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ARM: 5667/3: U300 SSP/SPI board setup and test

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This adds a U300 board configuration for the PL022 SSP/SPI
PrimeCell driver recently merged to the 2.6.31-rc series.
Further it adds a dummy loopback SPI chip that can be used
for testing the SPI functionality on a running system using
the loopback mode of PL022.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This commit is contained in:
Linus Walleij 2009-08-14 10:59:05 +01:00 committed by Russell King
parent df1e0520f9
commit c7c8c78fdf
6 changed files with 460 additions and 0 deletions
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12
arch/arm/mach-u300/Kconfig
View file

@ -81,6 +81,18 @@ config MACH_U300_SEMI_IS_SHARED
Memory Interface) from both from access and application
side.
config MACH_U300_SPIDUMMY
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.
comment "All the settings below must match the bootloader's settings"
config MACH_U300_ACCESS_MEM_SIZE

2
arch/arm/mach-u300/Makefile
View file

@ -9,3 +9,5 @@ obj- :=
obj-$(CONFIG_ARCH_U300) += u300.o
obj-$(CONFIG_MMC) += mmc.o
obj-$(CONFIG_SPI_PL022) += spi.o
obj-$(CONFIG_MACH_U300_SPIDUMMY) += dummyspichip.o

6
arch/arm/mach-u300/core.c
View file

@ -32,6 +32,7 @@
#include "clock.h"
#include "mmc.h"
#include "spi.h"
/*
* Static I/O mappings that are needed for booting the U300 platforms. The
@ -611,6 +612,8 @@ void __init u300_init_devices(void)
/* Wait for the PLL208 to lock if not locked in yet */
while (!(readw(U300_SYSCON_VBASE + U300_SYSCON_CSR) &
U300_SYSCON_CSR_PLL208_LOCK_IND));
/* Initialize SPI device with some board specifics */
u300_spi_init(&pl022_device);
/* Register the AMBA devices in the AMBA bus abstraction layer */
u300_clock_primecells();
@ -622,6 +625,9 @@ void __init u300_init_devices(void)
u300_assign_physmem();
/* Register subdevices on the SPI bus */
u300_spi_register_board_devices();
/* Register the platform devices */
platform_add_devices(platform_devs, ARRAY_SIZE(platform_devs));

290
arch/arm/mach-u300/dummyspichip.c Normal file
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@ -0,0 +1,290 @@
/*
* 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>
/*
* 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");

124
arch/arm/mach-u300/spi.c Normal file
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@ -0,0 +1,124 @@
/*
* arch/arm/mach-u300/spi.c
*
* Copyright (C) 2009 ST-Ericsson AB
* License terms: GNU General Public License (GPL) version 2
*
* Author: Linus Walleij <linus.walleij@stericsson.com>
*/
#include <linux/device.h>
#include <linux/amba/bus.h>
#include <linux/spi/spi.h>
#include <linux/amba/pl022.h>
#include <linux/err.h>
#include "padmux.h"
/*
* The following is for the actual devices on the SSP/SPI bus
*/
#ifdef CONFIG_MACH_U300_SPIDUMMY
static void select_dummy_chip(u32 chipselect)
{
pr_debug("CORE: %s called with CS=0x%x (%s)\n",
__func__,
chipselect,
chipselect ? "unselect chip" : "select chip");
/*
* Here you would write the chip select value to the GPIO pins if
* this was a real chip (but this is a loopback dummy).
*/
}
struct pl022_config_chip dummy_chip_info = {
/* Nominally this is LOOPBACK_DISABLED, but this is our dummy chip! */
.lbm = LOOPBACK_ENABLED,
/*
* available POLLING_TRANSFER and INTERRUPT_TRANSFER,
* DMA_TRANSFER does not work
*/
.com_mode = INTERRUPT_TRANSFER,
.iface = SSP_INTERFACE_MOTOROLA_SPI,
/* We can only act as master but SSP_SLAVE is possible in theory */
.hierarchy = SSP_MASTER,
/* 0 = drive TX even as slave, 1 = do not drive TX as slave */
.slave_tx_disable = 0,
/* LSB first */
.endian_tx = SSP_TX_LSB,
.endian_rx = SSP_RX_LSB,
.data_size = SSP_DATA_BITS_8, /* used to be 12 in some default */
.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
.clk_phase = SSP_CLK_FALLING_EDGE,
.clk_pol = SSP_CLK_POL_IDLE_LOW,
.ctrl_len = SSP_BITS_12,
.wait_state = SSP_MWIRE_WAIT_ZERO,
.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
/*
* This is where you insert a call to a function to enable CS
* (usually GPIO) for a certain chip.
*/
.cs_control = select_dummy_chip,
};
#endif
static struct spi_board_info u300_spi_devices[] = {
#ifdef CONFIG_MACH_U300_SPIDUMMY
{
/* A dummy chip used for loopback tests */
.modalias = "spi-dummy",
/* Really dummy, pass in additional chip config here */
.platform_data = NULL,
/* This defines how the controller shall handle the device */
.controller_data = &dummy_chip_info,
/* .irq - no external IRQ routed from this device */
.max_speed_hz = 1000000,
.bus_num = 0, /* Only one bus on this chip */
.chip_select = 0,
/* Means SPI_CS_HIGH, change if e.g low CS */
.mode = 0,
},
#endif
};
static struct pl022_ssp_controller ssp_platform_data = {
/* If you have several SPI buses this varies, we have only bus 0 */
.bus_id = 0,
/* Set this to 1 when we think we got DMA working */
.enable_dma = 0,
/*
* On the APP CPU GPIO 4, 5 and 6 are connected as generic
* chip selects for SPI. (Same on U330, U335 and U365.)
* TODO: make sure the GPIO driver can select these properly
* and do padmuxing accordingly too.
*/
.num_chipselect = 3,
};
void __init u300_spi_init(struct amba_device *adev)
{
struct pmx *pmx;
adev->dev.platform_data = &ssp_platform_data;
/*
* Setup padmuxing for SPI. Since this must always be
* compiled into the kernel, pmx is never released.
*/
pmx = pmx_get(&adev->dev, U300_APP_PMX_SPI_SETTING);
if (IS_ERR(pmx))
dev_warn(&adev->dev, "Could not get padmux handle\n");
else {
int ret;
ret = pmx_activate(&adev->dev, pmx);
if (IS_ERR_VALUE(ret))
dev_warn(&adev->dev, "Could not activate padmuxing\n");
}
}
void __init u300_spi_register_board_devices(void)
{
/* Register any SPI devices */
spi_register_board_info(u300_spi_devices, ARRAY_SIZE(u300_spi_devices));
}

26
arch/arm/mach-u300/spi.h Normal file
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@ -0,0 +1,26 @@
/*
* arch/arm/mach-u300/spi.h
*
* Copyright (C) 2009 ST-Ericsson AB
* License terms: GNU General Public License (GPL) version 2
*
* Author: Linus Walleij <linus.walleij@stericsson.com>
*/
#ifndef SPI_H
#define SPI_H
#include <linux/amba/bus.h>
#ifdef CONFIG_SPI_PL022
void __init u300_spi_init(struct amba_device *adev);
void __init u300_spi_register_board_devices(void);
#else
/* Compile out SPI support if PL022 is not selected */
static inline void __init u300_spi_init(struct amba_device *adev)
{
}
static inline void __init u300_spi_register_board_devices(void)
{
}
#endif
#endif