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gpio-exar/8250-exar: Make set of exported GPIOs configurable
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On the SIMATIC, IOT2040 only a single pin is exportable as GPIO, the
rest is required to operate the UART. To allow modeling this case,
expand the platform device data structure to specify a (consecutive) pin
subset for exporting by the gpio-exar driver.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
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@jan-kiszka
jan-kiszka committed Jul 3, 2017
1 parent 277036f commit 380b1e2
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Showing 2 changed files with 45 additions and 26 deletions.
56 changes: 33 additions & 23 deletions drivers/gpio/gpio-exar.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@ struct exar_gpio_chip {
int index;
void __iomem *regs;
char name[20];
unsigned int first_pin;
};

static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
Expand All @@ -51,11 +52,12 @@ static void exar_update(struct gpio_chip *chip, unsigned int reg, int val,
static int exar_set_direction(struct gpio_chip *chip, int direction,
unsigned int offset)
{
unsigned int bank = offset / 8;
unsigned int addr;
struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
unsigned int bit = (offset + exar_gpio->first_pin) % 8;

addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
exar_update(chip, addr, direction, offset % 8);
exar_update(chip, addr, direction, bit);
return 0;
}

Expand All @@ -73,36 +75,33 @@ static int exar_get(struct gpio_chip *chip, unsigned int reg)

static int exar_get_direction(struct gpio_chip *chip, unsigned int offset)
{
unsigned int bank = offset / 8;
unsigned int addr;
int val;

addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
val = exar_get(chip, addr) & BIT(offset % 8);
struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO;
unsigned int bit = (offset + exar_gpio->first_pin) % 8;

return !!val;
return !!(exar_get(chip, addr) & BIT(bit));
}

static int exar_get_value(struct gpio_chip *chip, unsigned int offset)
{
unsigned int bank = offset / 8;
unsigned int addr;
int val;

addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
val = exar_get(chip, addr) & BIT(offset % 8);
struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
unsigned int bit = (offset + exar_gpio->first_pin) % 8;

return !!val;
return !!(exar_get(chip, addr) & BIT(bit));
}

static void exar_set_value(struct gpio_chip *chip, unsigned int offset,
int value)
{
unsigned int bank = offset / 8;
unsigned int addr;
struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip);
unsigned int addr = (offset + exar_gpio->first_pin) / 8 ?
EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
unsigned int bit = (offset + exar_gpio->first_pin) % 8;

addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO;
exar_update(chip, addr, value, offset % 8);
exar_update(chip, addr, value, bit);
}

static int exar_direction_output(struct gpio_chip *chip, unsigned int offset,
Expand All @@ -121,6 +120,7 @@ static int gpio_exar_probe(struct platform_device *pdev)
{
struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent);
struct exar_gpio_chip *exar_gpio;
u32 first_pin, ngpios;
void __iomem *p;
int index, ret;

Expand All @@ -132,6 +132,15 @@ static int gpio_exar_probe(struct platform_device *pdev)
if (!p)
return -ENOMEM;

ret = device_property_read_u32(&pdev->dev, "linux,first-pin",
&first_pin);
if (ret)
return ret;

ret = device_property_read_u32(&pdev->dev, "ngpios", &ngpios);
if (ret)
return ret;

exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL);
if (!exar_gpio)
return -ENOMEM;
Expand All @@ -149,9 +158,10 @@ static int gpio_exar_probe(struct platform_device *pdev)
exar_gpio->gpio_chip.get = exar_get_value;
exar_gpio->gpio_chip.set = exar_set_value;
exar_gpio->gpio_chip.base = -1;
exar_gpio->gpio_chip.ngpio = 16;
exar_gpio->gpio_chip.ngpio = ngpios;
exar_gpio->regs = p;
exar_gpio->index = index;
exar_gpio->first_pin = first_pin;

ret = devm_gpiochip_add_data(&pdev->dev,
&exar_gpio->gpio_chip, exar_gpio);
Expand Down
15 changes: 12 additions & 3 deletions drivers/tty/serial/8250/8250_exar.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -14,6 +14,7 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/property.h>
#include <linux/serial_core.h>
#include <linux/serial_reg.h>
#include <linux/slab.h>
Expand Down Expand Up @@ -194,7 +195,8 @@ static void setup_gpio(u8 __iomem *p)
}

static void *
__xr17v35x_register_gpio(struct pci_dev *pcidev)
__xr17v35x_register_gpio(struct pci_dev *pcidev,
const struct property_entry *properties)
{
struct platform_device *pdev;

Expand All @@ -205,20 +207,27 @@ __xr17v35x_register_gpio(struct pci_dev *pcidev)
pdev->dev.parent = &pcidev->dev;
ACPI_COMPANION_SET(&pdev->dev, ACPI_COMPANION(&pcidev->dev));

if (platform_device_add(pdev) < 0) {
if (platform_device_add_properties(pdev, properties) < 0 ||
platform_device_add(pdev) < 0) {
platform_device_put(pdev);
return NULL;
}

return pdev;
}

static const struct property_entry exar_gpio_properties[] = {
PROPERTY_ENTRY_U32("linux,first-pin", 0),
PROPERTY_ENTRY_U32("ngpios", 16),
{ }
};

static int xr17v35x_register_gpio(struct pci_dev *pcidev,
struct uart_8250_port *port)
{
if (pcidev->vendor == PCI_VENDOR_ID_EXAR)
port->port.private_data =
__xr17v35x_register_gpio(pcidev);
__xr17v35x_register_gpio(pcidev, exar_gpio_properties);

return 0;
}
Expand Down

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