Commit 23b4f8b1 authored by Linus Walleij's avatar Linus Walleij Committed by Olof Johansson
Browse files

ARM: u300: Delete dummy SPI chip 



It's been told to me a few times that this kernel module
should not exist, instead we should use the loopback test
from userspace if need be. If a kernel module is required
for testing SPI, it should be generic and put in
drivers/spi/*.

Delete this driver.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
parent 57361846

arch/arm/mach-u300/Kconfig

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Original line number Diff line number Diff line
@@ -29,17 +29,4 @@ config U300_DEBUG 
	help

		Debug support for U300 in sysfs, procfs etc.



config MACH_U300_SPIDUMMY

	depends on ARCH_U300

	bool "SSP/SPI dummy chip"

	select SPI

	select SPI_MASTER

	select SPI_PL022

	help

		This creates a small kernel module that creates a dummy

		SPI device to be used for loopback tests. Regularly used

		to test reference designs. If you're not testing SPI,

		you don't need it. Selecting this will activate the

		SPI framework and ARM PL022 support.



endif

arch/arm/mach-u300/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -4,5 +4,4 @@ 


obj-y		:= core.o



obj-$(CONFIG_MACH_U300_SPIDUMMY)  += dummyspichip.o

obj-$(CONFIG_REGULATOR_AB3100)    += regulator.o

arch/arm/mach-u300/dummyspichip.c

deleted100644 → 0
+0 −276
Original line number Diff line number Diff line 
/*

 * arch/arm/mach-u300/dummyspichip.c

 *

 * Copyright (C) 2007-2009 ST-Ericsson AB

 * License terms: GNU General Public License (GPL) version 2

 * This is a dummy loopback SPI "chip" used for testing SPI.

 * Author: Linus Walleij <linus.walleij@stericsson.com>

 */

#include <linux/init.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/device.h>

#include <linux/err.h>

#include <linux/sysfs.h>

#include <linux/mutex.h>

#include <linux/spi/spi.h>

#include <linux/dma-mapping.h>

#include <linux/slab.h>

/*

 * WARNING! Do not include this pl022-specific controller header

 * for any generic driver. It is only done in this dummy chip

 * because we alter the chip configuration in order to test some

 * different settings on the loopback device. Normal chip configs

 * shall be STATIC and not altered by the driver!

 */

#include <linux/amba/pl022.h>



struct dummy {

	struct device *dev;

	struct mutex lock;

};



#define DMA_TEST_SIZE 2048



/* When we cat /sys/bus/spi/devices/spi0.0/looptest this will be triggered */

static ssize_t dummy_looptest(struct device *dev,

		struct device_attribute *attr, char *buf)

{

	struct spi_device *spi = to_spi_device(dev);

	struct dummy *p_dummy = dev_get_drvdata(&spi->dev);



	/*

	 * WARNING! Do not dereference the chip-specific data in any normal

	 * driver for a chip. It is usually STATIC and shall not be read

	 * or written to. Your chip driver should NOT depend on fields in this

	 * struct, this is just used here to alter the behaviour of the chip

	 * in order to perform tests.

	 */

	int status;

	u8 txbuf[14] = {0xDE, 0xAD, 0xBE, 0xEF, 0x2B, 0xAD,

			0xCA, 0xFE, 0xBA, 0xBE, 0xB1, 0x05,

			0xF0, 0x0D};

	u8 rxbuf[14];

	u8 *bigtxbuf_virtual;

	u8 *bigrxbuf_virtual;



	if (mutex_lock_interruptible(&p_dummy->lock))

		return -ERESTARTSYS;



	bigtxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL);

	if (bigtxbuf_virtual == NULL) {

		status = -ENOMEM;

		goto out;

	}

	bigrxbuf_virtual = kmalloc(DMA_TEST_SIZE, GFP_KERNEL);



	/* Fill TXBUF with some happy pattern */

	memset(bigtxbuf_virtual, 0xAA, DMA_TEST_SIZE);



	/*

	 * Force chip to 8 bit mode

	 * WARNING: NEVER DO THIS IN REAL DRIVER CODE, THIS SHOULD BE STATIC!

	 */

	spi->bits_per_word = 8;

	/* You should NOT DO THIS EITHER */

	spi->master->setup(spi);



	/* Now run the tests for 8bit mode */

	pr_info("Simple test 1: write 0xAA byte, read back garbage byte "

		"in 8bit mode\n");

	status = spi_w8r8(spi, 0xAA);

	if (status < 0)

		pr_warn("Simple test 1: FAILURE: spi_write_then_read failed with status %d\n",

			status);

	else

		pr_info("Simple test 1: SUCCESS!\n");



	pr_info("Simple test 2: write 8 bytes, read back 8 bytes garbage "

		"in 8bit mode (full FIFO)\n");

	status = spi_write_then_read(spi, &txbuf[0], 8, &rxbuf[0], 8);

	if (status < 0)

		pr_warn("Simple test 2: FAILURE: spi_write_then_read() failed with status %d\n",

			status);

	else

		pr_info("Simple test 2: SUCCESS!\n");



	pr_info("Simple test 3: write 14 bytes, read back 14 bytes garbage "

		"in 8bit mode (see if we overflow FIFO)\n");

	status = spi_write_then_read(spi, &txbuf[0], 14, &rxbuf[0], 14);

	if (status < 0)

		pr_warn("Simple test 3: FAILURE: failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 3: SUCCESS!\n");



	pr_info("Simple test 4: write 8 bytes with spi_write(), read 8 "

		"bytes garbage with spi_read() in 8bit mode\n");

	status = spi_write(spi, &txbuf[0], 8);

	if (status < 0)

		pr_warn("Simple test 4 step 1: FAILURE: spi_write() failed with status %d\n",

			status);

	else

		pr_info("Simple test 4 step 1: SUCCESS!\n");

	status = spi_read(spi, &rxbuf[0], 8);

	if (status < 0)

		pr_warn("Simple test 4 step 2: FAILURE: spi_read() failed with status %d\n",

			status);

	else

		pr_info("Simple test 4 step 2: SUCCESS!\n");



	pr_info("Simple test 5: write 14 bytes with spi_write(), read "

		"14 bytes garbage with spi_read() in 8bit mode\n");

	status = spi_write(spi, &txbuf[0], 14);

	if (status < 0)

		pr_warn("Simple test 5 step 1: FAILURE: spi_write() failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 5 step 1: SUCCESS!\n");

	status = spi_read(spi, &rxbuf[0], 14);

	if (status < 0)

		pr_warn("Simple test 5 step 2: FAILURE: spi_read() failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 5: SUCCESS!\n");



	pr_info("Simple test 6: write %d bytes with spi_write(), "

		"read %d bytes garbage with spi_read() in 8bit mode\n",

		DMA_TEST_SIZE, DMA_TEST_SIZE);

	status = spi_write(spi, &bigtxbuf_virtual[0], DMA_TEST_SIZE);

	if (status < 0)

		pr_warn("Simple test 6 step 1: FAILURE: spi_write() failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 6 step 1: SUCCESS!\n");

	status = spi_read(spi, &bigrxbuf_virtual[0], DMA_TEST_SIZE);

	if (status < 0)

		pr_warn("Simple test 6 step 2: FAILURE: spi_read() failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 6: SUCCESS!\n");





	/*

	 * Force chip to 16 bit mode

	 * WARNING: NEVER DO THIS IN REAL DRIVER CODE, THIS SHOULD BE STATIC!

	 */

	spi->bits_per_word = 16;

	/* You should NOT DO THIS EITHER */

	spi->master->setup(spi);



	pr_info("Simple test 7: write 0xAA byte, read back garbage byte "

		"in 16bit bus mode\n");

	status = spi_w8r8(spi, 0xAA);

	if (status == -EIO)

		pr_info("Simple test 7: SUCCESS! (expected failure with "

			"status EIO)\n");

	else if (status < 0)

		pr_warn("Simple test 7: FAILURE: spi_write_then_read failed with status %d\n",

			status);

	else

		pr_warn("Simple test 7: FAILURE: spi_write_then_read succeeded but it was expected to fail!\n");



	pr_info("Simple test 8: write 8 bytes, read back 8 bytes garbage "

		"in 16bit mode (full FIFO)\n");

	status = spi_write_then_read(spi, &txbuf[0], 8, &rxbuf[0], 8);

	if (status < 0)

		pr_warn("Simple test 8: FAILURE: spi_write_then_read() failed with status %d\n",

			status);

	else

		pr_info("Simple test 8: SUCCESS!\n");



	pr_info("Simple test 9: write 14 bytes, read back 14 bytes garbage "

		"in 16bit mode (see if we overflow FIFO)\n");

	status = spi_write_then_read(spi, &txbuf[0], 14, &rxbuf[0], 14);

	if (status < 0)

		pr_warn("Simple test 9: FAILURE: failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 9: SUCCESS!\n");



	pr_info("Simple test 10: write %d bytes with spi_write(), "

	       "read %d bytes garbage with spi_read() in 16bit mode\n",

	       DMA_TEST_SIZE, DMA_TEST_SIZE);

	status = spi_write(spi, &bigtxbuf_virtual[0], DMA_TEST_SIZE);

	if (status < 0)

		pr_warn("Simple test 10 step 1: FAILURE: spi_write() failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 10 step 1: SUCCESS!\n");



	status = spi_read(spi, &bigrxbuf_virtual[0], DMA_TEST_SIZE);

	if (status < 0)

		pr_warn("Simple test 10 step 2: FAILURE: spi_read() failed with status %d (probably FIFO overrun)\n",

			status);

	else

		pr_info("Simple test 10: SUCCESS!\n");



	status = sprintf(buf, "loop test complete\n");

	kfree(bigrxbuf_virtual);

	kfree(bigtxbuf_virtual);

 out:

	mutex_unlock(&p_dummy->lock);

	return status;

}



static DEVICE_ATTR(looptest, S_IRUGO, dummy_looptest, NULL);



static int pl022_dummy_probe(struct spi_device *spi)

{

	struct dummy *p_dummy;

	int status;



	dev_info(&spi->dev, "probing dummy SPI device\n");



	p_dummy = kzalloc(sizeof *p_dummy, GFP_KERNEL);

	if (!p_dummy)

		return -ENOMEM;



	dev_set_drvdata(&spi->dev, p_dummy);

	mutex_init(&p_dummy->lock);



	/* sysfs hook */

	status = device_create_file(&spi->dev, &dev_attr_looptest);

	if (status) {

		dev_dbg(&spi->dev, "device_create_file looptest failure.\n");

		goto out_dev_create_looptest_failed;

	}



	return 0;



out_dev_create_looptest_failed:

	dev_set_drvdata(&spi->dev, NULL);

	kfree(p_dummy);

	return status;

}



static int pl022_dummy_remove(struct spi_device *spi)

{

	struct dummy *p_dummy = dev_get_drvdata(&spi->dev);



	dev_info(&spi->dev, "removing dummy SPI device\n");

	device_remove_file(&spi->dev, &dev_attr_looptest);

	dev_set_drvdata(&spi->dev, NULL);

	kfree(p_dummy);



	return 0;

}



static const struct of_device_id pl022_dummy_dt_match[] = {

	{ .compatible = "arm,pl022-dummy" },

	{},

};



static struct spi_driver pl022_dummy_driver = {

	.driver = {

		.name	= "spi-dummy",

		.of_match_table = pl022_dummy_dt_match,

	},

	.probe	= pl022_dummy_probe,

	.remove	= pl022_dummy_remove,

};



module_spi_driver(pl022_dummy_driver);

MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");

MODULE_DESCRIPTION("PL022 SSP/SPI DUMMY Linux driver");

MODULE_LICENSE("GPL");

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