blob: 55ffcd7c42e27aff526eeef371f627ec4c50faf9 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/*
* SPI interface.
*
* Copyright (c) 2017-2020, Silicon Laboratories, Inc.
* Copyright (c) 2011, Sagrad Inc.
* Copyright (c) 2010, ST-Ericsson
*/
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/spi/spi.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/of.h>
#include "bus.h"
#include "wfx.h"
#include "hwio.h"
#include "main.h"
#include "bh.h"
#define SET_WRITE 0x7FFF /* usage: and operation */
#define SET_READ 0x8000 /* usage: or operation */
#define WFX_RESET_INVERTED 1
static const struct wfx_platform_data wfx_spi_pdata = {
.file_fw = "wfm_wf200",
.file_pds = "wf200.pds",
.use_rising_clk = true,
};
struct wfx_spi_priv {
struct spi_device *func;
struct wfx_dev *core;
struct gpio_desc *gpio_reset;
bool need_swab;
};
/* The chip reads 16bits of data at time and place them directly into (little
* endian) CPU register. So, the chip expects bytes order to be "B1 B0 B3 B2"
* (while LE is "B0 B1 B2 B3" and BE is "B3 B2 B1 B0")
*
* A little endian host with bits_per_word == 16 should do the right job
* natively. The code below to support big endian host and commonly used SPI
* 8bits.
*/
static int wfx_spi_copy_from_io(void *priv, unsigned int addr,
void *dst, size_t count)
{
struct wfx_spi_priv *bus = priv;
u16 regaddr = (addr << 12) | (count / 2) | SET_READ;
struct spi_message m;
struct spi_transfer t_addr = {
.tx_buf = &regaddr,
.len = sizeof(regaddr),
};
struct spi_transfer t_msg = {
.rx_buf = dst,
.len = count,
};
u16 *dst16 = dst;
int ret, i;
WARN(count % 2, "buffer size must be a multiple of 2");
cpu_to_le16s(&regaddr);
if (bus->need_swab)
swab16s(&regaddr);
spi_message_init(&m);
spi_message_add_tail(&t_addr, &m);
spi_message_add_tail(&t_msg, &m);
ret = spi_sync(bus->func, &m);
if (bus->need_swab && addr == WFX_REG_CONFIG)
for (i = 0; i < count / 2; i++)
swab16s(&dst16[i]);
return ret;
}
static int wfx_spi_copy_to_io(void *priv, unsigned int addr,
const void *src, size_t count)
{
struct wfx_spi_priv *bus = priv;
u16 regaddr = (addr << 12) | (count / 2);
/* FIXME: use a bounce buffer */
u16 *src16 = (void *)src;
int ret, i;
struct spi_message m;
struct spi_transfer t_addr = {
.tx_buf = &regaddr,
.len = sizeof(regaddr),
};
struct spi_transfer t_msg = {
.tx_buf = src,
.len = count,
};
WARN(count % 2, "buffer size must be a multiple of 2");
WARN(regaddr & SET_READ, "bad addr or size overflow");
cpu_to_le16s(&regaddr);
/* Register address and CONFIG content always use 16bit big endian
* ("BADC" order)
*/
if (bus->need_swab)
swab16s(&regaddr);
if (bus->need_swab && addr == WFX_REG_CONFIG)
for (i = 0; i < count / 2; i++)
swab16s(&src16[i]);
spi_message_init(&m);
spi_message_add_tail(&t_addr, &m);
spi_message_add_tail(&t_msg, &m);
ret = spi_sync(bus->func, &m);
if (bus->need_swab && addr == WFX_REG_CONFIG)
for (i = 0; i < count / 2; i++)
swab16s(&src16[i]);
return ret;
}
static void wfx_spi_lock(void *priv)
{
}
static void wfx_spi_unlock(void *priv)
{
}
static irqreturn_t wfx_spi_irq_handler(int irq, void *priv)
{
struct wfx_spi_priv *bus = priv;
wfx_bh_request_rx(bus->core);
return IRQ_HANDLED;
}
static int wfx_spi_irq_subscribe(void *priv)
{
struct wfx_spi_priv *bus = priv;
u32 flags;
flags = irq_get_trigger_type(bus->func->irq);
if (!flags)
flags = IRQF_TRIGGER_HIGH;
flags |= IRQF_ONESHOT;
return devm_request_threaded_irq(&bus->func->dev, bus->func->irq, NULL,
wfx_spi_irq_handler, IRQF_ONESHOT,
"wfx", bus);
}
static int wfx_spi_irq_unsubscribe(void *priv)
{
struct wfx_spi_priv *bus = priv;
devm_free_irq(&bus->func->dev, bus->func->irq, bus);
return 0;
}
static size_t wfx_spi_align_size(void *priv, size_t size)
{
/* Most of SPI controllers avoid DMA if buffer size is not 32bit aligned
*/
return ALIGN(size, 4);
}
static const struct hwbus_ops wfx_spi_hwbus_ops = {
.copy_from_io = wfx_spi_copy_from_io,
.copy_to_io = wfx_spi_copy_to_io,
.irq_subscribe = wfx_spi_irq_subscribe,
.irq_unsubscribe = wfx_spi_irq_unsubscribe,
.lock = wfx_spi_lock,
.unlock = wfx_spi_unlock,
.align_size = wfx_spi_align_size,
};
static int wfx_spi_probe(struct spi_device *func)
{
struct wfx_spi_priv *bus;
int ret;
if (!func->bits_per_word)
func->bits_per_word = 16;
ret = spi_setup(func);
if (ret)
return ret;
/* Trace below is also displayed by spi_setup() if compiled with DEBUG */
dev_dbg(&func->dev, "SPI params: CS=%d, mode=%d bits/word=%d speed=%d\n",
func->chip_select, func->mode, func->bits_per_word,
func->max_speed_hz);
if (func->bits_per_word != 16 && func->bits_per_word != 8)
dev_warn(&func->dev, "unusual bits/word value: %d\n",
func->bits_per_word);
if (func->max_speed_hz > 50000000)
dev_warn(&func->dev, "%dHz is a very high speed\n",
func->max_speed_hz);
bus = devm_kzalloc(&func->dev, sizeof(*bus), GFP_KERNEL);
if (!bus)
return -ENOMEM;
bus->func = func;
if (func->bits_per_word == 8 || IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
bus->need_swab = true;
spi_set_drvdata(func, bus);
bus->gpio_reset = devm_gpiod_get_optional(&func->dev, "reset",
GPIOD_OUT_LOW);
if (IS_ERR(bus->gpio_reset))
return PTR_ERR(bus->gpio_reset);
if (!bus->gpio_reset) {
dev_warn(&func->dev,
"gpio reset is not defined, trying to load firmware anyway\n");
} else {
gpiod_set_consumer_name(bus->gpio_reset, "wfx reset");
if (spi_get_device_id(func)->driver_data & WFX_RESET_INVERTED)
gpiod_toggle_active_low(bus->gpio_reset);
gpiod_set_value_cansleep(bus->gpio_reset, 1);
usleep_range(100, 150);
gpiod_set_value_cansleep(bus->gpio_reset, 0);
usleep_range(2000, 2500);
}
bus->core = wfx_init_common(&func->dev, &wfx_spi_pdata,
&wfx_spi_hwbus_ops, bus);
if (!bus->core)
return -EIO;
return wfx_probe(bus->core);
}
static int wfx_spi_remove(struct spi_device *func)
{
struct wfx_spi_priv *bus = spi_get_drvdata(func);
wfx_release(bus->core);
return 0;
}
/* For dynamic driver binding, kernel does not use OF to match driver. It only
* use modalias and modalias is a copy of 'compatible' DT node with vendor
* stripped.
*/
static const struct spi_device_id wfx_spi_id[] = {
{ "wfx-spi", WFX_RESET_INVERTED },
{ "wf200", 0 },
{ },
};
MODULE_DEVICE_TABLE(spi, wfx_spi_id);
#ifdef CONFIG_OF
static const struct of_device_id wfx_spi_of_match[] = {
{ .compatible = "silabs,wfx-spi", .data = (void *)WFX_RESET_INVERTED },
{ .compatible = "silabs,wf200" },
{ },
};
MODULE_DEVICE_TABLE(of, wfx_spi_of_match);
#endif
struct spi_driver wfx_spi_driver = {
.driver = {
.name = "wfx-spi",
.of_match_table = of_match_ptr(wfx_spi_of_match),
},
.id_table = wfx_spi_id,
.probe = wfx_spi_probe,
.remove = wfx_spi_remove,
};