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Message-Id: <761376c39a8f5d05199d4390a685fd3399943bfb.1658324498.git.william.gray@linaro.org>
Date: Wed, 20 Jul 2022 09:46:00 -0400
From: William Breathitt Gray <william.gray@...aro.org>
To: linus.walleij@...aro.org, brgl@...ev.pl
Cc: linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
William Breathitt Gray <william.gray@...aro.org>,
John Hentges <jhentges@...esio.com>,
Jay Dolan <jay.dolan@...esio.com>
Subject: [RESEND PATCH v4 4/6] gpio: 104-dio-48e: Implement and utilize register structures
Reduce magic numbers and improve code readability by implementing and
utilizing named register data structures. The 104-DIO-48E device
features an Intel 8255 compatible GPIO interface, so the i8255 GPIO
module is selected and utilized as well.
Reviewed-by: Linus Walleij <linus.walleij@...aro.org>
Cc: John Hentges <jhentges@...esio.com>
Cc: Jay Dolan <jay.dolan@...esio.com>
Signed-off-by: William Breathitt Gray <william.gray@...aro.org>
---
Changes in v4:
- Remove superfluous <linux/bitops.h> include
drivers/gpio/Kconfig | 1 +
drivers/gpio/gpio-104-dio-48e.c | 249 ++++++++++----------------------
2 files changed, 75 insertions(+), 175 deletions(-)
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index df484b72000d..d070bd9f4f94 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -841,6 +841,7 @@ config GPIO_104_DIO_48E
depends on PC104
select ISA_BUS_API
select GPIOLIB_IRQCHIP
+ select GPIO_I8255
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 f118ad9bcd33..a41551870759 100644
--- a/drivers/gpio/gpio-104-dio-48e.c
+++ b/drivers/gpio/gpio-104-dio-48e.c
@@ -6,8 +6,7 @@
* This driver supports the following ACCES devices: 104-DIO-48E and
* 104-DIO-24E.
*/
-#include <linux/bitmap.h>
-#include <linux/bitops.h>
+#include <linux/bits.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/gpio/driver.h>
@@ -20,6 +19,11 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/spinlock.h>
+#include <linux/types.h>
+
+#include "gpio-i8255.h"
+
+MODULE_IMPORT_NS(I8255);
#define DIO48E_EXTENT 16
#define MAX_NUM_DIO48E max_num_isa_dev(DIO48E_EXTENT)
@@ -33,34 +37,54 @@ static unsigned int irq[MAX_NUM_DIO48E];
module_param_hw_array(irq, uint, irq, NULL, 0);
MODULE_PARM_DESC(irq, "ACCES 104-DIO-48E interrupt line numbers");
+#define DIO48E_NUM_PPI 2
+
+/**
+ * struct dio48e_reg - device register structure
+ * @ppi: Programmable Peripheral Interface groups
+ * @enable_buffer: Enable/Disable Buffer groups
+ * @unused1: Unused
+ * @enable_interrupt: Write: Enable Interrupt
+ * Read: Disable Interrupt
+ * @unused2: Unused
+ * @enable_counter: Write: Enable Counter/Timer Addressing
+ * Read: Disable Counter/Timer Addressing
+ * @unused3: Unused
+ * @clear_interrupt: Clear Interrupt
+ */
+struct dio48e_reg {
+ struct i8255 ppi[DIO48E_NUM_PPI];
+ u8 enable_buffer[DIO48E_NUM_PPI];
+ u8 unused1;
+ u8 enable_interrupt;
+ u8 unused2;
+ u8 enable_counter;
+ u8 unused3;
+ u8 clear_interrupt;
+};
+
/**
* struct dio48e_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
- * @irq_mask: I/O bits affected by interrupts
+ * @chip: instance of the gpio_chip
+ * @ppi_state: PPI device states
+ * @lock: synchronization lock to prevent I/O race conditions
+ * @reg: I/O address offset for the device registers
+ * @irq_mask: I/O bits affected by interrupts
*/
struct dio48e_gpio {
struct gpio_chip chip;
- unsigned char io_state[6];
- unsigned char out_state[6];
- unsigned char control[2];
+ struct i8255_state ppi_state[DIO48E_NUM_PPI];
raw_spinlock_t lock;
- void __iomem *base;
+ struct dio48e_reg __iomem *reg;
unsigned char irq_mask;
};
static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
- const unsigned int port = offset / 8;
- const unsigned int mask = BIT(offset % 8);
- if (dio48egpio->io_state[port] & mask)
- return GPIO_LINE_DIRECTION_IN;
+ if (i8255_get_direction(dio48egpio->ppi_state, offset))
+ return GPIO_LINE_DIRECTION_IN;
return GPIO_LINE_DIRECTION_OUT;
}
@@ -68,38 +92,9 @@ static int dio48e_gpio_get_direction(struct gpio_chip *chip, unsigned int offset
static int dio48e_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
{
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(chip);
- const unsigned int io_port = offset / 8;
- const unsigned int control_port = io_port / 3;
- void __iomem *const control_addr = dio48egpio->base + 3 + control_port * 4;
- unsigned long flags;
- unsigned int control;
-
- raw_spin_lock_irqsave(&dio48egpio->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) {
- dio48egpio->io_state[io_port] |= 0xF0;
- dio48egpio->control[control_port] |= BIT(3);
- } else {
- dio48egpio->io_state[io_port] |= 0x0F;
- dio48egpio->control[control_port] |= BIT(0);
- }
- } else {
- dio48egpio->io_state[io_port] |= 0xFF;
- if (io_port == 0 || io_port == 3)
- dio48egpio->control[control_port] |= BIT(4);
- else
- dio48egpio->control[control_port] |= BIT(1);
- }
-
- control = BIT(7) | dio48egpio->control[control_port];
- iowrite8(control, control_addr);
- control &= ~BIT(7);
- iowrite8(control, control_addr);
-
- raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
+ i8255_direction_input(dio48egpio->reg->ppi, dio48egpio->ppi_state,
+ offset);
return 0;
}
@@ -108,48 +103,9 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned int off
int value)
{
struct dio48e_gpio *const dio48egpio = 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);
- void __iomem *const control_addr = dio48egpio->base + 3 + control_port * 4;
- const unsigned int out_port = (io_port > 2) ? io_port + 1 : io_port;
- unsigned long flags;
- unsigned int control;
-
- raw_spin_lock_irqsave(&dio48egpio->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) {
- dio48egpio->io_state[io_port] &= 0x0F;
- dio48egpio->control[control_port] &= ~BIT(3);
- } else {
- dio48egpio->io_state[io_port] &= 0xF0;
- dio48egpio->control[control_port] &= ~BIT(0);
- }
- } else {
- dio48egpio->io_state[io_port] &= 0x00;
- if (io_port == 0 || io_port == 3)
- dio48egpio->control[control_port] &= ~BIT(4);
- else
- dio48egpio->control[control_port] &= ~BIT(1);
- }
-
- if (value)
- dio48egpio->out_state[io_port] |= mask;
- else
- dio48egpio->out_state[io_port] &= ~mask;
- control = BIT(7) | dio48egpio->control[control_port];
- iowrite8(control, control_addr);
-
- iowrite8(dio48egpio->out_state[io_port], dio48egpio->base + out_port);
-
- control &= ~BIT(7);
- iowrite8(control, control_addr);
-
- raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
+ i8255_direction_output(dio48egpio->reg->ppi, dio48egpio->ppi_state,
+ offset, value);
return 0;
}
@@ -157,47 +113,16 @@ static int dio48e_gpio_direction_output(struct gpio_chip *chip, unsigned int off
static int dio48e_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct dio48e_gpio *const dio48egpio = 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;
-
- raw_spin_lock_irqsave(&dio48egpio->lock, flags);
- /* ensure that GPIO is set for input */
- if (!(dio48egpio->io_state[port] & mask)) {
- raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
- return -EINVAL;
- }
-
- port_state = ioread8(dio48egpio->base + in_port);
-
- raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
-
- return !!(port_state & mask);
+ return i8255_get(dio48egpio->reg->ppi, offset);
}
-static const size_t ports[] = { 0, 1, 2, 4, 5, 6 };
-
static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
unsigned long *bits)
{
struct dio48e_gpio *const dio48egpio = 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 = dio48egpio->base + ports[offset / 8];
- port_state = ioread8(port_addr) & gpio_mask;
-
- bitmap_set_value8(bits, port_state, offset);
- }
+ i8255_get_multiple(dio48egpio->reg->ppi, mask, bits, chip->ngpio);
return 0;
}
@@ -205,49 +130,17 @@ static int dio48e_gpio_get_multiple(struct gpio_chip *chip, unsigned long *mask,
static void dio48e_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
{
struct dio48e_gpio *const dio48egpio = 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;
- raw_spin_lock_irqsave(&dio48egpio->lock, flags);
-
- if (value)
- dio48egpio->out_state[port] |= mask;
- else
- dio48egpio->out_state[port] &= ~mask;
-
- iowrite8(dio48egpio->out_state[port], dio48egpio->base + out_port);
-
- raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
+ i8255_set(dio48egpio->reg->ppi, dio48egpio->ppi_state, offset, value);
}
static void dio48e_gpio_set_multiple(struct gpio_chip *chip,
unsigned long *mask, unsigned long *bits)
{
struct dio48e_gpio *const dio48egpio = 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 = dio48egpio->base + ports[index];
-
- bitmask = bitmap_get_value8(bits, offset) & gpio_mask;
-
- raw_spin_lock_irqsave(&dio48egpio->lock, flags);
- /* update output state data and set device gpio register */
- dio48egpio->out_state[index] &= ~gpio_mask;
- dio48egpio->out_state[index] |= bitmask;
- iowrite8(dio48egpio->out_state[index], port_addr);
-
- raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
- }
+ i8255_set_multiple(dio48egpio->reg->ppi, dio48egpio->ppi_state, mask,
+ bits, chip->ngpio);
}
static void dio48e_irq_ack(struct irq_data *data)
@@ -274,7 +167,7 @@ static void dio48e_irq_mask(struct irq_data *data)
if (!dio48egpio->irq_mask)
/* disable interrupts */
- ioread8(dio48egpio->base + 0xB);
+ ioread8(&dio48egpio->reg->enable_interrupt);
raw_spin_unlock_irqrestore(&dio48egpio->lock, flags);
}
@@ -294,8 +187,8 @@ static void dio48e_irq_unmask(struct irq_data *data)
if (!dio48egpio->irq_mask) {
/* enable interrupts */
- iowrite8(0x00, dio48egpio->base + 0xF);
- iowrite8(0x00, dio48egpio->base + 0xB);
+ iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
+ iowrite8(0x00, &dio48egpio->reg->enable_interrupt);
}
if (offset == 19)
@@ -341,7 +234,7 @@ static irqreturn_t dio48e_irq_handler(int irq, void *dev_id)
raw_spin_lock(&dio48egpio->lock);
- iowrite8(0x00, dio48egpio->base + 0xF);
+ iowrite8(0x00, &dio48egpio->reg->clear_interrupt);
raw_spin_unlock(&dio48egpio->lock);
@@ -373,11 +266,26 @@ static int dio48e_irq_init_hw(struct gpio_chip *gc)
struct dio48e_gpio *const dio48egpio = gpiochip_get_data(gc);
/* Disable IRQ by default */
- ioread8(dio48egpio->base + 0xB);
+ ioread8(&dio48egpio->reg->enable_interrupt);
return 0;
}
+static void dio48e_init_ppi(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 < DIO48E_NUM_PPI; i++) {
+ i8255_mode0_output(&ppi[i]);
+ i8255_set_multiple(&ppi[i], &ppi_state[i], &mask, &bits, ngpio);
+ }
+}
+
static int dio48e_probe(struct device *dev, unsigned int id)
{
struct dio48e_gpio *dio48egpio;
@@ -395,8 +303,8 @@ static int dio48e_probe(struct device *dev, unsigned int id)
return -EBUSY;
}
- dio48egpio->base = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
- if (!dio48egpio->base)
+ dio48egpio->reg = devm_ioport_map(dev, base[id], DIO48E_EXTENT);
+ if (!dio48egpio->reg)
return -ENOMEM;
dio48egpio->chip.label = name;
@@ -425,17 +333,8 @@ static int dio48e_probe(struct device *dev, unsigned int id)
raw_spin_lock_init(&dio48egpio->lock);
- /* initialize all GPIO as output */
- iowrite8(0x80, dio48egpio->base + 3);
- iowrite8(0x00, dio48egpio->base);
- iowrite8(0x00, dio48egpio->base + 1);
- iowrite8(0x00, dio48egpio->base + 2);
- iowrite8(0x00, dio48egpio->base + 3);
- iowrite8(0x80, dio48egpio->base + 7);
- iowrite8(0x00, dio48egpio->base + 4);
- iowrite8(0x00, dio48egpio->base + 5);
- iowrite8(0x00, dio48egpio->base + 6);
- iowrite8(0x00, dio48egpio->base + 7);
+ i8255_state_init(dio48egpio->ppi_state, DIO48E_NUM_PPI);
+ dio48e_init_ppi(dio48egpio->reg->ppi, dio48egpio->ppi_state);
err = devm_gpiochip_add_data(dev, &dio48egpio->chip, dio48egpio);
if (err) {
--
2.36.1
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