From: Oleksij Rempel <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>
This is simple interface to talk over SSI32 bus.
For testing fallwoing commands can be used:
while true; do cat /dev/iccch015 | hexdump; done &
while true; do echo 1 > /dev/iccch015; done
Signed-off-by: Oleksij Rempel <linux@xxxxxxxxxxxxxxxx>
Signed-off-by: Oleksij Rempel <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>
---
drivers/char/Kconfig | 9 ++
drivers/char/Makefile | 1 +
drivers/char/icc_char.c | 280 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 290 insertions(+)
create mode 100644 drivers/char/icc_char.c
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index a4af822..e610173 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -611,5 +611,14 @@ config TILE_SROM
source "drivers/char/xillybus/Kconfig"
+config ICC_CHAR
+ tristate "ICC char interface"
+ depends on ICC
+ default y
+ help
+ If you say yes here you get char device communication over
+ ICC bus.
+
+
endmenu
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index d06cde26..0439daa 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -62,3 +62,4 @@ js-rtc-y = rtc.o
obj-$(CONFIG_TILE_SROM) += tile-srom.o
obj-$(CONFIG_XILLYBUS) += xillybus/
+obj-$(CONFIG_ICC_CHAR) += icc_char.o
diff --git a/drivers/char/icc_char.c b/drivers/char/icc_char.c
new file mode 100644
index 0000000..a4005c7
--- /dev/null
+++ b/drivers/char/icc_char.c
@@ -0,0 +1,280 @@
+/*
+ * Char device for ICC bus.
+ *
+ * Copyright (C) Robert Bosch Car Multimedia GmbH
+ * Authors:
+ * Oleksij Rempel
+ * <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>
+ * <linux@xxxxxxxxxxxxxxxx>
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/cdev.h>
+#include <linux/fs.h>
+#include <linux/icc/icc.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/proc_fs.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+#include <asm/uaccess.h>
+
+static unsigned int icc_ch_major;
+
+struct icc_ch_priv {
+ struct device *dev;
+ struct icc_device *iccd;
+ struct cdev cdev;
+
+
+ struct icc_trf trf;
+ void *rx_buf;
+ size_t rx_buf_size;
+ struct mutex rx_buf_lock;
+ wait_queue_head_t rx_wq;
+};
+
+static int icc_ch_int_trf(struct icc_ch_priv *priv)
+{
+ struct icc_device *iccd = priv->iccd;
+ struct icc_master *iccm = iccd->iccm;
+ struct icc_trf *trf = &priv->trf;
+ int ret;
+
+ ret = icc_trf_alloc(iccm, trf, iccd->lun_number,
+ iccm->max_data_size);
+ if (ret)
+ return ret;
+
+ priv->rx_buf = devm_kzalloc(priv->dev, iccm->max_data_size,
+ GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static ssize_t icc_ch_fop_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *pos)
+{
+ struct icc_ch_priv *priv = file->private_data;
+ struct icc_device *iccd = priv->iccd;
+ struct icc_master *iccm = iccd->iccm;
+ int ret;
+
+ if (count > iccm->max_data_size)
+ return -EINVAL;
+
+ count = min(count, (size_t)iccm->max_data_size);
+ if (copy_from_user(priv->trf.data, buf, count))
+ return -EFAULT;
+
+ priv->trf.data_size = count;
+
+ ret = icc_trf_xmit(iccm, &priv->trf);
+ if (ret)
+ return ret;
+
+ return count;
+}
+
+static int icc_ch_wait(struct icc_ch_priv *priv) {
+ return wait_event_interruptible(priv->rx_wq, priv->rx_buf_size);
+}
+
+static void icc_ch_wake(struct icc_ch_priv *priv) {
+ wake_up_interruptible(&priv->rx_wq);
+}
+
+static ssize_t icc_ch_fop_read(struct file *file, char *buf,
+ size_t count, loff_t *ppos)
+{
+ struct icc_ch_priv *priv = file->private_data;
+ size_t ret = 0;
+
+ if (*ppos != 0)
+ return 0;
+
+ ret = icc_ch_wait(priv);
+ if (ret)
+ return ret;
+
+ mutex_lock(&priv->rx_buf_lock);
+
+ if (!priv->rx_buf_size) {
+ ret = 0;
+ goto done;
+ }
+
+ if (count < priv->rx_buf_size) {
+ ret = -EINVAL;
+ goto done;
+ }
+
+ if (copy_to_user(buf, priv->rx_buf, priv->rx_buf_size)) {
+ ret = -EINVAL;
+ goto done;
+ }
+
+ ret = *ppos = priv->rx_buf_size;
+ priv->rx_buf_size = 0;
+
+ mutex_unlock(&priv->rx_buf_lock);
+
+done:
+ return ret;
+}
+
+static int icc_ch_fop_open(struct inode *ino, struct file *file)
+{
+ file->private_data =
+ container_of(ino->i_cdev, struct icc_ch_priv, cdev);
+
+ return 0;
+}
+
+static const struct file_operations icc_ch_fops = {
+ .owner = THIS_MODULE,
+ .open = icc_ch_fop_open,
+ .read = icc_ch_fop_read,
+ .write = icc_ch_fop_write,
+};
+
+static int icc_ch_rx_cb(struct icc_device *iccd, void *rx_buf, size_t size)
+{
+ struct icc_ch_priv *priv = icc_get_drvdata(iccd);
+
+ /*
+ * if we can't transfer it no, drop it
+ * allow other do the job
+ */
+ if (!mutex_trylock(&priv->rx_buf_lock))
+ return -EBUSY;
+
+ /*
+ * TODO: we should decide what kind of logic do we use.
+ * For example for GPS it would make no match sense to
+ * keep old and not valid data.
+ * For now, let's be save and keep it.
+ */
+ if (priv->rx_buf_size) {
+ mutex_unlock(&priv->rx_buf_lock);
+ return -EBUSY;
+ }
+
+ memcpy(priv->rx_buf, rx_buf, size);
+ priv->rx_buf_size = size;
+
+ mutex_unlock(&priv->rx_buf_lock);
+ icc_ch_wake(priv);
+
+ return 0;
+}
+
+static int icc_ch_probe(struct icc_device *iccd)
+{
+ struct icc_master *iccm = iccd->iccm;
+ struct device *dev = &iccd->dev;
+ struct device *dev1;
+ struct icc_ch_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(struct icc_ch_priv),
+ GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->dev = dev;
+ priv->iccd = iccd;
+ mutex_init(&priv->rx_buf_lock);
+ init_waitqueue_head(&priv->rx_wq);
+
+ icc_set_drvdata(iccd, priv);
+ icc_set_rxcb(iccd, icc_ch_rx_cb);
+
+ ret = icc_ch_int_trf(priv);
+ if (ret)
+ return ret;
+
+ cdev_init(&priv->cdev, &icc_ch_fops);
+ priv->cdev.owner = THIS_MODULE;
+ ret = cdev_add(&priv->cdev, MKDEV(icc_ch_major, iccd->lun_number), 1);
+ if (ret) {
+ dev_err(dev, "filed to add cdev\n");
+ return ret;
+ }
+
+ dev1 = device_create(iccm->icc_class, dev,
+ MKDEV(icc_ch_major, iccd->lun_number),
+ priv, "iccch%03d", iccd->lun_number);
+
+ if (IS_ERR(dev1)) {
+ dev_info(dev, "ICC chardev filed: %i\n", PTR_ERR(dev1));
+ return PTR_ERR(dev1);
+ }
+
+ dev_info(dev, "ICC chardev enabled\n");
+ return 0;
+}
+
+static int icc_ch_remove(struct icc_device *iccd)
+{
+ struct icc_master *iccm = iccd->iccm;
+
+ device_destroy(iccm->icc_class,
+ MKDEV(icc_ch_major, iccd->lun_number));
+ return 0;
+}
+
+static const struct of_device_id icc_ch_of_match[] = {
+ { .compatible = "rbcm,ssi32-char-v1" },
+ { .compatible = "rbcm,icc-char-v1" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, icc_ch_of_match);
+
+static struct icc_driver icc_ch_driver = {
+ .driver = {
+ .name = "icc-ch",
+ .owner = THIS_MODULE,
+ .of_match_table = icc_ch_of_match,
+ },
+ .probe = icc_ch_probe,
+ .remove = icc_ch_remove,
+};
+
+static int __init icc_ch_init(void)
+{
+ static dev_t dev;
+ int ret;
+
+ ret = alloc_chrdev_region(&dev, 0, ICC_MAX_LUNS, "iccch");
+ if (ret)
+ pr_err("Unable to register ICC chdev region\n");
+
+ icc_ch_major = MAJOR(dev);
+
+ ret = icc_register_driver(&icc_ch_driver);
+ if (ret)
+ pr_err("Unable to register ICC chdev\n");
+
+ return ret;
+}
+
+module_init(icc_ch_init);
+
+static void __exit
+icc_ch_exit(void)
+{
+ icc_unregister_driver(&icc_ch_driver);
+ unregister_chrdev_region(MKDEV(icc_ch_major, 0), ICC_MAX_LUNS);
+}
+
+module_exit(icc_ch_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Oleksij Rempel <fixed-term.Oleksij.Rempel@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("ICC chardev");
--
1.9.1
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