gpio-thunderx.c
/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2016, 2017 Cavium Inc.
*/
#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/spinlock.h>
#define GPIO_RX_DAT 0x0
#define GPIO_TX_SET 0x8
#define GPIO_TX_CLR 0x10
#define GPIO_CONST 0x90
#define GPIO_CONST_GPIOS_MASK 0xff
#define GPIO_BIT_CFG 0x400
#define GPIO_BIT_CFG_TX_OE BIT(0)
#define GPIO_BIT_CFG_PIN_XOR BIT(1)
#define GPIO_BIT_CFG_INT_EN BIT(2)
#define GPIO_BIT_CFG_INT_TYPE BIT(3)
#define GPIO_BIT_CFG_FIL_MASK GENMASK(11, 4)
#define GPIO_BIT_CFG_FIL_CNT_SHIFT 4
#define GPIO_BIT_CFG_FIL_SEL_SHIFT 8
#define GPIO_BIT_CFG_TX_OD BIT(12)
#define GPIO_BIT_CFG_PIN_SEL_MASK GENMASK(25, 16)
#define GPIO_INTR 0x800
#define GPIO_INTR_INTR BIT(0)
#define GPIO_INTR_INTR_W1S BIT(1)
#define GPIO_INTR_ENA_W1C BIT(2)
#define GPIO_INTR_ENA_W1S BIT(3)
#define GPIO_2ND_BANK 0x1400
#define GLITCH_FILTER_400NS ((4u << GPIO_BIT_CFG_FIL_SEL_SHIFT) | \
(9u << GPIO_BIT_CFG_FIL_CNT_SHIFT))
struct thunderx_gpio;
struct thunderx_line {
struct thunderx_gpio *txgpio;
unsigned int line;
unsigned int fil_bits;
};
struct thunderx_gpio {
struct gpio_chip chip;
u8 __iomem *register_base;
struct irq_domain *irqd;
struct msix_entry *msix_entries; /* per line MSI-X */
struct thunderx_line *line_entries; /* per line irq info */
raw_spinlock_t lock;
unsigned long invert_mask[2];
unsigned long od_mask[2];
int base_msi;
};
static unsigned int bit_cfg_reg(unsigned int line)
{
return 8 * line + GPIO_BIT_CFG;
}
static unsigned int intr_reg(unsigned int line)
{
return 8 * line + GPIO_INTR;
}
static bool thunderx_gpio_is_gpio_nowarn(struct thunderx_gpio *txgpio,
unsigned int line)
{
u64 bit_cfg = readq(txgpio->register_base + bit_cfg_reg(line));
return (bit_cfg & GPIO_BIT_CFG_PIN_SEL_MASK) == 0;
}
/*
* Check (and WARN) that the pin is available for GPIO. We will not
* allow modification of the state of non-GPIO pins from this driver.
*/
static bool thunderx_gpio_is_gpio(struct thunderx_gpio *txgpio,
unsigned int line)
{
bool rv = thunderx_gpio_is_gpio_nowarn(txgpio, line);
WARN_RATELIMIT(!rv, "Pin %d not available for GPIO\n", line);
return rv;
}
static int thunderx_gpio_request(struct gpio_chip *chip, unsigned int line)
{
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
return thunderx_gpio_is_gpio(txgpio, line) ? 0 : -EIO;
}
static int thunderx_gpio_dir_in(struct gpio_chip *chip, unsigned int line)
{
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
if (!thunderx_gpio_is_gpio(txgpio, line))
return -EIO;
raw_spin_lock(&txgpio->lock);
clear_bit(line, txgpio->invert_mask);
clear_bit(line, txgpio->od_mask);
writeq(txgpio->line_entries[line].fil_bits,
txgpio->register_base + bit_cfg_reg(line));
raw_spin_unlock(&txgpio->lock);
return 0;
}
static void thunderx_gpio_set(struct gpio_chip *chip, unsigned int line,
int value)
{
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
int bank = line / 64;
int bank_bit = line % 64;
void __iomem *reg = txgpio->register_base +
(bank * GPIO_2ND_BANK) + (value ? GPIO_TX_SET : GPIO_TX_CLR);
writeq(BIT_ULL(bank_bit), reg);
}
static int thunderx_gpio_dir_out(struct gpio_chip *chip, unsigned int line,
int value)
{
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
u64 bit_cfg = txgpio->line_entries[line].fil_bits | GPIO_BIT_CFG_TX_OE;
if (!thunderx_gpio_is_gpio(txgpio, line))
return -EIO;
raw_spin_lock(&txgpio->lock);
thunderx_gpio_set(chip, line, value);
if (test_bit(line, txgpio->invert_mask))
bit_cfg |= GPIO_BIT_CFG_PIN_XOR;
if (test_bit(line, txgpio->od_mask))
bit_cfg |= GPIO_BIT_CFG_TX_OD;
writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(line));
raw_spin_unlock(&txgpio->lock);
return 0;
}
static int thunderx_gpio_get_direction(struct gpio_chip *chip, unsigned int line)
{
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
u64 bit_cfg;
if (!thunderx_gpio_is_gpio_nowarn(txgpio, line))
/*
* Say it is input for now to avoid WARNing on
* gpiochip_add_data(). We will WARN if someone
* requests it or tries to use it.
*/
return 1;
bit_cfg = readq(txgpio->register_base + bit_cfg_reg(line));
return !(bit_cfg & GPIO_BIT_CFG_TX_OE);
}
static int thunderx_gpio_set_config(struct gpio_chip *chip,
unsigned int line,
unsigned long cfg)
{
bool orig_invert, orig_od, orig_dat, new_invert, new_od;
u32 arg, sel;
u64 bit_cfg;
int bank = line / 64;
int bank_bit = line % 64;
int ret = -ENOTSUPP;
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
void __iomem *reg = txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_SET;
if (!thunderx_gpio_is_gpio(txgpio, line))
return -EIO;
raw_spin_lock(&txgpio->lock);
orig_invert = test_bit(line, txgpio->invert_mask);
new_invert = orig_invert;
orig_od = test_bit(line, txgpio->od_mask);
new_od = orig_od;
orig_dat = ((readq(reg) >> bank_bit) & 1) ^ orig_invert;
bit_cfg = readq(txgpio->register_base + bit_cfg_reg(line));
switch (pinconf_to_config_param(cfg)) {
case PIN_CONFIG_DRIVE_OPEN_DRAIN:
/*
* Weird, setting open-drain mode causes signal
* inversion. Note this so we can compensate in the
* dir_out function.
*/
set_bit(line, txgpio->invert_mask);
new_invert = true;
set_bit(line, txgpio->od_mask);
new_od = true;
ret = 0;
break;
case PIN_CONFIG_DRIVE_PUSH_PULL:
clear_bit(line, txgpio->invert_mask);
new_invert = false;
clear_bit(line, txgpio->od_mask);
new_od = false;
ret = 0;
break;
case PIN_CONFIG_INPUT_DEBOUNCE:
arg = pinconf_to_config_argument(cfg);
if (arg > 1228) { /* 15 * 2^15 * 2.5nS maximum */
ret = -EINVAL;
break;
}
arg *= 400; /* scale to 2.5nS clocks. */
sel = 0;
while (arg > 15) {
sel++;
arg++; /* always round up */
arg >>= 1;
}
txgpio->line_entries[line].fil_bits =
(sel << GPIO_BIT_CFG_FIL_SEL_SHIFT) |
(arg << GPIO_BIT_CFG_FIL_CNT_SHIFT);
bit_cfg &= ~GPIO_BIT_CFG_FIL_MASK;
bit_cfg |= txgpio->line_entries[line].fil_bits;
writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(line));
ret = 0;
break;
default:
break;
}
raw_spin_unlock(&txgpio->lock);
/*
* If currently output and OPEN_DRAIN changed, install the new
* settings
*/
if ((new_invert != orig_invert || new_od != orig_od) &&
(bit_cfg & GPIO_BIT_CFG_TX_OE))
ret = thunderx_gpio_dir_out(chip, line, orig_dat ^ new_invert);
return ret;
}
static int thunderx_gpio_get(struct gpio_chip *chip, unsigned int line)
{
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
int bank = line / 64;
int bank_bit = line % 64;
u64 read_bits = readq(txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_RX_DAT);
u64 masked_bits = read_bits & BIT_ULL(bank_bit);
if (test_bit(line, txgpio->invert_mask))
return masked_bits == 0;
else
return masked_bits != 0;
}
static void thunderx_gpio_set_multiple(struct gpio_chip *chip,
unsigned long *mask,
unsigned long *bits)
{
int bank;
u64 set_bits, clear_bits;
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
for (bank = 0; bank <= chip->ngpio / 64; bank++) {
set_bits = bits[bank] & mask[bank];
clear_bits = ~bits[bank] & mask[bank];
writeq(set_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_SET);
writeq(clear_bits, txgpio->register_base + (bank * GPIO_2ND_BANK) + GPIO_TX_CLR);
}
}
static void thunderx_gpio_irq_ack(struct irq_data *data)
{
struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
writeq(GPIO_INTR_INTR,
txline->txgpio->register_base + intr_reg(txline->line));
}
static void thunderx_gpio_irq_mask(struct irq_data *data)
{
struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
writeq(GPIO_INTR_ENA_W1C,
txline->txgpio->register_base + intr_reg(txline->line));
}
static void thunderx_gpio_irq_mask_ack(struct irq_data *data)
{
struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
writeq(GPIO_INTR_ENA_W1C | GPIO_INTR_INTR,
txline->txgpio->register_base + intr_reg(txline->line));
}
static void thunderx_gpio_irq_unmask(struct irq_data *data)
{
struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
writeq(GPIO_INTR_ENA_W1S,
txline->txgpio->register_base + intr_reg(txline->line));
}
static int thunderx_gpio_irq_set_type(struct irq_data *data,
unsigned int flow_type)
{
struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
struct thunderx_gpio *txgpio = txline->txgpio;
u64 bit_cfg;
irqd_set_trigger_type(data, flow_type);
bit_cfg = txline->fil_bits | GPIO_BIT_CFG_INT_EN;
if (flow_type & IRQ_TYPE_EDGE_BOTH) {
irq_set_handler_locked(data, handle_fasteoi_ack_irq);
bit_cfg |= GPIO_BIT_CFG_INT_TYPE;
} else {
irq_set_handler_locked(data, handle_fasteoi_mask_irq);
}
raw_spin_lock(&txgpio->lock);
if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_LEVEL_LOW)) {
bit_cfg |= GPIO_BIT_CFG_PIN_XOR;
set_bit(txline->line, txgpio->invert_mask);
} else {
clear_bit(txline->line, txgpio->invert_mask);
}
clear_bit(txline->line, txgpio->od_mask);
writeq(bit_cfg, txgpio->register_base + bit_cfg_reg(txline->line));
raw_spin_unlock(&txgpio->lock);
return IRQ_SET_MASK_OK;
}
static void thunderx_gpio_irq_enable(struct irq_data *data)
{
irq_chip_enable_parent(data);
thunderx_gpio_irq_unmask(data);
}
static void thunderx_gpio_irq_disable(struct irq_data *data)
{
thunderx_gpio_irq_mask(data);
irq_chip_disable_parent(data);
}
static int thunderx_gpio_irq_request_resources(struct irq_data *data)
{
struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
struct thunderx_gpio *txgpio = txline->txgpio;
struct irq_data *parent_data = data->parent_data;
int r;
r = gpiochip_lock_as_irq(&txgpio->chip, txline->line);
if (r)
return r;
if (parent_data && parent_data->chip->irq_request_resources) {
r = parent_data->chip->irq_request_resources(parent_data);
if (r)
goto error;
}
return 0;
error:
gpiochip_unlock_as_irq(&txgpio->chip, txline->line);
return r;
}
static void thunderx_gpio_irq_release_resources(struct irq_data *data)
{
struct thunderx_line *txline = irq_data_get_irq_chip_data(data);
struct thunderx_gpio *txgpio = txline->txgpio;
struct irq_data *parent_data = data->parent_data;
if (parent_data && parent_data->chip->irq_release_resources)
parent_data->chip->irq_release_resources(parent_data);
gpiochip_unlock_as_irq(&txgpio->chip, txline->line);
}
/*
* Interrupts are chained from underlying MSI-X vectors. We have
* these irq_chip functions to be able to handle level triggering
* semantics and other acknowledgment tasks associated with the GPIO
* mechanism.
*/
static struct irq_chip thunderx_gpio_irq_chip = {
.name = "GPIO",
.irq_enable = thunderx_gpio_irq_enable,
.irq_disable = thunderx_gpio_irq_disable,
.irq_ack = thunderx_gpio_irq_ack,
.irq_mask = thunderx_gpio_irq_mask,
.irq_mask_ack = thunderx_gpio_irq_mask_ack,
.irq_unmask = thunderx_gpio_irq_unmask,
.irq_eoi = irq_chip_eoi_parent,
.irq_set_affinity = irq_chip_set_affinity_parent,
.irq_request_resources = thunderx_gpio_irq_request_resources,
.irq_release_resources = thunderx_gpio_irq_release_resources,
.irq_set_type = thunderx_gpio_irq_set_type,
.flags = IRQCHIP_SET_TYPE_MASKED
};
static int thunderx_gpio_irq_translate(struct irq_domain *d,
struct irq_fwspec *fwspec,
irq_hw_number_t *hwirq,
unsigned int *type)
{
struct thunderx_gpio *txgpio = d->host_data;
if (WARN_ON(fwspec->param_count < 2))
return -EINVAL;
if (fwspec->param[0] >= txgpio->chip.ngpio)
return -EINVAL;
*hwirq = fwspec->param[0];
*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
return 0;
}
static int thunderx_gpio_irq_alloc(struct irq_domain *d, unsigned int virq,
unsigned int nr_irqs, void *arg)
{
struct thunderx_line *txline = arg;
return irq_domain_set_hwirq_and_chip(d, virq, txline->line,
&thunderx_gpio_irq_chip, txline);
}
static const struct irq_domain_ops thunderx_gpio_irqd_ops = {
.alloc = thunderx_gpio_irq_alloc,
.translate = thunderx_gpio_irq_translate
};
static int thunderx_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
{
struct thunderx_gpio *txgpio = gpiochip_get_data(chip);
return irq_find_mapping(txgpio->irqd, offset);
}
static int thunderx_gpio_probe(struct pci_dev *pdev,
const struct pci_device_id *id)
{
void __iomem * const *tbl;
struct device *dev = &pdev->dev;
struct thunderx_gpio *txgpio;
struct gpio_chip *chip;
int ngpio, i;
int err = 0;
txgpio = devm_kzalloc(dev, sizeof(*txgpio), GFP_KERNEL);
if (!txgpio)
return -ENOMEM;
raw_spin_lock_init(&txgpio->lock);
chip = &txgpio->chip;
pci_set_drvdata(pdev, txgpio);
err = pcim_enable_device(pdev);
if (err) {
dev_err(dev, "Failed to enable PCI device: err %d\n", err);
goto out;
}
err = pcim_iomap_regions(pdev, 1 << 0, KBUILD_MODNAME);
if (err) {
dev_err(dev, "Failed to iomap PCI device: err %d\n", err);
goto out;
}
tbl = pcim_iomap_table(pdev);
txgpio->register_base = tbl[0];
if (!txgpio->register_base) {
dev_err(dev, "Cannot map PCI resource\n");
err = -ENOMEM;
goto out;
}
if (pdev->subsystem_device == 0xa10a) {
/* CN88XX has no GPIO_CONST register*/
ngpio = 50;
txgpio->base_msi = 48;
} else {
u64 c = readq(txgpio->register_base + GPIO_CONST);
ngpio = c & GPIO_CONST_GPIOS_MASK;
txgpio->base_msi = (c >> 8) & 0xff;
}
txgpio->msix_entries = devm_kcalloc(dev,
ngpio, sizeof(struct msix_entry),
GFP_KERNEL);
if (!txgpio->msix_entries) {
err = -ENOMEM;
goto out;
}
txgpio->line_entries = devm_kcalloc(dev,
ngpio,
sizeof(struct thunderx_line),
GFP_KERNEL);
if (!txgpio->line_entries) {
err = -ENOMEM;
goto out;
}
for (i = 0; i < ngpio; i++) {
u64 bit_cfg = readq(txgpio->register_base + bit_cfg_reg(i));
txgpio->msix_entries[i].entry = txgpio->base_msi + (2 * i);
txgpio->line_entries[i].line = i;
txgpio->line_entries[i].txgpio = txgpio;
/*
* If something has already programmed the pin, use
* the existing glitch filter settings, otherwise go
* to 400nS.
*/
txgpio->line_entries[i].fil_bits = bit_cfg ?
(bit_cfg & GPIO_BIT_CFG_FIL_MASK) : GLITCH_FILTER_400NS;
if ((bit_cfg & GPIO_BIT_CFG_TX_OE) && (bit_cfg & GPIO_BIT_CFG_TX_OD))
set_bit(i, txgpio->od_mask);
if (bit_cfg & GPIO_BIT_CFG_PIN_XOR)
set_bit(i, txgpio->invert_mask);
}
/* Enable all MSI-X for interrupts on all possible lines. */
err = pci_enable_msix_range(pdev, txgpio->msix_entries, ngpio, ngpio);
if (err < 0)
goto out;
/*
* Push GPIO specific irqdomain on hierarchy created as a side
* effect of the pci_enable_msix()
*/
txgpio->irqd = irq_domain_create_hierarchy(irq_get_irq_data(txgpio->msix_entries[0].vector)->domain,
0, 0, of_node_to_fwnode(dev->of_node),
&thunderx_gpio_irqd_ops, txgpio);
if (!txgpio->irqd) {
err = -ENOMEM;
goto out;
}
/* Push on irq_data and the domain for each line. */
for (i = 0; i < ngpio; i++) {
err = irq_domain_push_irq(txgpio->irqd,
txgpio->msix_entries[i].vector,
&txgpio->line_entries[i]);
if (err < 0)
dev_err(dev, "irq_domain_push_irq: %d\n", err);
}
chip->label = KBUILD_MODNAME;
chip->parent = dev;
chip->owner = THIS_MODULE;
chip->request = thunderx_gpio_request;
chip->base = -1; /* System allocated */
chip->can_sleep = false;
chip->ngpio = ngpio;
chip->get_direction = thunderx_gpio_get_direction;
chip->direction_input = thunderx_gpio_dir_in;
chip->get = thunderx_gpio_get;
chip->direction_output = thunderx_gpio_dir_out;
chip->set = thunderx_gpio_set;
chip->set_multiple = thunderx_gpio_set_multiple;
chip->set_config = thunderx_gpio_set_config;
chip->to_irq = thunderx_gpio_to_irq;
err = devm_gpiochip_add_data(dev, chip, txgpio);
if (err)
goto out;
dev_info(dev, "ThunderX GPIO: %d lines with base %d.\n",
ngpio, chip->base);
return 0;
out:
pci_set_drvdata(pdev, NULL);
return err;
}
static void thunderx_gpio_remove(struct pci_dev *pdev)
{
int i;
struct thunderx_gpio *txgpio = pci_get_drvdata(pdev);
for (i = 0; i < txgpio->chip.ngpio; i++)
irq_domain_pop_irq(txgpio->irqd,
txgpio->msix_entries[i].vector);
irq_domain_remove(txgpio->irqd);
pci_set_drvdata(pdev, NULL);
}
static const struct pci_device_id thunderx_gpio_id_table[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xA00A) },
{ 0, } /* end of table */
};
MODULE_DEVICE_TABLE(pci, thunderx_gpio_id_table);
static struct pci_driver thunderx_gpio_driver = {
.name = KBUILD_MODNAME,
.id_table = thunderx_gpio_id_table,
.probe = thunderx_gpio_probe,
.remove = thunderx_gpio_remove,
};
module_pci_driver(thunderx_gpio_driver);
MODULE_DESCRIPTION("Cavium Inc. ThunderX/OCTEON-TX GPIO Driver");
MODULE_LICENSE("GPL");