forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
200 lines
4.3 KiB
200 lines
4.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* |
|
* Janz MODULbus VMOD-TTL GPIO Driver |
|
* |
|
* Copyright (c) 2010 Ira W. Snyder <[email protected]> |
|
*/ |
|
|
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/init.h> |
|
#include <linux/interrupt.h> |
|
#include <linux/delay.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/io.h> |
|
#include <linux/gpio/driver.h> |
|
#include <linux/slab.h> |
|
#include <linux/bitops.h> |
|
|
|
#include <linux/mfd/janz.h> |
|
|
|
#define DRV_NAME "janz-ttl" |
|
|
|
#define PORTA_DIRECTION 0x23 |
|
#define PORTB_DIRECTION 0x2B |
|
#define PORTC_DIRECTION 0x06 |
|
#define PORTA_IOCTL 0x24 |
|
#define PORTB_IOCTL 0x2C |
|
#define PORTC_IOCTL 0x07 |
|
|
|
#define MASTER_INT_CTL 0x00 |
|
#define MASTER_CONF_CTL 0x01 |
|
|
|
#define CONF_PAE BIT(2) |
|
#define CONF_PBE BIT(7) |
|
#define CONF_PCE BIT(4) |
|
|
|
struct ttl_control_regs { |
|
__be16 portc; |
|
__be16 portb; |
|
__be16 porta; |
|
__be16 control; |
|
}; |
|
|
|
struct ttl_module { |
|
struct gpio_chip gpio; |
|
|
|
/* base address of registers */ |
|
struct ttl_control_regs __iomem *regs; |
|
|
|
u8 portc_shadow; |
|
u8 portb_shadow; |
|
u8 porta_shadow; |
|
|
|
spinlock_t lock; |
|
}; |
|
|
|
static int ttl_get_value(struct gpio_chip *gpio, unsigned offset) |
|
{ |
|
struct ttl_module *mod = dev_get_drvdata(gpio->parent); |
|
u8 *shadow; |
|
int ret; |
|
|
|
if (offset < 8) { |
|
shadow = &mod->porta_shadow; |
|
} else if (offset < 16) { |
|
shadow = &mod->portb_shadow; |
|
offset -= 8; |
|
} else { |
|
shadow = &mod->portc_shadow; |
|
offset -= 16; |
|
} |
|
|
|
spin_lock(&mod->lock); |
|
ret = *shadow & BIT(offset); |
|
spin_unlock(&mod->lock); |
|
return !!ret; |
|
} |
|
|
|
static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value) |
|
{ |
|
struct ttl_module *mod = dev_get_drvdata(gpio->parent); |
|
void __iomem *port; |
|
u8 *shadow; |
|
|
|
if (offset < 8) { |
|
port = &mod->regs->porta; |
|
shadow = &mod->porta_shadow; |
|
} else if (offset < 16) { |
|
port = &mod->regs->portb; |
|
shadow = &mod->portb_shadow; |
|
offset -= 8; |
|
} else { |
|
port = &mod->regs->portc; |
|
shadow = &mod->portc_shadow; |
|
offset -= 16; |
|
} |
|
|
|
spin_lock(&mod->lock); |
|
if (value) |
|
*shadow |= BIT(offset); |
|
else |
|
*shadow &= ~BIT(offset); |
|
|
|
iowrite16be(*shadow, port); |
|
spin_unlock(&mod->lock); |
|
} |
|
|
|
static void ttl_write_reg(struct ttl_module *mod, u8 reg, u16 val) |
|
{ |
|
iowrite16be(reg, &mod->regs->control); |
|
iowrite16be(val, &mod->regs->control); |
|
} |
|
|
|
static void ttl_setup_device(struct ttl_module *mod) |
|
{ |
|
/* reset the device to a known state */ |
|
iowrite16be(0x0000, &mod->regs->control); |
|
iowrite16be(0x0001, &mod->regs->control); |
|
iowrite16be(0x0000, &mod->regs->control); |
|
|
|
/* put all ports in open-drain mode */ |
|
ttl_write_reg(mod, PORTA_IOCTL, 0x00ff); |
|
ttl_write_reg(mod, PORTB_IOCTL, 0x00ff); |
|
ttl_write_reg(mod, PORTC_IOCTL, 0x000f); |
|
|
|
/* set all ports as outputs */ |
|
ttl_write_reg(mod, PORTA_DIRECTION, 0x0000); |
|
ttl_write_reg(mod, PORTB_DIRECTION, 0x0000); |
|
ttl_write_reg(mod, PORTC_DIRECTION, 0x0000); |
|
|
|
/* set all ports to drive zeroes */ |
|
iowrite16be(0x0000, &mod->regs->porta); |
|
iowrite16be(0x0000, &mod->regs->portb); |
|
iowrite16be(0x0000, &mod->regs->portc); |
|
|
|
/* enable all ports */ |
|
ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE | CONF_PBE | CONF_PCE); |
|
} |
|
|
|
static int ttl_probe(struct platform_device *pdev) |
|
{ |
|
struct janz_platform_data *pdata; |
|
struct ttl_module *mod; |
|
struct gpio_chip *gpio; |
|
int ret; |
|
|
|
pdata = dev_get_platdata(&pdev->dev); |
|
if (!pdata) { |
|
dev_err(&pdev->dev, "no platform data\n"); |
|
return -ENXIO; |
|
} |
|
|
|
mod = devm_kzalloc(&pdev->dev, sizeof(*mod), GFP_KERNEL); |
|
if (!mod) |
|
return -ENOMEM; |
|
|
|
platform_set_drvdata(pdev, mod); |
|
spin_lock_init(&mod->lock); |
|
|
|
/* get access to the MODULbus registers for this module */ |
|
mod->regs = devm_platform_ioremap_resource(pdev, 0); |
|
if (IS_ERR(mod->regs)) |
|
return PTR_ERR(mod->regs); |
|
|
|
ttl_setup_device(mod); |
|
|
|
/* Initialize the GPIO data structures */ |
|
gpio = &mod->gpio; |
|
gpio->parent = &pdev->dev; |
|
gpio->label = pdev->name; |
|
gpio->get = ttl_get_value; |
|
gpio->set = ttl_set_value; |
|
gpio->owner = THIS_MODULE; |
|
|
|
/* request dynamic allocation */ |
|
gpio->base = -1; |
|
gpio->ngpio = 20; |
|
|
|
ret = devm_gpiochip_add_data(&pdev->dev, gpio, NULL); |
|
if (ret) { |
|
dev_err(&pdev->dev, "unable to add GPIO chip\n"); |
|
return ret; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static struct platform_driver ttl_driver = { |
|
.driver = { |
|
.name = DRV_NAME, |
|
}, |
|
.probe = ttl_probe, |
|
}; |
|
|
|
module_platform_driver(ttl_driver); |
|
|
|
MODULE_AUTHOR("Ira W. Snyder <[email protected]>"); |
|
MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver"); |
|
MODULE_LICENSE("GPL"); |
|
MODULE_ALIAS("platform:janz-ttl");
|
|
|