| /* | 
 |  * 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. | 
 | 	 */ | 
 | 	struct pl022_config_chip *chip_info = spi->controller_data; | 
 | 	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! | 
 | 	 */ | 
 | 	chip_info->data_size = SSP_DATA_BITS_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! | 
 | 	 */ | 
 | 	chip_info->data_size = SSP_DATA_BITS_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"); |