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linux/drivers/spi/spi-sc18is602.c
Rob Herring 749396cb29
spi: Explicitly include correct DT includes 
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230714174955.4064174-1-robh@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2023-07-14 20:53:00 +01:00

348 lines
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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* NXP SC18IS602/603 SPI driver
*
* Copyright (C) Guenter Roeck <linux@roeck-us.net>
*/
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include <linux/platform_data/sc18is602.h>
#include <linux/gpio/consumer.h>
enum chips { sc18is602, sc18is602b, sc18is603 };
#define SC18IS602_BUFSIZ 200
#define SC18IS602_CLOCK 7372000
#define SC18IS602_MODE_CPHA BIT(2)
#define SC18IS602_MODE_CPOL BIT(3)
#define SC18IS602_MODE_LSB_FIRST BIT(5)
#define SC18IS602_MODE_CLOCK_DIV_4 0x0
#define SC18IS602_MODE_CLOCK_DIV_16 0x1
#define SC18IS602_MODE_CLOCK_DIV_64 0x2
#define SC18IS602_MODE_CLOCK_DIV_128 0x3
struct sc18is602 {
struct spi_master *master;
struct device *dev;
u8 ctrl;
u32 freq;
u32 speed;
/* I2C data */
struct i2c_client *client;
enum chips id;
u8 buffer[SC18IS602_BUFSIZ + 1];
int tlen; /* Data queued for tx in buffer */
int rindex; /* Receive data index in buffer */
struct gpio_desc *reset;
};
static int sc18is602_wait_ready(struct sc18is602 *hw, int len)
{
int i, err;
int usecs = 1000000 * len / hw->speed + 1;
u8 dummy[1];
for (i = 0; i < 10; i++) {
err = i2c_master_recv(hw->client, dummy, 1);
if (err >= 0)
return 0;
usleep_range(usecs, usecs * 2);
}
return -ETIMEDOUT;
}
static int sc18is602_txrx(struct sc18is602 *hw, struct spi_message *msg,
struct spi_transfer *t, bool do_transfer)
{
unsigned int len = t->len;
int ret;
if (hw->tlen == 0) {
/* First byte (I2C command) is chip select */
hw->buffer[0] = 1 << spi_get_chipselect(msg->spi, 0);
hw->tlen = 1;
hw->rindex = 0;
}
/*
* We can not immediately send data to the chip, since each I2C message
* resembles a full SPI message (from CS active to CS inactive).
* Enqueue messages up to the first read or until do_transfer is true.
*/
if (t->tx_buf) {
memcpy(&hw->buffer[hw->tlen], t->tx_buf, len);
hw->tlen += len;
if (t->rx_buf)
do_transfer = true;
else
hw->rindex = hw->tlen - 1;
} else if (t->rx_buf) {
/*
* For receive-only transfers we still need to perform a dummy
* write to receive data from the SPI chip.
* Read data starts at the end of transmit data (minus 1 to
* account for CS).
*/
hw->rindex = hw->tlen - 1;
memset(&hw->buffer[hw->tlen], 0, len);
hw->tlen += len;
do_transfer = true;
}
if (do_transfer && hw->tlen > 1) {
ret = sc18is602_wait_ready(hw, SC18IS602_BUFSIZ);
if (ret < 0)
return ret;
ret = i2c_master_send(hw->client, hw->buffer, hw->tlen);
if (ret < 0)
return ret;
if (ret != hw->tlen)
return -EIO;
if (t->rx_buf) {
int rlen = hw->rindex + len;
ret = sc18is602_wait_ready(hw, hw->tlen);
if (ret < 0)
return ret;
ret = i2c_master_recv(hw->client, hw->buffer, rlen);
if (ret < 0)
return ret;
if (ret != rlen)
return -EIO;
memcpy(t->rx_buf, &hw->buffer[hw->rindex], len);
}
hw->tlen = 0;
}
return len;
}
static int sc18is602_setup_transfer(struct sc18is602 *hw, u32 hz, u8 mode)
{
u8 ctrl = 0;
int ret;
if (mode & SPI_CPHA)
ctrl |= SC18IS602_MODE_CPHA;
if (mode & SPI_CPOL)
ctrl |= SC18IS602_MODE_CPOL;
if (mode & SPI_LSB_FIRST)
ctrl |= SC18IS602_MODE_LSB_FIRST;
/* Find the closest clock speed */
if (hz >= hw->freq / 4) {
ctrl |= SC18IS602_MODE_CLOCK_DIV_4;
hw->speed = hw->freq / 4;
} else if (hz >= hw->freq / 16) {
ctrl |= SC18IS602_MODE_CLOCK_DIV_16;
hw->speed = hw->freq / 16;
} else if (hz >= hw->freq / 64) {
ctrl |= SC18IS602_MODE_CLOCK_DIV_64;
hw->speed = hw->freq / 64;
} else {
ctrl |= SC18IS602_MODE_CLOCK_DIV_128;
hw->speed = hw->freq / 128;
}
/*
* Don't do anything if the control value did not change. The initial
* value of 0xff for hw->ctrl ensures that the correct mode will be set
* with the first call to this function.
*/
if (ctrl == hw->ctrl)
return 0;
ret = i2c_smbus_write_byte_data(hw->client, 0xf0, ctrl);
if (ret < 0)
return ret;
hw->ctrl = ctrl;
return 0;
}
static int sc18is602_check_transfer(struct spi_device *spi,
struct spi_transfer *t, int tlen)
{
if (t && t->len + tlen > SC18IS602_BUFSIZ + 1)
return -EINVAL;
return 0;
}
static int sc18is602_transfer_one(struct spi_master *master,
struct spi_message *m)
{
struct sc18is602 *hw = spi_master_get_devdata(master);
struct spi_device *spi = m->spi;
struct spi_transfer *t;
int status = 0;
hw->tlen = 0;
list_for_each_entry(t, &m->transfers, transfer_list) {
bool do_transfer;
status = sc18is602_check_transfer(spi, t, hw->tlen);
if (status < 0)
break;
status = sc18is602_setup_transfer(hw, t->speed_hz, spi->mode);
if (status < 0)
break;
do_transfer = t->cs_change || list_is_last(&t->transfer_list,
&m->transfers);
if (t->len) {
status = sc18is602_txrx(hw, m, t, do_transfer);
if (status < 0)
break;
m->actual_length += status;
}
status = 0;
spi_transfer_delay_exec(t);
}
m->status = status;
spi_finalize_current_message(master);
return status;
}
static size_t sc18is602_max_transfer_size(struct spi_device *spi)
{
return SC18IS602_BUFSIZ;
}
static int sc18is602_setup(struct spi_device *spi)
{
struct sc18is602 *hw = spi_master_get_devdata(spi->master);
/* SC18IS602 does not support CS2 */
if (hw->id == sc18is602 && (spi_get_chipselect(spi, 0) == 2))
return -ENXIO;
return 0;
}
static int sc18is602_probe(struct i2c_client *client)
{
const struct i2c_device_id *id = i2c_client_get_device_id(client);
struct device *dev = &client->dev;
struct device_node *np = dev->of_node;
struct sc18is602_platform_data *pdata = dev_get_platdata(dev);
struct sc18is602 *hw;
struct spi_master *master;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
return -EINVAL;
master = devm_spi_alloc_master(dev, sizeof(struct sc18is602));
if (!master)
return -ENOMEM;
hw = spi_master_get_devdata(master);
i2c_set_clientdata(client, hw);
/* assert reset and then release */
hw->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
if (IS_ERR(hw->reset))
return PTR_ERR(hw->reset);
gpiod_set_value_cansleep(hw->reset, 0);
hw->master = master;
hw->client = client;
hw->dev = dev;
hw->ctrl = 0xff;
if (client->dev.of_node)
hw->id = (enum chips)of_device_get_match_data(&client->dev);
else
hw->id = id->driver_data;
switch (hw->id) {
case sc18is602:
case sc18is602b:
master->num_chipselect = 4;
hw->freq = SC18IS602_CLOCK;
break;
case sc18is603:
master->num_chipselect = 2;
if (pdata) {
hw->freq = pdata->clock_frequency;
} else {
const __be32 *val;
int len;
val = of_get_property(np, "clock-frequency", &len);
if (val && len >= sizeof(__be32))
hw->freq = be32_to_cpup(val);
}
if (!hw->freq)
hw->freq = SC18IS602_CLOCK;
break;
}
master->bus_num = np ? -1 : client->adapter->nr;
master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_LSB_FIRST;
master->bits_per_word_mask = SPI_BPW_MASK(8);
master->setup = sc18is602_setup;
master->transfer_one_message = sc18is602_transfer_one;
master->max_transfer_size = sc18is602_max_transfer_size;
master->max_message_size = sc18is602_max_transfer_size;
master->dev.of_node = np;
master->min_speed_hz = hw->freq / 128;
master->max_speed_hz = hw->freq / 4;
return devm_spi_register_master(dev, master);
}
static const struct i2c_device_id sc18is602_id[] = {
{ "sc18is602", sc18is602 },
{ "sc18is602b", sc18is602b },
{ "sc18is603", sc18is603 },
{ }
};
MODULE_DEVICE_TABLE(i2c, sc18is602_id);
static const struct of_device_id sc18is602_of_match[] __maybe_unused = {
{
.compatible = "nxp,sc18is602",
.data = (void *)sc18is602
},
{
.compatible = "nxp,sc18is602b",
.data = (void *)sc18is602b
},
{
.compatible = "nxp,sc18is603",
.data = (void *)sc18is603
},
{ },
};
MODULE_DEVICE_TABLE(of, sc18is602_of_match);
static struct i2c_driver sc18is602_driver = {
.driver = {
.name = "sc18is602",
.of_match_table = of_match_ptr(sc18is602_of_match),
},
.probe = sc18is602_probe,
.id_table = sc18is602_id,
};
module_i2c_driver(sc18is602_driver);
MODULE_DESCRIPTION("SC18IS602/603 SPI Master Driver");
MODULE_AUTHOR("Guenter Roeck");
MODULE_LICENSE("GPL");
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