blob: 5830dc9b87f3bfabe6034afa88a1e6ab3f2975f0 [file] [log] [blame]
/*
* GPIO Greybus driver.
*
* Copyright 2014 Google Inc.
* Copyright 2014 Linaro Ltd.
*
* Released under the GPLv2 only.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/gpio.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/mutex.h>
#include "greybus.h"
struct gb_gpio_line {
/* The following has to be an array of line_max entries */
/* --> make them just a flags field */
u8 active: 1,
direction: 1, /* 0 = output, 1 = input */
value: 1; /* 0 = low, 1 = high */
u16 debounce_usec;
u8 irq_type;
bool irq_type_pending;
bool masked;
bool masked_pending;
};
struct gb_gpio_controller {
struct gb_connection *connection;
u8 line_max; /* max line number */
struct gb_gpio_line *lines;
struct gpio_chip chip;
struct irq_chip irqc;
struct irq_chip *irqchip;
struct irq_domain *irqdomain;
unsigned int irq_base;
irq_flow_handler_t irq_handler;
unsigned int irq_default_type;
struct mutex irq_lock;
};
#define gpio_chip_to_gb_gpio_controller(chip) \
container_of(chip, struct gb_gpio_controller, chip)
#define irq_data_to_gpio_chip(d) (d->domain->host_data)
static int gb_gpio_line_count_operation(struct gb_gpio_controller *ggc)
{
struct gb_gpio_line_count_response response;
int ret;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_LINE_COUNT,
NULL, 0, &response, sizeof(response));
if (!ret)
ggc->line_max = response.count;
return ret;
}
static int gb_gpio_activate_operation(struct gb_gpio_controller *ggc, u8 which)
{
struct gb_gpio_activate_request request;
int ret;
request.which = which;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_ACTIVATE,
&request, sizeof(request), NULL, 0);
if (!ret)
ggc->lines[which].active = true;
return ret;
}
static void gb_gpio_deactivate_operation(struct gb_gpio_controller *ggc,
u8 which)
{
struct gb_gpio_deactivate_request request;
int ret;
request.which = which;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DEACTIVATE,
&request, sizeof(request), NULL, 0);
if (ret) {
dev_err(ggc->chip.dev, "failed to deactivate gpio %u\n",
which);
return;
}
ggc->lines[which].active = false;
}
static int gb_gpio_get_direction_operation(struct gb_gpio_controller *ggc,
u8 which)
{
struct gb_gpio_get_direction_request request;
struct gb_gpio_get_direction_response response;
int ret;
u8 direction;
request.which = which;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_GET_DIRECTION,
&request, sizeof(request),
&response, sizeof(response));
if (ret)
return ret;
direction = response.direction;
if (direction && direction != 1) {
dev_warn(ggc->chip.dev,
"gpio %u direction was %u (should be 0 or 1)\n",
which, direction);
}
ggc->lines[which].direction = direction ? 1 : 0;
return 0;
}
static int gb_gpio_direction_in_operation(struct gb_gpio_controller *ggc,
u8 which)
{
struct gb_gpio_direction_in_request request;
int ret;
request.which = which;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DIRECTION_IN,
&request, sizeof(request), NULL, 0);
if (!ret)
ggc->lines[which].direction = 1;
return ret;
}
static int gb_gpio_direction_out_operation(struct gb_gpio_controller *ggc,
u8 which, bool value_high)
{
struct gb_gpio_direction_out_request request;
int ret;
request.which = which;
request.value = value_high ? 1 : 0;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_DIRECTION_OUT,
&request, sizeof(request), NULL, 0);
if (!ret)
ggc->lines[which].direction = 0;
return ret;
}
static int gb_gpio_get_value_operation(struct gb_gpio_controller *ggc,
u8 which)
{
struct gb_gpio_get_value_request request;
struct gb_gpio_get_value_response response;
int ret;
u8 value;
request.which = which;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_GET_VALUE,
&request, sizeof(request),
&response, sizeof(response));
if (ret) {
dev_err(ggc->chip.dev, "failed to get value of gpio %u\n",
which);
return ret;
}
value = response.value;
if (value && value != 1) {
dev_warn(ggc->chip.dev,
"gpio %u value was %u (should be 0 or 1)\n",
which, value);
}
ggc->lines[which].value = value ? 1 : 0;
return 0;
}
static void gb_gpio_set_value_operation(struct gb_gpio_controller *ggc,
u8 which, bool value_high)
{
struct gb_gpio_set_value_request request;
int ret;
if (ggc->lines[which].direction == 1) {
dev_warn(ggc->chip.dev,
"refusing to set value of input gpio %u\n", which);
return;
}
request.which = which;
request.value = value_high ? 1 : 0;
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_VALUE,
&request, sizeof(request), NULL, 0);
if (ret) {
dev_err(ggc->chip.dev, "failed to set value of gpio %u\n",
which);
return;
}
ggc->lines[which].value = request.value;
}
static int gb_gpio_set_debounce_operation(struct gb_gpio_controller *ggc,
u8 which, u16 debounce_usec)
{
struct gb_gpio_set_debounce_request request;
int ret;
request.which = which;
request.usec = cpu_to_le16(debounce_usec);
ret = gb_operation_sync(ggc->connection, GB_GPIO_TYPE_SET_DEBOUNCE,
&request, sizeof(request), NULL, 0);
if (!ret)
ggc->lines[which].debounce_usec = debounce_usec;
return ret;
}
static void _gb_gpio_irq_mask(struct gb_gpio_controller *ggc, u8 hwirq)
{
struct gb_gpio_irq_mask_request request;
int ret;
request.which = hwirq;
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_MASK,
&request, sizeof(request), NULL, 0);
if (ret)
dev_err(ggc->chip.dev, "failed to mask irq: %d\n", ret);
}
static void _gb_gpio_irq_unmask(struct gb_gpio_controller *ggc, u8 hwirq)
{
struct gb_gpio_irq_unmask_request request;
int ret;
request.which = hwirq;
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_UNMASK,
&request, sizeof(request), NULL, 0);
if (ret)
dev_err(ggc->chip.dev, "failed to unmask irq: %d\n", ret);
}
static void _gb_gpio_irq_set_type(struct gb_gpio_controller *ggc,
u8 hwirq, u8 type)
{
struct gb_gpio_irq_type_request request;
int ret;
request.which = hwirq;
request.type = type;
ret = gb_operation_sync(ggc->connection,
GB_GPIO_TYPE_IRQ_TYPE,
&request, sizeof(request), NULL, 0);
if (ret)
dev_err(ggc->chip.dev, "failed to set irq type: %d\n", ret);
}
static void gb_gpio_irq_mask(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
line->masked = true;
line->masked_pending = true;
}
static void gb_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
line->masked = false;
line->masked_pending = true;
}
static int gb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
u8 irq_type;
switch (type) {
case IRQ_TYPE_NONE:
irq_type = GB_GPIO_IRQ_TYPE_NONE;
break;
case IRQ_TYPE_EDGE_RISING:
irq_type = GB_GPIO_IRQ_TYPE_EDGE_RISING;
break;
case IRQ_TYPE_EDGE_FALLING:
irq_type = GB_GPIO_IRQ_TYPE_EDGE_FALLING;
break;
case IRQ_TYPE_EDGE_BOTH:
irq_type = GB_GPIO_IRQ_TYPE_EDGE_BOTH;
break;
case IRQ_TYPE_LEVEL_LOW:
irq_type = GB_GPIO_IRQ_TYPE_LEVEL_LOW;
break;
case IRQ_TYPE_LEVEL_HIGH:
irq_type = GB_GPIO_IRQ_TYPE_LEVEL_HIGH;
break;
default:
dev_err(chip->dev, "unsupported irq type: %u\n", type);
return -EINVAL;
}
line->irq_type = irq_type;
line->irq_type_pending = true;
return 0;
}
static void gb_gpio_irq_bus_lock(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
mutex_lock(&ggc->irq_lock);
}
static void gb_gpio_irq_bus_sync_unlock(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_to_gpio_chip(d);
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
struct gb_gpio_line *line = &ggc->lines[d->hwirq];
if (line->irq_type_pending) {
_gb_gpio_irq_set_type(ggc, d->hwirq, line->irq_type);
line->irq_type_pending = false;
}
if (line->masked_pending) {
if (line->masked)
_gb_gpio_irq_mask(ggc, d->hwirq);
else
_gb_gpio_irq_unmask(ggc, d->hwirq);
line->masked_pending = false;
}
mutex_unlock(&ggc->irq_lock);
}
static int gb_gpio_request_recv(u8 type, struct gb_operation *op)
{
struct gb_connection *connection = op->connection;
struct gb_gpio_controller *ggc = connection->private;
struct gb_message *request;
struct gb_gpio_irq_event_request *event;
int irq;
struct irq_desc *desc;
if (type != GB_GPIO_TYPE_IRQ_EVENT) {
dev_err(&connection->bundle->dev,
"unsupported unsolicited request: %u\n", type);
return -EINVAL;
}
request = op->request;
if (request->payload_size < sizeof(*event)) {
dev_err(ggc->chip.dev, "short event received (%zu < %zu)\n",
request->payload_size, sizeof(*event));
return -EINVAL;
}
event = request->payload;
if (event->which > ggc->line_max) {
dev_err(ggc->chip.dev, "invalid hw irq: %d\n", event->which);
return -EINVAL;
}
irq = irq_find_mapping(ggc->irqdomain, event->which);
if (!irq) {
dev_err(ggc->chip.dev, "failed to find IRQ\n");
return -EINVAL;
}
desc = irq_to_desc(irq);
if (!desc) {
dev_err(ggc->chip.dev, "failed to look up irq\n");
return -EINVAL;
}
local_irq_disable();
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0)
generic_handle_irq_desc(irq, desc);
#else
generic_handle_irq_desc(desc);
#endif
local_irq_enable();
return 0;
}
static int gb_gpio_request(struct gpio_chip *chip, unsigned offset)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
return gb_gpio_activate_operation(ggc, (u8)offset);
}
static void gb_gpio_free(struct gpio_chip *chip, unsigned offset)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
gb_gpio_deactivate_operation(ggc, (u8)offset);
}
static int gb_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
u8 which;
int ret;
which = (u8)offset;
ret = gb_gpio_get_direction_operation(ggc, which);
if (ret)
return ret;
return ggc->lines[which].direction ? 1 : 0;
}
static int gb_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
return gb_gpio_direction_in_operation(ggc, (u8)offset);
}
static int gb_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
return gb_gpio_direction_out_operation(ggc, (u8)offset, !!value);
}
static int gb_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
u8 which;
int ret;
which = (u8)offset;
ret = gb_gpio_get_value_operation(ggc, which);
if (ret)
return ret;
return ggc->lines[which].value;
}
static void gb_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
gb_gpio_set_value_operation(ggc, (u8)offset, !!value);
}
static int gb_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
unsigned debounce)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
u16 usec;
if (debounce > U16_MAX)
return -EINVAL;
usec = (u16)debounce;
return gb_gpio_set_debounce_operation(ggc, (u8)offset, usec);
}
static int gb_gpio_controller_setup(struct gb_gpio_controller *ggc)
{
int ret;
/* Now find out how many lines there are */
ret = gb_gpio_line_count_operation(ggc);
if (ret)
return ret;
ggc->lines = kcalloc(ggc->line_max + 1, sizeof(*ggc->lines),
GFP_KERNEL);
if (!ggc->lines)
return -ENOMEM;
return ret;
}
/**
* gb_gpio_irq_map() - maps an IRQ into a GB gpio irqchip
* @d: the irqdomain used by this irqchip
* @irq: the global irq number used by this GB gpio irqchip irq
* @hwirq: the local IRQ/GPIO line offset on this GB gpio
*
* This function will set up the mapping for a certain IRQ line on a
* GB gpio by assigning the GB gpio as chip data, and using the irqchip
* stored inside the GB gpio.
*/
static int gb_gpio_irq_map(struct irq_domain *domain, unsigned int irq,
irq_hw_number_t hwirq)
{
struct gpio_chip *chip = domain->host_data;
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
irq_set_chip_data(irq, ggc);
irq_set_chip_and_handler(irq, ggc->irqchip, ggc->irq_handler);
irq_set_noprobe(irq);
/*
* No set-up of the hardware will happen if IRQ_TYPE_NONE
* is passed as default type.
*/
if (ggc->irq_default_type != IRQ_TYPE_NONE)
irq_set_irq_type(irq, ggc->irq_default_type);
return 0;
}
static void gb_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
{
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
static const struct irq_domain_ops gb_gpio_domain_ops = {
.map = gb_gpio_irq_map,
.unmap = gb_gpio_irq_unmap,
};
/**
* gb_gpio_irqchip_remove() - removes an irqchip added to a gb_gpio_controller
* @ggc: the gb_gpio_controller to remove the irqchip from
*
* This is called only from gb_gpio_remove()
*/
static void gb_gpio_irqchip_remove(struct gb_gpio_controller *ggc)
{
unsigned int offset;
/* Remove all IRQ mappings and delete the domain */
if (ggc->irqdomain) {
for (offset = 0; offset < (ggc->line_max + 1); offset++)
irq_dispose_mapping(irq_find_mapping(ggc->irqdomain, offset));
irq_domain_remove(ggc->irqdomain);
}
if (ggc->irqchip) {
ggc->irqchip = NULL;
}
}
/**
* gb_gpio_irqchip_add() - adds an irqchip to a gpio chip
* @chip: the gpio chip to add the irqchip to
* @irqchip: the irqchip to add to the adapter
* @first_irq: if not dynamically assigned, the base (first) IRQ to
* allocate gpio irqs from
* @handler: the irq handler to use (often a predefined irq core function)
* @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE
* to have the core avoid setting up any default type in the hardware.
*
* This function closely associates a certain irqchip with a certain
* gpio chip, providing an irq domain to translate the local IRQs to
* global irqs, and making sure that the gpio chip
* is passed as chip data to all related functions. Driver callbacks
* need to use container_of() to get their local state containers back
* from the gpio chip passed as chip data. An irqdomain will be stored
* in the gpio chip that shall be used by the driver to handle IRQ number
* translation. The gpio chip will need to be initialized and registered
* before calling this function.
*/
static int gb_gpio_irqchip_add(struct gpio_chip *chip,
struct irq_chip *irqchip,
unsigned int first_irq,
irq_flow_handler_t handler,
unsigned int type)
{
struct gb_gpio_controller *ggc;
unsigned int offset;
unsigned irq_base;
if (!chip || !irqchip)
return -EINVAL;
ggc = gpio_chip_to_gb_gpio_controller(chip);
ggc->irqchip = irqchip;
ggc->irq_handler = handler;
ggc->irq_default_type = type;
ggc->irqdomain = irq_domain_add_simple(NULL,
ggc->line_max + 1, first_irq,
&gb_gpio_domain_ops, chip);
if (!ggc->irqdomain) {
ggc->irqchip = NULL;
return -EINVAL;
}
/*
* Prepare the mapping since the irqchip shall be orthogonal to
* any gpio calls. If the first_irq was zero, this is
* necessary to allocate descriptors for all IRQs.
*/
for (offset = 0; offset < (ggc->line_max + 1); offset++) {
irq_base = irq_create_mapping(ggc->irqdomain, offset);
if (offset == 0)
ggc->irq_base = irq_base;
}
return 0;
}
static int gb_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct gb_gpio_controller *ggc = gpio_chip_to_gb_gpio_controller(chip);
return irq_find_mapping(ggc->irqdomain, offset);
}
static int gb_gpio_connection_init(struct gb_connection *connection)
{
struct gb_gpio_controller *ggc;
struct gpio_chip *gpio;
struct irq_chip *irqc;
int ret;
ggc = kzalloc(sizeof(*ggc), GFP_KERNEL);
if (!ggc)
return -ENOMEM;
ggc->connection = connection;
connection->private = ggc;
ret = gb_gpio_controller_setup(ggc);
if (ret)
goto err_free_controller;
irqc = &ggc->irqc;
irqc->irq_mask = gb_gpio_irq_mask;
irqc->irq_unmask = gb_gpio_irq_unmask;
irqc->irq_set_type = gb_gpio_irq_set_type;
irqc->irq_bus_lock = gb_gpio_irq_bus_lock;
irqc->irq_bus_sync_unlock = gb_gpio_irq_bus_sync_unlock;
irqc->name = "greybus_gpio";
mutex_init(&ggc->irq_lock);
gpio = &ggc->chip;
gpio->label = "greybus_gpio";
gpio->dev = &connection->bundle->dev;
gpio->owner = THIS_MODULE;
gpio->request = gb_gpio_request;
gpio->free = gb_gpio_free;
gpio->get_direction = gb_gpio_get_direction;
gpio->direction_input = gb_gpio_direction_input;
gpio->direction_output = gb_gpio_direction_output;
gpio->get = gb_gpio_get;
gpio->set = gb_gpio_set;
gpio->set_debounce = gb_gpio_set_debounce;
gpio->to_irq = gb_gpio_to_irq;
gpio->base = -1; /* Allocate base dynamically */
gpio->ngpio = ggc->line_max + 1;
gpio->can_sleep = true;
ret = gpiochip_add(gpio);
if (ret) {
dev_err(&connection->bundle->dev,
"failed to add gpio chip: %d\n", ret);
goto err_free_lines;
}
ret = gb_gpio_irqchip_add(gpio, irqc, 0,
handle_level_irq, IRQ_TYPE_NONE);
if (ret) {
dev_err(&connection->bundle->dev,
"failed to add irq chip: %d\n", ret);
goto irqchip_err;
}
return 0;
irqchip_err:
gb_gpiochip_remove(gpio);
err_free_lines:
kfree(ggc->lines);
err_free_controller:
kfree(ggc);
return ret;
}
static void gb_gpio_connection_exit(struct gb_connection *connection)
{
struct gb_gpio_controller *ggc = connection->private;
if (!ggc)
return;
gb_gpio_irqchip_remove(ggc);
gb_gpiochip_remove(&ggc->chip);
/* kref_put(ggc->connection) */
kfree(ggc->lines);
kfree(ggc);
}
static struct gb_protocol gpio_protocol = {
.name = "gpio",
.id = GREYBUS_PROTOCOL_GPIO,
.major = GB_GPIO_VERSION_MAJOR,
.minor = GB_GPIO_VERSION_MINOR,
.connection_init = gb_gpio_connection_init,
.connection_exit = gb_gpio_connection_exit,
.request_recv = gb_gpio_request_recv,
};
gb_builtin_protocol_driver(gpio_protocol);