This testdriver can be used to test flow control
functionality by using some gpio pins to emulate
slave device.
Signed-off-by: Oleksij Rempel <linux@xxxxxxxxxxxxxxxx>
---
drivers/spi/Kconfig | 12 ++
drivers/spi/Makefile | 1 +
drivers/spi/spi_fc_test.c | 273 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 286 insertions(+)
create mode 100644 drivers/spi/spi_fc_test.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7706416..fb96295 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -681,6 +681,18 @@ config SPI_DW_MMIO
#
comment "SPI Protocol Masters"
+config SPI_FC_TEST
+ tristate "Test for SPI flow control functionality"
+ depends on SPI
+ default n
+ help
+ This option enables test module for flow control SPI
+ extensions. For testing use debugfs interface with count
+ of packet wich should be used for testing. For example:
+ echo 100000 > /sys/kernel/debug/spi_fc_test/spi0/test_fc_request
+
+ If unsure, say N.
+
config SPI_SPIDEV
tristate "User mode SPI device driver support"
help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 8991ffc..282224a 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -37,6 +37,7 @@ spi-dw-midpci-objs := spi-dw-pci.o spi-dw-mid.o
obj-$(CONFIG_SPI_EFM32) += spi-efm32.o
obj-$(CONFIG_SPI_EP93XX) += spi-ep93xx.o
obj-$(CONFIG_SPI_FALCON) += spi-falcon.o
+obj-$(CONFIG_SPI_FC_TEST) += spi_fc_test.o
obj-$(CONFIG_SPI_FSL_CPM) += spi-fsl-cpm.o
obj-$(CONFIG_SPI_FSL_DSPI) += spi-fsl-dspi.o
obj-$(CONFIG_SPI_FSL_LIB) += spi-fsl-lib.o
diff --git a/drivers/spi/spi_fc_test.c b/drivers/spi/spi_fc_test.c
new file mode 100644
index 0000000..65bff99
--- /dev/null
+++ b/drivers/spi/spi_fc_test.c
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) Robert Bosch Car Multimedia GmbH
+ * Copyright (C) Oleksij Rempel <linux@xxxxxxxxxxxxxxxx>
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/proc_fs.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+#define DRIVER_NAME "spi_fc_test"
+
+static struct dentry *debugfs_root;
+/*
+ * Some registers must be read back to modify.
+ * To save time we cache them here in memory
+ */
+struct spi_fc_test_priv {
+ struct mutex lock; /* protect from simultaneous accesses */
+ u8 port_config;
+ struct spi_device *spi;
+ struct gpio_desc *test_cs_in;
+ struct gpio_desc *test_fc_out;
+ struct dentry *debugfs;
+ struct completion fc_complete;
+ atomic_t active_rq;
+};
+
+static int spi_fc_test_set(struct spi_fc_test_priv *priv)
+{
+ u8 buf;
+
+ buf = 0xaa;
+ return spi_write(priv->spi, &buf, sizeof(buf));
+}
+
+static void spi_fc_test_request_cb(struct spi_device *spi)
+{
+ struct spi_fc_test_priv *priv = spi_get_drvdata(spi);
+
+ complete(&priv->fc_complete);
+}
+
+static ssize_t spi_fc_fops_request_write(struct file *file, const char
+ __user *user_buf, size_t count, loff_t *data)
+{
+ struct spi_fc_test_priv *priv = file_inode(file)->i_private ?:
+ PDE_DATA(file_inode(file));
+ unsigned long timeout = msecs_to_jiffies(10);
+ u32 rounds;
+ int ret;
+
+ if (kstrtouint_from_user(user_buf, count, 0, &rounds))
+ return -EINVAL;
+
+ mutex_lock(&priv->lock);
+ while (rounds > 0) {
+ atomic_set(&priv->active_rq, 1);
+ reinit_completion(&priv->fc_complete);
+ gpiod_set_value(priv->test_fc_out, true);
+ ret = wait_for_completion_io_timeout(&priv->fc_complete,
+ timeout);
+ if (!ret) {
+ dev_err(&priv->spi->dev, "Request timeout\n");
+ goto exit;
+ }
+ ret = spi_fc_test_set(priv);
+ if (ret < 0) {
+ dev_err(&priv->spi->dev, "SPI transfer error\n");
+ goto exit;
+ }
+ rounds--;
+ }
+exit:
+ gpiod_set_value(priv->test_fc_out, false);
+ mutex_unlock(&priv->lock);
+ return count;
+}
+
+const struct file_operations spi_fc_fops_request = {
+ .owner = THIS_MODULE,
+ .write = spi_fc_fops_request_write,
+};
+
+static ssize_t spi_fc_fops_ready_write(struct file *file, const char
+ __user *user_buf, size_t count, loff_t *data)
+{
+ struct spi_fc_test_priv *priv = file_inode(file)->i_private ?:
+ PDE_DATA(file_inode(file));
+ u32 rounds;
+ int ret;
+
+ if (kstrtouint_from_user(user_buf, count, 0, &rounds))
+ return -EINVAL;
+
+ mutex_lock(&priv->lock);
+ while (rounds > 0) {
+ ret = spi_fc_test_set(priv);
+ if (ret < 0) {
+ mutex_unlock(&priv->lock);
+ return ret;
+ }
+ rounds--;
+ }
+ mutex_unlock(&priv->lock);
+
+ return count;
+}
+
+const struct file_operations spi_fc_fops_ready = {
+ .owner = THIS_MODULE,
+ .write = spi_fc_fops_ready_write,
+};
+
+static irqreturn_t spi_fc_test_isr(int irq, void *dev_id)
+{
+ struct spi_fc_test_priv *priv = (struct spi_fc_test_priv *)dev_id;
+ int val;
+
+ if (atomic_read(&priv->active_rq)) {
+ atomic_set(&priv->active_rq, 0);
+ return IRQ_HANDLED;
+ }
+
+ val = gpiod_get_value(priv->test_cs_in);
+ gpiod_set_value(priv->test_fc_out, val);
+
+ return IRQ_HANDLED;
+}
+
+static int spi_fc_test_probe(struct spi_device *spi)
+{
+ struct spi_fc_test_priv *priv;
+ struct dentry *de;
+ int ret, cs_irq;
+
+ spi->bits_per_word = 8;
+
+ ret = spi_setup(spi);
+ if (ret < 0)
+ return ret;
+
+ priv = devm_kzalloc(&spi->dev, sizeof(struct spi_fc_test_priv),
+ GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ mutex_init(&priv->lock);
+ init_completion(&priv->fc_complete);
+
+ spi_set_drvdata(spi, priv);
+
+ priv->spi = spi;
+ spi->master->rt = 1;
+ spi->request_cb = spi_fc_test_request_cb;
+
+ ret = spi_fc_probe(spi);
+ if (ret) {
+ dev_err(&spi->dev, "filed to probe FC\n");
+ return ret;
+ }
+
+ priv->test_fc_out = devm_gpiod_get(&spi->dev, "test-fc-out",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(priv->test_fc_out)) {
+ ret = PTR_ERR(priv->test_fc_out);
+ dev_err(&spi->dev, "failed to request FC GPIO: %d\n", ret);
+ return ret;
+ }
+
+ priv->test_cs_in = devm_gpiod_get(&spi->dev, "test-cs-in", GPIOD_IN);
+ if (IS_ERR(priv->test_cs_in)) {
+ ret = PTR_ERR(priv->test_cs_in);
+ dev_err(&spi->dev, "failed to request CS GPIO: %d\n", ret);
+ return ret;
+ }
+
+ cs_irq = gpiod_to_irq(priv->test_cs_in);
+ if (cs_irq < 0) {
+ dev_err(&spi->dev, "failed to reques irq for GPIO\n");
+ return -ENODEV;
+ }
+
+ ret = devm_request_irq(&spi->dev, cs_irq, spi_fc_test_isr,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ "test_cs_in", priv);
+ if (ret) {
+ dev_err(&spi->dev, "failed to request IRQ\n");
+ return ret;
+ }
+
+ priv->debugfs = debugfs_create_dir(dev_name(&spi->dev), debugfs_root);
+ de = debugfs_create_file_size("test_fc_ready", S_IRUGO,
+ priv->debugfs, priv, &spi_fc_fops_ready,
+ sizeof(u32));
+ if (IS_ERR_OR_NULL(de)) {
+ dev_err(&spi->dev, "failed to create test_fc_ready\n");
+ return -ENODEV;
+ }
+
+ de = debugfs_create_file_size("test_fc_request", S_IRUGO,
+ priv->debugfs, priv, &spi_fc_fops_request,
+ sizeof(u32));
+ if (IS_ERR_OR_NULL(de)) {
+ dev_err(&spi->dev, "failed to create test_fc_request\n");
+ return -ENODEV;
+ }
+
+ return ret;
+}
+
+static int spi_fc_test_remove(struct spi_device *spi)
+{
+ struct spi_fc_test_priv *priv;
+
+ priv = spi_get_drvdata(spi);
+ if (!priv)
+ return -ENODEV;
+
+ mutex_destroy(&priv->lock);
+
+ return 0;
+}
+
+static const struct of_device_id spi_fc_test_gpio_match[] = {
+ {
+ .compatible = "spi-fc-test",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, spi_fc_test_gpio_match);
+
+static struct spi_driver spi_fc_test_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = of_match_ptr(spi_fc_test_gpio_match),
+ },
+ .probe = spi_fc_test_probe,
+ .remove = spi_fc_test_remove,
+};
+
+static int __init spi_fc_test_init(void)
+{
+ debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
+ if (IS_ERR_OR_NULL(debugfs_root)) {
+ pr_err("%s: Filed to create debufs entry.\n", DRIVER_NAME);
+ return -ENOMEM;
+ }
+
+ return spi_register_driver(&spi_fc_test_driver);
+}
+subsys_initcall(spi_fc_test_init);
+
+static void __exit spi_fc_test_exit(void)
+{
+ debugfs_remove_recursive(debugfs_root);
+ spi_unregister_driver(&spi_fc_test_driver);
+}
+module_exit(spi_fc_test_exit);
+
+MODULE_AUTHOR("Oleksij Rempel <linux@xxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");
+
--
1.9.1
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