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misc: microchip: pci1xxxx: Add functions to configure gpio pins as input / output, get status, handle I/O for gpio pins.

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direction_input and direction_output functions configures a gpio pin as
input and output respectively. get_direction function returns if a gpio
pin is output or input. get function returns the value of a gpio pin
whereas set function assigns output value for a gpio pin.

Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Link: https://lore.kernel.org/r/20220824200047.150308-4-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Kumaravel Thiagarajan 2022-08-25 01:30:45 +05:30 committed by Greg Kroah-Hartman
parent 7d3e4d807d
commit 9b91a368a4
1 changed files with 79 additions and 0 deletions
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79
drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gpio.c
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@ -13,6 +13,10 @@
#include "mchp_pci1xxxx_gp.h"
#define PCI1XXXX_NR_PINS 93
#define OUT_EN_OFFSET(x) ((((x) / 32) * 4) + 0x400)
#define INP_EN_OFFSET(x) ((((x) / 32) * 4) + 0x400 + 0x10)
#define OUT_OFFSET(x) ((((x) / 32) * 4) + 0x400 + 0x20)
#define INP_OFFSET(x) ((((x) / 32) * 4) + 0x400 + 0x30)
#define PULLUP_OFFSET(x) ((((x) / 32) * 4) + 0x400 + 0x40)
#define PULLDOWN_OFFSET(x) ((((x) / 32) * 4) + 0x400 + 0x50)
#define OPENDRAIN_OFFSET(x) ((((x) / 32) * 4) + 0x400 + 0x60)
@ -30,6 +34,24 @@ struct pci1xxxx_gpio {
int irq_base;
};
static int pci1xxxx_gpio_get_direction(struct gpio_chip *gpio, unsigned int nr)
{
struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
u32 data;
int ret = -EINVAL;
data = readl(priv->reg_base + INP_EN_OFFSET(nr));
if (data & BIT(nr % 32)) {
ret = 1;
} else {
data = readl(priv->reg_base + OUT_EN_OFFSET(nr));
if (data & BIT(nr % 32))
ret = 0;
}
return ret;
}
static inline void pci1xxx_assign_bit(void __iomem *base_addr, unsigned int reg_offset,
unsigned int bitpos, bool set)
{
@ -43,6 +65,58 @@ static inline void pci1xxx_assign_bit(void __iomem *base_addr, unsigned int reg_
writel(data, base_addr + reg_offset);
}
static int pci1xxxx_gpio_direction_input(struct gpio_chip *gpio, unsigned int nr)
{
struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
pci1xxx_assign_bit(priv->reg_base, INP_EN_OFFSET(nr), (nr % 32), true);
pci1xxx_assign_bit(priv->reg_base, OUT_EN_OFFSET(nr), (nr % 32), false);
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int pci1xxxx_gpio_get(struct gpio_chip *gpio, unsigned int nr)
{
struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
return (readl(priv->reg_base + INP_OFFSET(nr)) >> (nr % 32)) & 1;
}
static int pci1xxxx_gpio_direction_output(struct gpio_chip *gpio,
unsigned int nr, int val)
{
struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
unsigned long flags;
u32 data;
spin_lock_irqsave(&priv->lock, flags);
pci1xxx_assign_bit(priv->reg_base, INP_EN_OFFSET(nr), (nr % 32), false);
pci1xxx_assign_bit(priv->reg_base, OUT_EN_OFFSET(nr), (nr % 32), true);
data = readl(priv->reg_base + OUT_OFFSET(nr));
if (val)
data |= (1 << (nr % 32));
else
data &= ~(1 << (nr % 32));
writel(data, priv->reg_base + OUT_OFFSET(nr));
spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static void pci1xxxx_gpio_set(struct gpio_chip *gpio,
unsigned int nr, int val)
{
struct pci1xxxx_gpio *priv = gpiochip_get_data(gpio);
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
pci1xxx_assign_bit(priv->reg_base, OUT_OFFSET(nr), (nr % 32), val);
spin_unlock_irqrestore(&priv->lock, flags);
}
static int pci1xxxx_gpio_set_config(struct gpio_chip *gpio, unsigned int offset,
unsigned long config)
{
@ -81,6 +155,11 @@ static int pci1xxxx_gpio_setup(struct pci1xxxx_gpio *priv, int irq)
gchip->label = dev_name(&priv->aux_dev->dev);
gchip->parent = &priv->aux_dev->dev;
gchip->owner = THIS_MODULE;
gchip->direction_input = pci1xxxx_gpio_direction_input;
gchip->direction_output = pci1xxxx_gpio_direction_output;
gchip->get_direction = pci1xxxx_gpio_get_direction;
gchip->get = pci1xxxx_gpio_get;
gchip->set = pci1xxxx_gpio_set;
gchip->set_config = pci1xxxx_gpio_set_config;
gchip->dbg_show = NULL;
gchip->base = -1;