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gpio: aspeed: Add SGPIO driver

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Add SGPIO driver support for Aspeed AST2500 SoC.

Signed-off-by: Hongwei Zhang <hongweiz@ami.com>
Reviewed-by:   Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/1566335128-31498-2-git-send-email-hongweiz@ami.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Hongwei Zhang 2019-08-20 17:05:28 -04:00 committed by Linus Walleij
parent d5d4aa1ec1
commit 7db47faae7
1 changed files with 533 additions and 0 deletions
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drivers/gpio/sgpio-aspeed.c Normal file
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2019 American Megatrends International LLC.
*
* Author: Karthikeyan Mani <karthikeyanm@amiindia.co.in>
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/gpio/driver.h>
#include <linux/hashtable.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#define MAX_NR_SGPIO 80
#define ASPEED_SGPIO_CTRL 0x54
#define ASPEED_SGPIO_PINS_MASK GENMASK(9, 6)
#define ASPEED_SGPIO_CLK_DIV_MASK GENMASK(31, 16)
#define ASPEED_SGPIO_ENABLE BIT(0)
struct aspeed_sgpio {
struct gpio_chip chip;
struct clk *pclk;
spinlock_t lock;
void __iomem *base;
uint32_t dir_in[3];
int irq;
};
struct aspeed_sgpio_bank {
uint16_t val_regs;
uint16_t rdata_reg;
uint16_t irq_regs;
const char names[4][3];
};
/*
* Note: The "value" register returns the input value when the GPIO is
* configured as an input.
*
* The "rdata" register returns the output value when the GPIO is
* configured as an output.
*/
static const struct aspeed_sgpio_bank aspeed_sgpio_banks[] = {
{
.val_regs = 0x0000,
.rdata_reg = 0x0070,
.irq_regs = 0x0004,
.names = { "A", "B", "C", "D" },
},
{
.val_regs = 0x001C,
.rdata_reg = 0x0074,
.irq_regs = 0x0020,
.names = { "E", "F", "G", "H" },
},
{
.val_regs = 0x0038,
.rdata_reg = 0x0078,
.irq_regs = 0x003C,
.names = { "I", "J" },
},
};
enum aspeed_sgpio_reg {
reg_val,
reg_rdata,
reg_irq_enable,
reg_irq_type0,
reg_irq_type1,
reg_irq_type2,
reg_irq_status,
};
#define GPIO_VAL_VALUE 0x00
#define GPIO_IRQ_ENABLE 0x00
#define GPIO_IRQ_TYPE0 0x04
#define GPIO_IRQ_TYPE1 0x08
#define GPIO_IRQ_TYPE2 0x0C
#define GPIO_IRQ_STATUS 0x10
static void __iomem *bank_reg(struct aspeed_sgpio *gpio,
const struct aspeed_sgpio_bank *bank,
const enum aspeed_sgpio_reg reg)
{
switch (reg) {
case reg_val:
return gpio->base + bank->val_regs + GPIO_VAL_VALUE;
case reg_rdata:
return gpio->base + bank->rdata_reg;
case reg_irq_enable:
return gpio->base + bank->irq_regs + GPIO_IRQ_ENABLE;
case reg_irq_type0:
return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE0;
case reg_irq_type1:
return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE1;
case reg_irq_type2:
return gpio->base + bank->irq_regs + GPIO_IRQ_TYPE2;
case reg_irq_status:
return gpio->base + bank->irq_regs + GPIO_IRQ_STATUS;
default:
/* acturally if code runs to here, it's an error case */
BUG_ON(1);
}
}
#define GPIO_BANK(x) ((x) >> 5)
#define GPIO_OFFSET(x) ((x) & 0x1f)
#define GPIO_BIT(x) BIT(GPIO_OFFSET(x))
static const struct aspeed_sgpio_bank *to_bank(unsigned int offset)
{
unsigned int bank = GPIO_BANK(offset);
WARN_ON(bank >= ARRAY_SIZE(aspeed_sgpio_banks));
return &aspeed_sgpio_banks[bank];
}
static int aspeed_sgpio_get(struct gpio_chip *gc, unsigned int offset)
{
struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
const struct aspeed_sgpio_bank *bank = to_bank(offset);
unsigned long flags;
enum aspeed_sgpio_reg reg;
bool is_input;
int rc = 0;
spin_lock_irqsave(&gpio->lock, flags);
is_input = gpio->dir_in[GPIO_BANK(offset)] & GPIO_BIT(offset);
reg = is_input ? reg_val : reg_rdata;
rc = !!(ioread32(bank_reg(gpio, bank, reg)) & GPIO_BIT(offset));
spin_unlock_irqrestore(&gpio->lock, flags);
return rc;
}
static void sgpio_set_value(struct gpio_chip *gc, unsigned int offset, int val)
{
struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
const struct aspeed_sgpio_bank *bank = to_bank(offset);
void __iomem *addr;
u32 reg = 0;
addr = bank_reg(gpio, bank, reg_val);
reg = ioread32(addr);
if (val)
reg |= GPIO_BIT(offset);
else
reg &= ~GPIO_BIT(offset);
iowrite32(reg, addr);
}
static void aspeed_sgpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&gpio->lock, flags);
sgpio_set_value(gc, offset, val);
spin_unlock_irqrestore(&gpio->lock, flags);
}
static int aspeed_sgpio_dir_in(struct gpio_chip *gc, unsigned int offset)
{
struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&gpio->lock, flags);
gpio->dir_in[GPIO_BANK(offset)] |= GPIO_BIT(offset);
spin_unlock_irqrestore(&gpio->lock, flags);
return 0;
}
static int aspeed_sgpio_dir_out(struct gpio_chip *gc, unsigned int offset, int val)
{
struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&gpio->lock, flags);
gpio->dir_in[GPIO_BANK(offset)] &= ~GPIO_BIT(offset);
sgpio_set_value(gc, offset, val);
spin_unlock_irqrestore(&gpio->lock, flags);
return 0;
}
static int aspeed_sgpio_get_direction(struct gpio_chip *gc, unsigned int offset)
{
int dir_status;
struct aspeed_sgpio *gpio = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&gpio->lock, flags);
dir_status = gpio->dir_in[GPIO_BANK(offset)] & GPIO_BIT(offset);
spin_unlock_irqrestore(&gpio->lock, flags);
return dir_status;
}
static void irqd_to_aspeed_sgpio_data(struct irq_data *d,
struct aspeed_sgpio **gpio,
const struct aspeed_sgpio_bank **bank,
u32 *bit, int *offset)
{
struct aspeed_sgpio *internal;
*offset = irqd_to_hwirq(d);
internal = irq_data_get_irq_chip_data(d);
WARN_ON(!internal);
*gpio = internal;
*bank = to_bank(*offset);
*bit = GPIO_BIT(*offset);
}
static void aspeed_sgpio_irq_ack(struct irq_data *d)
{
const struct aspeed_sgpio_bank *bank;
struct aspeed_sgpio *gpio;
unsigned long flags;
void __iomem *status_addr;
int offset;
u32 bit;
irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
status_addr = bank_reg(gpio, bank, reg_irq_status);
spin_lock_irqsave(&gpio->lock, flags);
iowrite32(bit, status_addr);
spin_unlock_irqrestore(&gpio->lock, flags);
}
static void aspeed_sgpio_irq_set_mask(struct irq_data *d, bool set)
{
const struct aspeed_sgpio_bank *bank;
struct aspeed_sgpio *gpio;
unsigned long flags;
u32 reg, bit;
void __iomem *addr;
int offset;
irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
addr = bank_reg(gpio, bank, reg_irq_enable);
spin_lock_irqsave(&gpio->lock, flags);
reg = ioread32(addr);
if (set)
reg |= bit;
else
reg &= ~bit;
iowrite32(reg, addr);
spin_unlock_irqrestore(&gpio->lock, flags);
}
static void aspeed_sgpio_irq_mask(struct irq_data *d)
{
aspeed_sgpio_irq_set_mask(d, false);
}
static void aspeed_sgpio_irq_unmask(struct irq_data *d)
{
aspeed_sgpio_irq_set_mask(d, true);
}
static int aspeed_sgpio_set_type(struct irq_data *d, unsigned int type)
{
u32 type0 = 0;
u32 type1 = 0;
u32 type2 = 0;
u32 bit, reg;
const struct aspeed_sgpio_bank *bank;
irq_flow_handler_t handler;
struct aspeed_sgpio *gpio;
unsigned long flags;
void __iomem *addr;
int offset;
irqd_to_aspeed_sgpio_data(d, &gpio, &bank, &bit, &offset);
switch (type & IRQ_TYPE_SENSE_MASK) {
case IRQ_TYPE_EDGE_BOTH:
type2 |= bit;
/* fall through */
case IRQ_TYPE_EDGE_RISING:
type0 |= bit;
/* fall through */
case IRQ_TYPE_EDGE_FALLING:
handler = handle_edge_irq;
break;
case IRQ_TYPE_LEVEL_HIGH:
type0 |= bit;
/* fall through */
case IRQ_TYPE_LEVEL_LOW:
type1 |= bit;
handler = handle_level_irq;
break;
default:
return -EINVAL;
}
spin_lock_irqsave(&gpio->lock, flags);
addr = bank_reg(gpio, bank, reg_irq_type0);
reg = ioread32(addr);
reg = (reg & ~bit) | type0;
iowrite32(reg, addr);
addr = bank_reg(gpio, bank, reg_irq_type1);
reg = ioread32(addr);
reg = (reg & ~bit) | type1;
iowrite32(reg, addr);
addr = bank_reg(gpio, bank, reg_irq_type2);
reg = ioread32(addr);
reg = (reg & ~bit) | type2;
iowrite32(reg, addr);
spin_unlock_irqrestore(&gpio->lock, flags);
irq_set_handler_locked(d, handler);
return 0;
}
static void aspeed_sgpio_irq_handler(struct irq_desc *desc)
{
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct irq_chip *ic = irq_desc_get_chip(desc);
struct aspeed_sgpio *data = gpiochip_get_data(gc);
unsigned int i, p, girq;
unsigned long reg;
chained_irq_enter(ic, desc);
for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
const struct aspeed_sgpio_bank *bank = &aspeed_sgpio_banks[i];
reg = ioread32(bank_reg(data, bank, reg_irq_status));
for_each_set_bit(p, &reg, 32) {
girq = irq_find_mapping(gc->irq.domain, i * 32 + p);
generic_handle_irq(girq);
}
}
chained_irq_exit(ic, desc);
}
static struct irq_chip aspeed_sgpio_irqchip = {
.name = "aspeed-sgpio",
.irq_ack = aspeed_sgpio_irq_ack,
.irq_mask = aspeed_sgpio_irq_mask,
.irq_unmask = aspeed_sgpio_irq_unmask,
.irq_set_type = aspeed_sgpio_set_type,
};
static int aspeed_sgpio_setup_irqs(struct aspeed_sgpio *gpio,
struct platform_device *pdev)
{
int rc, i;
const struct aspeed_sgpio_bank *bank;
struct gpio_irq_chip *irq;
rc = platform_get_irq(pdev, 0);
if (rc < 0)
return rc;
gpio->irq = rc;
/* Disable IRQ and clear Interrupt status registers for all SPGIO Pins. */
for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
bank = &aspeed_sgpio_banks[i];
/* disable irq enable bits */
iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_enable));
/* clear status bits */
iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_status));
}
irq = &gpio->chip.irq;
irq->chip = &aspeed_sgpio_irqchip;
irq->handler = handle_bad_irq;
irq->default_type = IRQ_TYPE_NONE;
irq->parent_handler = aspeed_sgpio_irq_handler;
irq->parent_handler_data = gpio;
irq->parents = &gpio->irq;
irq->num_parents = 1;
/* set IRQ settings and Enable Interrupt */
for (i = 0; i < ARRAY_SIZE(aspeed_sgpio_banks); i++) {
bank = &aspeed_sgpio_banks[i];
/* set falling or level-low irq */
iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type0));
/* trigger type is edge */
iowrite32(0x00000000, bank_reg(gpio, bank, reg_irq_type1));
/* dual edge trigger mode. */
iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_type2));
/* enable irq */
iowrite32(0xffffffff, bank_reg(gpio, bank, reg_irq_enable));
}
return 0;
}
static const struct of_device_id aspeed_sgpio_of_table[] = {
{ .compatible = "aspeed,ast2400-sgpio" },
{ .compatible = "aspeed,ast2500-sgpio" },
{}
};
MODULE_DEVICE_TABLE(of, aspeed_sgpio_of_table);
static int __init aspeed_sgpio_probe(struct platform_device *pdev)
{
struct aspeed_sgpio *gpio;
u32 nr_gpios, sgpio_freq, sgpio_clk_div;
int rc;
unsigned long apb_freq;
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio)
return -ENOMEM;
gpio->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(gpio->base))
return PTR_ERR(gpio->base);
rc = of_property_read_u32(pdev->dev.of_node, "ngpios", &nr_gpios);
if (rc < 0) {
dev_err(&pdev->dev, "Could not read ngpios property\n");
return -EINVAL;
} else if (nr_gpios > MAX_NR_SGPIO) {
dev_err(&pdev->dev, "Number of GPIOs exceeds the maximum of %d: %d\n",
MAX_NR_SGPIO, nr_gpios);
return -EINVAL;
}
rc = of_property_read_u32(pdev->dev.of_node, "bus-frequency", &sgpio_freq);
if (rc < 0) {
dev_err(&pdev->dev, "Could not read bus-frequency property\n");
return -EINVAL;
}
gpio->pclk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(gpio->pclk)) {
dev_err(&pdev->dev, "devm_clk_get failed\n");
return PTR_ERR(gpio->pclk);
}
apb_freq = clk_get_rate(gpio->pclk);
/*
* From the datasheet,
* SGPIO period = 1/PCLK * 2 * (GPIO254[31:16] + 1)
* period = 2 * (GPIO254[31:16] + 1) / PCLK
* frequency = 1 / (2 * (GPIO254[31:16] + 1) / PCLK)
* frequency = PCLK / (2 * (GPIO254[31:16] + 1))
* frequency * 2 * (GPIO254[31:16] + 1) = PCLK
* GPIO254[31:16] = PCLK / (frequency * 2) - 1
*/
if (sgpio_freq == 0)
return -EINVAL;
sgpio_clk_div = (apb_freq / (sgpio_freq * 2)) - 1;
if (sgpio_clk_div > (1 << 16) - 1)
return -EINVAL;
iowrite32(FIELD_PREP(ASPEED_SGPIO_CLK_DIV_MASK, sgpio_clk_div) |
FIELD_PREP(ASPEED_SGPIO_PINS_MASK, (nr_gpios / 8)) |
ASPEED_SGPIO_ENABLE,
gpio->base + ASPEED_SGPIO_CTRL);
spin_lock_init(&gpio->lock);
gpio->chip.parent = &pdev->dev;
gpio->chip.ngpio = nr_gpios;
gpio->chip.direction_input = aspeed_sgpio_dir_in;
gpio->chip.direction_output = aspeed_sgpio_dir_out;
gpio->chip.get_direction = aspeed_sgpio_get_direction;
gpio->chip.request = NULL;
gpio->chip.free = NULL;
gpio->chip.get = aspeed_sgpio_get;
gpio->chip.set = aspeed_sgpio_set;
gpio->chip.set_config = NULL;
gpio->chip.label = dev_name(&pdev->dev);
gpio->chip.base = -1;
/* set all SGPIO pins as input (1). */
memset(gpio->dir_in, 0xff, sizeof(gpio->dir_in));
aspeed_sgpio_setup_irqs(gpio, pdev);
rc = devm_gpiochip_add_data(&pdev->dev, &gpio->chip, gpio);
if (rc < 0)
return rc;
return 0;
}
static struct platform_driver aspeed_sgpio_driver = {
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = aspeed_sgpio_of_table,
},
};
module_platform_driver_probe(aspeed_sgpio_driver, aspeed_sgpio_probe);
MODULE_DESCRIPTION("Aspeed Serial GPIO Driver");
MODULE_LICENSE("GPL");