[alsa-devel] [PATCH 2/3] ECI: introducing ECI bus driver
tapio.vihuri at nokia.com
tapio.vihuri at nokia.com
Wed Dec 22 13:20:34 CET 2010
From: Tapio Vihuri <tapio.vihuri at nokia.com>
ECI bus controller is kind of bridge between host CPU I2C and ECI accessory
ECI communication.
Signed-off-by: Tapio Vihuri <tapio.vihuri at nokia.com>
---
drivers/Kconfig | 2 +
drivers/Makefile | 1 +
drivers/ecibus/Kconfig | 46 ++++
drivers/ecibus/Makefile | 10 +
drivers/ecibus/ecibus.c | 583 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/input/eci.h | 8 +
6 files changed, 650 insertions(+), 0 deletions(-)
create mode 100644 drivers/ecibus/Kconfig
create mode 100644 drivers/ecibus/Makefile
create mode 100644 drivers/ecibus/ecibus.c
diff --git a/drivers/Kconfig b/drivers/Kconfig
index a2b902f..f450f98 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -111,4 +111,6 @@ source "drivers/xen/Kconfig"
source "drivers/staging/Kconfig"
source "drivers/platform/Kconfig"
+
+source "drivers/ecibus/Kconfig"
endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index f3ebb30..11f5d57 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -113,5 +113,6 @@ obj-$(CONFIG_SSB) += ssb/
obj-$(CONFIG_VHOST_NET) += vhost/
obj-$(CONFIG_VLYNQ) += vlynq/
obj-$(CONFIG_STAGING) += staging/
+obj-$(CONFIG_ECI) += ecibus/
obj-y += platform/
obj-y += ieee802154/
diff --git a/drivers/ecibus/Kconfig b/drivers/ecibus/Kconfig
new file mode 100644
index 0000000..27e5e36
--- /dev/null
+++ b/drivers/ecibus/Kconfig
@@ -0,0 +1,46 @@
+#
+# ECI driver configuration
+#
+menuconfig ECI
+ bool "ECI support"
+ help
+ ECI (Enhancement Control Interface) accessory support
+
+ The Enhancement Control Interface functionality
+ ECI is better known as Multimedia Headset for Nokia phones.
+ If headset has many buttons, like play, vol+, vol- etc. then
+ it is propably ECI accessory.
+ Among several buttons ECI accessory contains memory for storing
+ several parameters.
+
+ Enable ECI support in terminal so that ECI input driver is able
+ to communicate with ECI accessory
+
+if ECI
+
+config ECI_DEBUG
+ boolean "Debug support for ECI drivers"
+ depends on DEBUG_KERNEL
+ help
+ Selects ECI driver debug messaging.
+
+ Say "yes" to enable debug messaging (like dev_dbg and pr_debug),
+ sysfs, and debugfs support in ECI controller.
+
+comment "ECI Master Controller Drivers"
+
+config ECI_BUS
+ tristate "ECI bus controller driver"
+ select INPUT_ECI
+ help
+ This selects a driver for the ECI bus controller
+
+ ECI bus controller is kind of bridge between host CPU I2C and
+ ECI accessory ECI communication.
+
+ Say 'y' here to statically link this module into the kernel or 'm'
+ to build it as a dynamically loadable module. The module will be
+ called ecibus.ko
+
+
+endif # ECI
diff --git a/drivers/ecibus/Makefile b/drivers/ecibus/Makefile
new file mode 100644
index 0000000..ce4206b
--- /dev/null
+++ b/drivers/ecibus/Makefile
@@ -0,0 +1,10 @@
+#
+# Makefile for kernel ECI drivers.
+#
+
+ifeq ($(CONFIG_ECI_DEBUG),y)
+EXTRA_CFLAGS += -DDEBUG
+endif
+
+# ECI master controller drivers (bus)
+obj-$(CONFIG_ECI_BUS) += ecibus.o
diff --git a/drivers/ecibus/ecibus.c b/drivers/ecibus/ecibus.c
new file mode 100644
index 0000000..93266b3
--- /dev/null
+++ b/drivers/ecibus/ecibus.c
@@ -0,0 +1,583 @@
+/*
+ * This file is part of ECI (Enhancement Control Interface) bus controller
+ * driver
+ *
+ * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+ *
+ * Contact: Tapio Vihuri <tapio.vihuri at nokia.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ */
+
+/*
+ * ECI stands for (Enhancement Control Interface).
+ *
+ * ECI is better known as Multimedia Headset for Nokia phones.
+ * If headset has many buttons, like play, vol+, vol- etc. then it is propably
+ * ECI accessory.
+ *
+ * ECI bus controller is kind of bridge between host CPU I2C and ECI accessory
+ * ECI communication.
+ */
+
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/debugfs.h>
+#include <linux/input/eci.h>
+
+#include <asm/intel_scu_ipc.h>
+
+/*
+ * VPROG2CNT - VPROG2 Control Register
+ * 2.5V | normal | normal
+ * 10 | 111 | 111
+ * 2.5V | off | off
+ * 10 | 100 | 100
+ */
+#define AvP_MSIC_VPROG2 0xd7
+#define AvP_MSIC_VPROG2_2V5_ON 0xbf
+#define AvP_MSIC_VPROG2_2V5_OFF 0xa4
+
+#define ECIBUS_I2C_ADDRS 0x6d
+#define ECIBUS_STATUS_DATA_READY 0x01
+#define ECIBUS_STATUS_ACCESSORY_INT 0x02
+
+#define ECIBUS_WAIT_IRQ 100 /* msec */
+#define ECI_RST_MIN 62
+#define ECI_RST_WAIT 10 /* msec */
+
+struct ecibus_data {
+ struct i2c_client *client;
+ struct device *dev;
+ struct eci_cb *eci_callback;
+ int ecibus_rst_gpio;
+ int ecibus_sw_ctrl_gpio;
+ int ecibus_int_gpio;
+ wait_queue_head_t wait;
+ bool wait_eci_buttons;
+ bool wait_data;
+};
+
+static struct ecibus_data *the_ed;
+
+#ifdef CONFIG_DEBUG_FS
+static int ecibus_ctrl_read_reg(u8 reg);
+static int ecibus_ctrl_write_reg(u8 reg, u8 param);
+
+static struct dentry *ecibus_debugfs_dir;
+
+static ssize_t debug_read(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buf[80];
+ int len = 0;
+ int ret;
+
+ if (*ppos == 0) {
+ ret = ecibus_ctrl_read_reg(ECIREG_TEST_IN);
+ if (ret < 0)
+ return ret;
+ len += snprintf(buf + len, sizeof(buf) - len, "%02x\n", ret);
+ }
+
+ ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+
+ return ret;
+}
+
+static ssize_t debug_write(struct file *file, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ char buf[80];
+ int buf_size;
+ unsigned long val;
+
+ buf_size = min(count, (sizeof(buf)-1));
+ if (copy_from_user(buf, user_buf, buf_size))
+ return -EFAULT;
+
+ buf[buf_size] = '\0';
+ if (!strict_strtoul(buf, 0, &val))
+ ecibus_ctrl_write_reg(ECIREG_TEST_OUT, val);
+ else
+ return -EINVAL;
+
+ return count;
+}
+
+static ssize_t reset_read(struct file *file, char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct ecibus_data *ed = file->private_data;
+ char buf[80];
+ int len = 0;
+ int ret;
+
+ if (*ppos == 0) {
+ ret = !!gpio_get_value(ed->ecibus_rst_gpio);
+ len = snprintf(buf, sizeof(buf), "%d\n", ret);
+ }
+ ret = simple_read_from_buffer(user_buf, count, ppos, buf, len);
+
+ return ret;
+}
+
+static ssize_t reset_write(struct file *file, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ /* Assosiated in default_open() */
+ struct ecibus_data *ed = file->private_data;
+ char buf[32];
+ int buf_size;
+
+ buf_size = min(count, (sizeof(buf)-1));
+ if (copy_from_user(buf, user_buf, buf_size))
+ return -EFAULT;
+
+ if (!memcmp(buf, "0", 1))
+ gpio_set_value(ed->ecibus_rst_gpio, 0);
+ else if (!memcmp(buf, "1", 1))
+ gpio_set_value(ed->ecibus_rst_gpio, 1);
+
+ return count;
+}
+
+static int default_open(struct inode *inode, struct file *file)
+{
+ /* Assosiated in debugfs_create_file() */
+ if (inode->i_private)
+ file->private_data = inode->i_private;
+
+ return 0;
+}
+
+static const struct file_operations debug_fops = {
+ .open = default_open,
+ .read = debug_read,
+ .write = debug_write,
+};
+
+static const struct file_operations reset_fops = {
+ .open = default_open,
+ .read = reset_read,
+ .write = reset_write,
+};
+
+static void ecibus_uninitialize_debugfs(void)
+{
+ if (ecibus_debugfs_dir)
+ debugfs_remove_recursive(ecibus_debugfs_dir);
+}
+
+static long ecibus_initialize_debugfs(struct ecibus_data *ed)
+{
+ void *ok;
+
+ /* /sys/kernel/debug/ecibus.# */
+ ecibus_debugfs_dir = debugfs_create_dir(dev_name(ed->dev), NULL);
+ if (!ecibus_debugfs_dir)
+ return -ENOENT;
+
+ /* Struct ed assosiated to inode->i_private */
+ ok = debugfs_create_file("debug", S_IRUGO | S_IWUSR,
+ ecibus_debugfs_dir, ed, &debug_fops);
+ if (!ok)
+ goto fail;
+
+ ok = debugfs_create_file("reset", S_IRUGO | S_IWUSR,
+ ecibus_debugfs_dir, ed, &reset_fops);
+ if (!ok)
+ goto fail;
+
+ return 0;
+fail:
+ ecibus_uninitialize_debugfs();
+ return -ENOENT;
+}
+#else
+#define ecibus_initialize_debugfs(ed) 1
+#define ecibus_uninitialize_debugfs()
+#endif
+
+static struct i2c_board_info ecibus_i2c = {
+ I2C_BOARD_INFO("ecibus", ECIBUS_I2C_ADDRS) };
+
+/* For ecibus controller internal registers */
+static int ecibus_ctrl_read_reg(u8 reg)
+{
+
+ if (reg <= ECICMD_RESERVED)
+ return -EINVAL;
+
+ return i2c_smbus_read_byte_data(the_ed->client, reg);
+}
+
+static int ecibus_ctrl_write_reg(u8 reg, u8 param)
+{
+
+ if (reg <= ECICMD_RESERVED)
+ return -EINVAL;
+
+ return i2c_smbus_write_byte_data(the_ed->client, reg, param);
+}
+
+/* Reset and learn ECI accessory, ie. get speed */
+static int ecibus_acc_reset(void)
+{
+ s32 ret;
+
+ ecibus_ctrl_write_reg(ECIREG_RST_LEARN, 0);
+
+ msleep(ECI_RST_WAIT);
+
+ ret = ecibus_ctrl_read_reg(ECIREG_RST_LEARN);
+ if (ret < ECI_RST_MIN)
+ return -EIO;
+
+ return 0;
+}
+/* Read always four bytes, as stated in ECI specification */
+static int ecibus_acc_read_direct(u8 addr, char *buf)
+{
+ s32 ret;
+ int i;
+
+ /* Initiate ECI accessory memory read */
+ the_ed->wait_data = false;
+ if (!ecibus_ctrl_write_reg(ECIREG_READ_COUNT, 4))
+ if (ecibus_ctrl_write_reg(ECIREG_READ_DIRECT, addr))
+ return -EIO;
+
+ if (!wait_event_timeout(the_ed->wait, the_ed->wait_data == true,
+ msecs_to_jiffies(ECIBUS_WAIT_IRQ)))
+ return -EIO;
+
+ for (i = 0; i < 4; i++) {
+ ret = ecibus_ctrl_read_reg(ECIREG_READ_DIRECT + i);
+ if (ret < 0)
+ return ret;
+ buf[i] = ret;
+ usleep_range(2000, 10000);
+ }
+ return 0;
+}
+
+/* Trigger ECI accessory register data write (from accessory) */
+static int ecibus_fire_acc_read_reg(u8 reg, int count)
+{
+ if (!ecibus_ctrl_write_reg(ECIREG_READ_COUNT, count))
+ return i2c_smbus_read_byte_data(the_ed->client, reg);
+ else
+ return -EIO;
+}
+
+/* For ECI accessory internal registers */
+static int ecibus_acc_read_reg(u8 reg, u8 *buf, int count)
+{
+ s32 ret;
+ int i;
+
+ if (reg > ECICMD_RESERVED)
+ return -EINVAL;
+
+ the_ed->wait_data = false;
+ if (ecibus_fire_acc_read_reg(reg, count))
+ return -EIO;
+
+ if (!wait_event_timeout(the_ed->wait, the_ed->wait_data == true,
+ msecs_to_jiffies(ECIBUS_WAIT_IRQ)))
+ return -EIO;
+
+ for (i = 0; i < count; i++) {
+ ret = ecibus_ctrl_read_reg(ECIREG_READ_DIRECT + i);
+ if (ret < 0)
+ return ret;
+
+ buf[i] = ret;
+ }
+
+ return 0;
+}
+
+/* ECI accessory register write */
+static int ecibus_acc_write_reg(u8 reg, u8 param)
+{
+ if (reg > ECICMD_RESERVED)
+ return -EINVAL;
+
+ return i2c_smbus_write_byte_data(the_ed->client, reg, param);
+}
+
+
+/*
+ * Struct eci_data is ECI input driver (dealing ECI accessories) data.
+ * Struct ecibus_data is this driver data, dealing just ECI communication.
+ * Global eci_register() pairs structs so that we can call ECI input driver
+ * event function with eci_data
+ */
+static void ecibus_emit_buttons(struct ecibus_data *ed, bool force_up)
+{
+ struct eci_data *eci = ed->eci_callback->priv;
+ struct eci_buttons_data *b = &eci->buttons_data;
+
+ if (force_up)
+ b->buttons = b->buttons_up_mask;
+
+ ed->eci_callback->event(ECI_EVENT_BUTTON, eci);
+}
+
+static void ecibus_get_buttons(u8 *buf)
+{
+ int i, ret;
+
+ for (i = 0; i < 2; i++) {
+ ret = ecibus_ctrl_read_reg(ECIREG_READ_DIRECT + i);
+ buf[i] = ret;
+ }
+}
+
+static irqreturn_t ecibus_irq_handler(int irq, void *_ed)
+{
+ struct ecibus_data *ed = _ed;
+ struct eci_data *eci = ed->eci_callback->priv;
+ struct eci_buttons_data *b = &eci->buttons_data;
+ int status;
+ char buf[4];
+
+ /* Clears ecibus DATA interrupt */
+ status = ecibus_ctrl_read_reg(ECIREG_STATUS);
+
+ if (status & ECIBUS_STATUS_DATA_READY) {
+ /*
+ * Buttons are special case as we want be fast with them
+ * and this way we cope with nested button and data interrupts
+ */
+ if (ed->wait_eci_buttons) {
+ ecibus_get_buttons(buf);
+ b->buttons = cpu_to_le32(*(u32 *)buf);
+ ecibus_emit_buttons(ed, ECI_REAL_BUTTONS);
+ ed->wait_eci_buttons = false;
+ }
+ /* Complete ECI data reading */
+ ed->wait_data = true;
+ wake_up(&ed->wait);
+ }
+
+ /* Accessory interrupt, ie. button pressed */
+ if (status & ECIBUS_STATUS_ACCESSORY_INT) {
+ if (eci->mem_ok) {
+ ecibus_fire_acc_read_reg(ECICMD_PORT_DATA_0, 2);
+ ed->wait_eci_buttons = true;
+ }
+ }
+
+ return IRQ_HANDLED;
+}
+
+static struct eci_hw_ops ecibus_hw_ops = {
+ .acc_reset = ecibus_acc_reset,
+ .acc_read_direct = ecibus_acc_read_direct,
+ .acc_read_reg = ecibus_acc_read_reg,
+ .acc_write_reg = ecibus_acc_write_reg,
+};
+
+static int __init ecibus_probe(struct platform_device *pdev)
+{
+ struct ecibus_data *ed;
+ struct ecibus_platform_data *pdata = pdev->dev.platform_data;
+ struct i2c_adapter *adapter;
+ int ret;
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "platform_data not available: %d\n",
+ __LINE__);
+ return -EINVAL;
+ }
+
+ ed = kzalloc(sizeof(*ed), GFP_KERNEL);
+ if (!ed)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, ed);
+ ed->dev = &pdev->dev;
+ ed->ecibus_rst_gpio = pdata->ecibus_rst_gpio;
+ ed->ecibus_sw_ctrl_gpio = pdata->ecibus_sw_ctrl_gpio;
+ ed->ecibus_int_gpio = pdata->ecibus_int_gpio;
+
+ if (ed->ecibus_rst_gpio == 0 || ed->ecibus_sw_ctrl_gpio == 0 ||
+ ed->ecibus_int_gpio == 0) {
+ ret = -ENXIO;
+ goto gpio_err;
+ }
+
+ the_ed = ed;
+
+ adapter = i2c_get_adapter(1);
+ if (adapter)
+ ed->client = i2c_new_device(adapter, &ecibus_i2c);
+ if (!ed->client) {
+ dev_err(ed->dev, "could not get i2c device %s at 0x%02x: %d\n",
+ ecibus_i2c.type, ecibus_i2c.addr, __LINE__);
+ kfree(ed);
+
+ return -ENODEV;
+ }
+
+ ret = ecibus_initialize_debugfs(ed);
+ if (ret)
+ dev_err(ed->dev, "could not create debugfs entries: %d\n",
+ __LINE__);
+
+ ret = gpio_request(ed->ecibus_rst_gpio, "ECI_RSTn");
+ if (ret) {
+ dev_err(ed->dev, "could not request ECI_RSTn gpio %d: %d\n",
+ ed->ecibus_rst_gpio, __LINE__);
+ goto rst_gpio_err;
+ }
+
+ gpio_direction_output(ed->ecibus_rst_gpio, 0);
+ gpio_set_value(ed->ecibus_rst_gpio, 1);
+
+ ret = gpio_request(ed->ecibus_sw_ctrl_gpio, "ECI_SW_CTRL");
+ if (ret) {
+ dev_err(ed->dev, "could not request ECI_SW_CTRL gpio %d: %d\n",
+ ed->ecibus_sw_ctrl_gpio, __LINE__);
+ goto sw_ctrl_gpio_err;
+ }
+
+ gpio_direction_input(ed->ecibus_sw_ctrl_gpio);
+
+ ret = gpio_request(ed->ecibus_int_gpio, "ECI_INT");
+ if (ret) {
+ dev_err(ed->dev, "could not request ECI_INT gpio %d: %d\n",
+ ed->ecibus_int_gpio, __LINE__);
+ goto int_gpio_err;
+ }
+
+ gpio_direction_input(ed->ecibus_int_gpio);
+
+ ret = request_threaded_irq(gpio_to_irq(ed->ecibus_int_gpio), NULL,
+ ecibus_irq_handler, IRQF_TRIGGER_RISING, "ECI_INT", ed);
+ if (ret) {
+ dev_err(ed->dev, "could not request irq %d: %d\n",
+ gpio_to_irq(ed->ecibus_int_gpio), __LINE__);
+ goto int_irq_err;
+ }
+
+ /* Register itself to the ECI accessory driver */
+ ed->eci_callback = eci_register(&ecibus_hw_ops);
+ if (IS_ERR(ed->eci_callback)) {
+ ret = PTR_ERR(ed->eci_callback);
+ goto eci_register_err;
+
+ }
+
+ /*
+ * Turn on vprog2
+ * Some decent power ctrl interface, please
+ */
+ intel_scu_ipc_iowrite8(AvP_MSIC_VPROG2, AvP_MSIC_VPROG2_2V5_ON);
+
+ init_waitqueue_head(&ed->wait);
+
+ return 0;
+
+eci_register_err:
+ free_irq(gpio_to_irq(ed->ecibus_int_gpio), ed);
+int_irq_err:
+ gpio_free(ed->ecibus_int_gpio);
+int_gpio_err:
+ gpio_free(ed->ecibus_sw_ctrl_gpio);
+sw_ctrl_gpio_err:
+ gpio_set_value(ed->ecibus_rst_gpio, 0);
+ gpio_free(ed->ecibus_rst_gpio);
+rst_gpio_err:
+ ecibus_uninitialize_debugfs();
+ i2c_unregister_device(ed->client);
+gpio_err:
+ kfree(ed);
+
+ return ret;
+}
+
+static int __exit ecibus_remove(struct platform_device *pdev)
+{
+ struct ecibus_data *ed = platform_get_drvdata(pdev);
+
+ gpio_set_value(ed->ecibus_rst_gpio, 0);
+ gpio_free(ed->ecibus_rst_gpio);
+
+ gpio_free(ed->ecibus_sw_ctrl_gpio);
+
+ free_irq(gpio_to_irq(ed->ecibus_int_gpio), ed);
+ gpio_free(ed->ecibus_int_gpio);
+
+ ecibus_uninitialize_debugfs();
+ i2c_unregister_device(ed->client);
+
+ /*
+ * Turn off vprog2
+ * Some decent power ctrl interface, please
+ */
+ intel_scu_ipc_iowrite8(AvP_MSIC_VPROG2, AvP_MSIC_VPROG2_2V5_OFF);
+
+ kfree(ed);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int ecibus_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+ return -ENOSYS;
+}
+#else
+#define ecibus_suspend NULL
+#endif
+
+static struct platform_driver ecibus_driver = {
+ .driver = {
+ .name = "ecibus",
+ .owner = THIS_MODULE,
+ },
+ .suspend = ecibus_suspend,
+ .remove = __exit_p(ecibus_remove),
+};
+
+static int __init ecibus_init(void)
+{
+ return platform_driver_probe(&ecibus_driver, ecibus_probe);
+}
+module_init(ecibus_init);
+
+static void __exit ecibus_exit(void)
+{
+
+ platform_driver_unregister(&ecibus_driver);
+}
+module_exit(ecibus_exit);
+
+MODULE_DESCRIPTION("ECI accessory controller driver");
+MODULE_AUTHOR("Nokia Corporation");
+MODULE_ALIAS("platform:ecibus");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/input/eci.h b/include/linux/input/eci.h
index b8be99c..a9d1008 100644
--- a/include/linux/input/eci.h
+++ b/include/linux/input/eci.h
@@ -154,4 +154,12 @@ struct eci_data {
};
struct eci_cb *eci_register(struct eci_hw_ops *eci_ops);
+
+/* ecibus controller data */
+struct ecibus_platform_data {
+ int ecibus_rst_gpio;
+ int ecibus_sw_ctrl_gpio;
+ int ecibus_int_gpio;
+};
+
#endif
--
1.6.5
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