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a86854d0c5
linux/drivers/spi/spi-gpio.c
Kees Cook a86854d0c5 treewide: devm_kzalloc() -> devm_kcalloc() 
The devm_kzalloc() function has a 2-factor argument form, devm_kcalloc().
This patch replaces cases of:

        devm_kzalloc(handle, a * b, gfp)

with:
        devm_kcalloc(handle, a * b, gfp)

as well as handling cases of:

        devm_kzalloc(handle, a * b * c, gfp)

with:

        devm_kzalloc(handle, array3_size(a, b, c), gfp)

as it's slightly less ugly than:

        devm_kcalloc(handle, array_size(a, b), c, gfp)

This does, however, attempt to ignore constant size factors like:

        devm_kzalloc(handle, 4 * 1024, gfp)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

Some manual whitespace fixes were needed in this patch, as Coccinelle
really liked to write "=devm_kcalloc..." instead of "= devm_kcalloc...".

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
expression HANDLE;
type TYPE;
expression THING, E;
@@

(
  devm_kzalloc(HANDLE,
-	(sizeof(TYPE)) * E
+	sizeof(TYPE) * E
  , ...)
|
  devm_kzalloc(HANDLE,
-	(sizeof(THING)) * E
+	sizeof(THING) * E
  , ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression HANDLE;
expression COUNT;
typedef u8;
typedef __u8;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(u8) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(__u8) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(char) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(unsigned char) * (COUNT)
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(u8) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(__u8) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(char) * COUNT
+	COUNT
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(unsigned char) * COUNT
+	COUNT
  , ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
expression HANDLE;
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (COUNT_ID)
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * COUNT_ID
+	COUNT_ID, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (COUNT_CONST)
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * COUNT_CONST
+	COUNT_CONST, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (COUNT_ID)
+	COUNT_ID, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * COUNT_ID
+	COUNT_ID, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (COUNT_CONST)
+	COUNT_CONST, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * COUNT_CONST
+	COUNT_CONST, sizeof(THING)
  , ...)
)

// 2-factor product, only identifiers.
@@
expression HANDLE;
identifier SIZE, COUNT;
@@

- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	SIZE * COUNT
+	COUNT, SIZE
  , ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression HANDLE;
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(TYPE))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * (COUNT) * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * COUNT * (STRIDE)
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING) * COUNT * STRIDE
+	array3_size(COUNT, STRIDE, sizeof(THING))
  , ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression HANDLE;
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(THING1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(THING1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * COUNT
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
|
  devm_kzalloc(HANDLE,
-	sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+	array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
  , ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
expression HANDLE;
identifier STRIDE, SIZE, COUNT;
@@

(
  devm_kzalloc(HANDLE,
-	(COUNT) * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * (STRIDE) * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * STRIDE * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(COUNT) * (STRIDE) * (SIZE)
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
|
  devm_kzalloc(HANDLE,
-	COUNT * STRIDE * SIZE
+	array3_size(COUNT, STRIDE, SIZE)
  , ...)
)

// Any remaining multi-factor products, first at least 3-factor products,
// when they're not all constants...
@@
expression HANDLE;
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
  devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * (E2) * E3
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	(E1) * (E2) * (E3)
+	array3_size(E1, E2, E3)
  , ...)
|
  devm_kzalloc(HANDLE,
-	E1 * E2 * E3
+	array3_size(E1, E2, E3)
  , ...)
)

// And then all remaining 2 factors products when they're not all constants,
// keeping sizeof() as the second factor argument.
@@
expression HANDLE;
expression THING, E1, E2;
type TYPE;
constant C1, C2, C3;
@@

(
  devm_kzalloc(HANDLE, sizeof(THING) * C2, ...)
|
  devm_kzalloc(HANDLE, sizeof(TYPE) * C2, ...)
|
  devm_kzalloc(HANDLE, C1 * C2 * C3, ...)
|
  devm_kzalloc(HANDLE, C1 * C2, ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * (E2)
+	E2, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(TYPE) * E2
+	E2, sizeof(TYPE)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * (E2)
+	E2, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	sizeof(THING) * E2
+	E2, sizeof(THING)
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	(E1) * E2
+	E1, E2
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	(E1) * (E2)
+	E1, E2
  , ...)
|
- devm_kzalloc
+ devm_kcalloc
  (HANDLE,
-	E1 * E2
+	E1, E2
  , ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 16:19:22 -07:00

463 lines
13 KiB
C
Raw Blame History

/*
* SPI master driver using generic bitbanged GPIO
*
* Copyright (C) 2006,2008 David Brownell
* Copyright (C) 2017 Linus Walleij
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/spi/spi_gpio.h>
/*
* This bitbanging SPI master driver should help make systems usable
* when a native hardware SPI engine is not available, perhaps because
* its driver isn't yet working or because the I/O pins it requires
* are used for other purposes.
*
* platform_device->driver_data ... points to spi_gpio
*
* spi->controller_state ... reserved for bitbang framework code
* spi->controller_data ... holds chipselect GPIO
*
* spi->master->dev.driver_data ... points to spi_gpio->bitbang
*/
struct spi_gpio {
struct spi_bitbang bitbang;
struct spi_gpio_platform_data pdata;
struct platform_device *pdev;
struct gpio_desc *sck;
struct gpio_desc *miso;
struct gpio_desc *mosi;
struct gpio_desc **cs_gpios;
bool has_cs;
};
/*----------------------------------------------------------------------*/
/*
* Because the overhead of going through four GPIO procedure calls
* per transferred bit can make performance a problem, this code
* is set up so that you can use it in either of two ways:
*
* - The slow generic way: set up platform_data to hold the GPIO
* numbers used for MISO/MOSI/SCK, and issue procedure calls for
* each of them. This driver can handle several such busses.
*
* - The quicker inlined way: only helps with platform GPIO code
* that inlines operations for constant GPIOs. This can give
* you tight (fast!) inner loops, but each such bus needs a
* new driver. You'll define a new C file, with Makefile and
* Kconfig support; the C code can be a total of six lines:
*
* #define DRIVER_NAME "myboard_spi2"
* #define SPI_MISO_GPIO 119
* #define SPI_MOSI_GPIO 120
* #define SPI_SCK_GPIO 121
* #define SPI_N_CHIPSEL 4
* #include "spi-gpio.c"
*/
#ifndef DRIVER_NAME
#define DRIVER_NAME "spi_gpio"
#define GENERIC_BITBANG /* vs tight inlines */
#endif
/*----------------------------------------------------------------------*/
static inline struct spi_gpio *__pure
spi_to_spi_gpio(const struct spi_device *spi)
{
const struct spi_bitbang *bang;
struct spi_gpio *spi_gpio;
bang = spi_master_get_devdata(spi->master);
spi_gpio = container_of(bang, struct spi_gpio, bitbang);
return spi_gpio;
}
static inline struct spi_gpio_platform_data *__pure
spi_to_pdata(const struct spi_device *spi)
{
return &spi_to_spi_gpio(spi)->pdata;
}
/* These helpers are in turn called by the bitbang inlines */
static inline void setsck(const struct spi_device *spi, int is_on)
{
struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
gpiod_set_value_cansleep(spi_gpio->sck, is_on);
}
static inline void setmosi(const struct spi_device *spi, int is_on)
{
struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
gpiod_set_value_cansleep(spi_gpio->mosi, is_on);
}
static inline int getmiso(const struct spi_device *spi)
{
struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
return !!gpiod_get_value_cansleep(spi_gpio->miso);
}
/*
* NOTE: this clocks "as fast as we can". It "should" be a function of the
* requested device clock. Software overhead means we usually have trouble
* reaching even one Mbit/sec (except when we can inline bitops), so for now
* we'll just assume we never need additional per-bit slowdowns.
*/
#define spidelay(nsecs) do {} while (0)
#include "spi-bitbang-txrx.h"
/*
* These functions can leverage inline expansion of GPIO calls to shrink
* costs for a txrx bit, often by factors of around ten (by instruction
* count). That is particularly visible for larger word sizes, but helps
* even with default 8-bit words.
*
* REVISIT overheads calling these functions for each word also have
* significant performance costs. Having txrx_bufs() calls that inline
* the txrx_word() logic would help performance, e.g. on larger blocks
* used with flash storage or MMC/SD. There should also be ways to make
* GCC be less stupid about reloading registers inside the I/O loops,
* even without inlined GPIO calls; __attribute__((hot)) on GCC 4.3?
*/
static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha0(spi, nsecs, 0, 0, word, bits);
}
static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha1(spi, nsecs, 0, 0, word, bits);
}
static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha0(spi, nsecs, 1, 0, word, bits);
}
static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
return bitbang_txrx_be_cpha1(spi, nsecs, 1, 0, word, bits);
}
/*
* These functions do not call setmosi or getmiso if respective flag
* (SPI_MASTER_NO_RX or SPI_MASTER_NO_TX) is set, so they are safe to
* call when such pin is not present or defined in the controller.
* A separate set of callbacks is defined to get highest possible
* speed in the generic case (when both MISO and MOSI lines are
* available), as optimiser will remove the checks when argument is
* constant.
*/
static u32 spi_gpio_spec_txrx_word_mode0(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
unsigned flags = spi->master->flags;
return bitbang_txrx_be_cpha0(spi, nsecs, 0, flags, word, bits);
}
static u32 spi_gpio_spec_txrx_word_mode1(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
unsigned flags = spi->master->flags;
return bitbang_txrx_be_cpha1(spi, nsecs, 0, flags, word, bits);
}
static u32 spi_gpio_spec_txrx_word_mode2(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
unsigned flags = spi->master->flags;
return bitbang_txrx_be_cpha0(spi, nsecs, 1, flags, word, bits);
}
static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
unsigned flags = spi->master->flags;
return bitbang_txrx_be_cpha1(spi, nsecs, 1, flags, word, bits);
}
/*----------------------------------------------------------------------*/
static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
{
struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
/* set initial clock line level */
if (is_active)
gpiod_set_value_cansleep(spi_gpio->sck, spi->mode & SPI_CPOL);
/* Drive chip select line, if we have one */
if (spi_gpio->has_cs) {
struct gpio_desc *cs = spi_gpio->cs_gpios[spi->chip_select];
/* SPI chip selects are normally active-low */
gpiod_set_value_cansleep(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active);
}
}
static int spi_gpio_setup(struct spi_device *spi)
{
struct gpio_desc *cs;
int status = 0;
struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
/*
* The CS GPIOs have already been
* initialized from the descriptor lookup.
*/
cs = spi_gpio->cs_gpios[spi->chip_select];
if (!spi->controller_state && cs)
status = gpiod_direction_output(cs,
!(spi->mode & SPI_CS_HIGH));
if (!status)
status = spi_bitbang_setup(spi);
return status;
}
static void spi_gpio_cleanup(struct spi_device *spi)
{
spi_bitbang_cleanup(spi);
}
/*
* It can be convenient to use this driver with pins that have alternate
* functions associated with a "native" SPI controller if a driver for that
* controller is not available, or is missing important functionality.
*
* On platforms which can do so, configure MISO with a weak pullup unless
* there's an external pullup on that signal. That saves power by avoiding
* floating signals. (A weak pulldown would save power too, but many
* drivers expect to see all-ones data as the no slave "response".)
*/
static int spi_gpio_request(struct device *dev,
struct spi_gpio *spi_gpio,
unsigned int num_chipselects,
u16 *mflags)
{
int i;
spi_gpio->mosi = devm_gpiod_get_optional(dev, "mosi", GPIOD_OUT_LOW);
if (IS_ERR(spi_gpio->mosi))
return PTR_ERR(spi_gpio->mosi);
if (!spi_gpio->mosi)
/* HW configuration without MOSI pin */
*mflags |= SPI_MASTER_NO_TX;
spi_gpio->miso = devm_gpiod_get_optional(dev, "miso", GPIOD_IN);
if (IS_ERR(spi_gpio->miso))
return PTR_ERR(spi_gpio->miso);
if (!spi_gpio->miso)
/* HW configuration without MISO pin */
*mflags |= SPI_MASTER_NO_RX;
spi_gpio->sck = devm_gpiod_get(dev, "sck", GPIOD_OUT_LOW);
if (IS_ERR(spi_gpio->mosi))
return PTR_ERR(spi_gpio->mosi);
for (i = 0; i < num_chipselects; i++) {
spi_gpio->cs_gpios[i] = devm_gpiod_get_index(dev, "cs",
i, GPIOD_OUT_HIGH);
if (IS_ERR(spi_gpio->cs_gpios[i]))
return PTR_ERR(spi_gpio->cs_gpios[i]);
}
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id spi_gpio_dt_ids[] = {
{ .compatible = "spi-gpio" },
{}
};
MODULE_DEVICE_TABLE(of, spi_gpio_dt_ids);
static int spi_gpio_probe_dt(struct platform_device *pdev)
{
int ret;
u32 tmp;
struct spi_gpio_platform_data *pdata;
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id =
of_match_device(spi_gpio_dt_ids, &pdev->dev);
if (!of_id)
return 0;
pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
if (!pdata)
return -ENOMEM;
ret = of_property_read_u32(np, "num-chipselects", &tmp);
if (ret < 0) {
dev_err(&pdev->dev, "num-chipselects property not found\n");
goto error_free;
}
pdata->num_chipselect = tmp;
pdev->dev.platform_data = pdata;
return 1;
error_free:
devm_kfree(&pdev->dev, pdata);
return ret;
}
#else
static inline int spi_gpio_probe_dt(struct platform_device *pdev)
{
return 0;
}
#endif
static int spi_gpio_probe(struct platform_device *pdev)
{
int status;
struct spi_master *master;
struct spi_gpio *spi_gpio;
struct spi_gpio_platform_data *pdata;
u16 master_flags = 0;
bool use_of = 0;
status = spi_gpio_probe_dt(pdev);
if (status < 0)
return status;
if (status > 0)
use_of = 1;
pdata = dev_get_platdata(&pdev->dev);
#ifdef GENERIC_BITBANG
if (!pdata || (!use_of && !pdata->num_chipselect))
return -ENODEV;
#endif
master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio));
if (!master)
return -ENOMEM;
spi_gpio = spi_master_get_devdata(master);
spi_gpio->cs_gpios = devm_kcalloc(&pdev->dev,
pdata->num_chipselect,
sizeof(*spi_gpio->cs_gpios),
GFP_KERNEL);
if (!spi_gpio->cs_gpios)
return -ENOMEM;
platform_set_drvdata(pdev, spi_gpio);
/* Determine if we have chip selects connected */
spi_gpio->has_cs = !!pdata->num_chipselect;
spi_gpio->pdev = pdev;
if (pdata)
spi_gpio->pdata = *pdata;
status = spi_gpio_request(&pdev->dev, spi_gpio,
pdata->num_chipselect, &master_flags);
if (status)
return status;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
master->flags = master_flags;
master->bus_num = pdev->id;
/* The master needs to think there is a chipselect even if not connected */
master->num_chipselect = spi_gpio->has_cs ? pdata->num_chipselect : 1;
master->setup = spi_gpio_setup;
master->cleanup = spi_gpio_cleanup;
#ifdef CONFIG_OF
master->dev.of_node = pdev->dev.of_node;
#endif
spi_gpio->bitbang.master = master;
spi_gpio->bitbang.chipselect = spi_gpio_chipselect;
if ((master_flags & (SPI_MASTER_NO_TX | SPI_MASTER_NO_RX)) == 0) {
spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0;
spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1;
spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
} else {
spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_spec_txrx_word_mode0;
spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_spec_txrx_word_mode1;
spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_spec_txrx_word_mode2;
spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_spec_txrx_word_mode3;
}
spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
spi_gpio->bitbang.flags = SPI_CS_HIGH;
status = spi_bitbang_start(&spi_gpio->bitbang);
if (status)
spi_master_put(master);
return status;
}
static int spi_gpio_remove(struct platform_device *pdev)
{
struct spi_gpio *spi_gpio;
struct spi_gpio_platform_data *pdata;
spi_gpio = platform_get_drvdata(pdev);
pdata = dev_get_platdata(&pdev->dev);
/* stop() unregisters child devices too */
spi_bitbang_stop(&spi_gpio->bitbang);
spi_master_put(spi_gpio->bitbang.master);
return 0;
}
MODULE_ALIAS("platform:" DRIVER_NAME);
static struct platform_driver spi_gpio_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = of_match_ptr(spi_gpio_dt_ids),
},
.probe = spi_gpio_probe,
.remove = spi_gpio_remove,
};
module_platform_driver(spi_gpio_driver);
MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO ");
MODULE_AUTHOR("David Brownell");
MODULE_LICENSE("GPL");
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