0x00, gpiommgpio->base + 6); - return 0; } -- 2.7.4