arch/arm/mach-u300/dummyspichip.c - kernel/bruno - Git at Google

 /*
  * 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_warning("Siple 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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("Siple test 7: FAILURE: spi_write_then_read "
 			   "failed with status %d\n", status);
 	else
 		pr_warning("Siple 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_warning("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_warning("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_warning("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_warning("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 __devinit 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 __devexit 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 struct spi_driver pl022_dummy_driver = {
 	.driver = {
 		.name	= "spi-dummy",
 		.owner	= THIS_MODULE,
 	},
 	.probe	= pl022_dummy_probe,
 	.remove	= __devexit_p(pl022_dummy_remove),
 };

 static int __init pl022_init_dummy(void)
 {
 	return spi_register_driver(&pl022_dummy_driver);
 }

 static void __exit pl022_exit_dummy(void)
 {
 	spi_unregister_driver(&pl022_dummy_driver);
 }

 module_init(pl022_init_dummy);
 module_exit(pl022_exit_dummy);

 MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
 MODULE_DESCRIPTION("PL022 SSP/SPI DUMMY Linux driver");
 MODULE_LICENSE("GPL");
	/*
	* 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_warning("Siple 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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("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_warning("Siple test 7: FAILURE: spi_write_then_read "
	"failed with status %d\n", status);
	else
	pr_warning("Siple 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_warning("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_warning("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_warning("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_warning("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 __devinit 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 __devexit 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 struct spi_driver pl022_dummy_driver = {
	.driver = {
	.name = "spi-dummy",
	.owner = THIS_MODULE,
	},
	.probe = pl022_dummy_probe,
	.remove = __devexit_p(pl022_dummy_remove),
	};

	static int __init pl022_init_dummy(void)
	{
	return spi_register_driver(&pl022_dummy_driver);
	}

	static void __exit pl022_exit_dummy(void)
	{
	spi_unregister_driver(&pl022_dummy_driver);
	}

	module_init(pl022_init_dummy);
	module_exit(pl022_exit_dummy);

	MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
	MODULE_DESCRIPTION("PL022 SSP/SPI DUMMY Linux driver");
	MODULE_LICENSE("GPL");