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authorSimon Glass <sjg@chromium.org>2013-02-26 02:08:37 +0400
committerSamuel Ortiz <sameo@linux.intel.com>2013-04-05 13:20:13 +0400
commit4ab6174e8cdb007cf500e484bdf454b8d14d524a (patch)
tree765eb600ad56a1f3271ad23aac795d91a35bd181 /drivers/mfd/cros_ec.c
parentdeaf39efbc0829f26ae0b8fbe5de820588982f72 (diff)
downloadlinux-4ab6174e8cdb007cf500e484bdf454b8d14d524a.tar.xz
mfd: Add ChromeOS EC implementation
This is the base EC implementation, which provides a high level interface to the EC for use by the rest of the kernel. The actual communcations is dealt with by a separate protocol driver which registers itself with this interface. Interrupts are passed on through a notifier. A simple message structure is used to pass messages to the protocol driver. Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Che-Liang Chiou <clchiou@chromium.org> Signed-off-by: Jonathan Kliegman <kliegs@chromium.org> Signed-off-by: Luigi Semenzato <semenzato@chromium.org> Signed-off-by: Olof Johansson <olofj@chromium.org> Signed-off-by: Vincent Palatin <vpalatin@chromium.org> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/mfd/cros_ec.c')
-rw-r--r--drivers/mfd/cros_ec.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
new file mode 100644
index 000000000000..ac824ccab52a
--- /dev/null
+++ b/drivers/mfd/cros_ec.c
@@ -0,0 +1,189 @@
+/*
+ * ChromeOS EC multi-function device
+ *
+ * Copyright (C) 2012 Google, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ * The ChromeOS EC multi function device is used to mux all the requests
+ * to the EC device for its multiple features: keyboard controller,
+ * battery charging and regulator control, firmware update.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+
+int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
+ struct cros_ec_msg *msg)
+{
+ uint8_t *out;
+ int csum, i;
+
+ BUG_ON(msg->out_len > EC_HOST_PARAM_SIZE);
+ out = ec_dev->dout;
+ out[0] = EC_CMD_VERSION0 + msg->version;
+ out[1] = msg->cmd;
+ out[2] = msg->out_len;
+ csum = out[0] + out[1] + out[2];
+ for (i = 0; i < msg->out_len; i++)
+ csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->out_buf[i];
+ out[EC_MSG_TX_HEADER_BYTES + msg->out_len] = (uint8_t)(csum & 0xff);
+
+ return EC_MSG_TX_PROTO_BYTES + msg->out_len;
+}
+
+static int cros_ec_command_sendrecv(struct cros_ec_device *ec_dev,
+ uint16_t cmd, void *out_buf, int out_len,
+ void *in_buf, int in_len)
+{
+ struct cros_ec_msg msg;
+
+ msg.version = cmd >> 8;
+ msg.cmd = cmd & 0xff;
+ msg.out_buf = out_buf;
+ msg.out_len = out_len;
+ msg.in_buf = in_buf;
+ msg.in_len = in_len;
+
+ return ec_dev->command_xfer(ec_dev, &msg);
+}
+
+static int cros_ec_command_recv(struct cros_ec_device *ec_dev,
+ uint16_t cmd, void *buf, int buf_len)
+{
+ return cros_ec_command_sendrecv(ec_dev, cmd, NULL, 0, buf, buf_len);
+}
+
+static int cros_ec_command_send(struct cros_ec_device *ec_dev,
+ uint16_t cmd, void *buf, int buf_len)
+{
+ return cros_ec_command_sendrecv(ec_dev, cmd, buf, buf_len, NULL, 0);
+}
+
+static irqreturn_t ec_irq_thread(int irq, void *data)
+{
+ struct cros_ec_device *ec_dev = data;
+
+ if (device_may_wakeup(ec_dev->dev))
+ pm_wakeup_event(ec_dev->dev, 0);
+
+ blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev);
+
+ return IRQ_HANDLED;
+}
+
+static struct mfd_cell cros_devs[] = {
+ {
+ .name = "cros-ec-keyb",
+ .id = 1,
+ .of_compatible = "google,cros-ec-keyb",
+ },
+};
+
+int cros_ec_register(struct cros_ec_device *ec_dev)
+{
+ struct device *dev = ec_dev->dev;
+ int err = 0;
+
+ BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
+
+ ec_dev->command_send = cros_ec_command_send;
+ ec_dev->command_recv = cros_ec_command_recv;
+ ec_dev->command_sendrecv = cros_ec_command_sendrecv;
+
+ if (ec_dev->din_size) {
+ ec_dev->din = kmalloc(ec_dev->din_size, GFP_KERNEL);
+ if (!ec_dev->din) {
+ err = -ENOMEM;
+ goto fail_din;
+ }
+ }
+ if (ec_dev->dout_size) {
+ ec_dev->dout = kmalloc(ec_dev->dout_size, GFP_KERNEL);
+ if (!ec_dev->dout) {
+ err = -ENOMEM;
+ goto fail_dout;
+ }
+ }
+
+ if (!ec_dev->irq) {
+ dev_dbg(dev, "no valid IRQ: %d\n", ec_dev->irq);
+ goto fail_irq;
+ }
+
+ err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ "chromeos-ec", ec_dev);
+ if (err) {
+ dev_err(dev, "request irq %d: error %d\n", ec_dev->irq, err);
+ goto fail_irq;
+ }
+
+ err = mfd_add_devices(dev, 0, cros_devs,
+ ARRAY_SIZE(cros_devs),
+ NULL, ec_dev->irq, NULL);
+ if (err) {
+ dev_err(dev, "failed to add mfd devices\n");
+ goto fail_mfd;
+ }
+
+ dev_info(dev, "Chrome EC (%s)\n", ec_dev->name);
+
+ return 0;
+
+fail_mfd:
+ free_irq(ec_dev->irq, ec_dev);
+fail_irq:
+ kfree(ec_dev->dout);
+fail_dout:
+ kfree(ec_dev->din);
+fail_din:
+ return err;
+}
+
+int cros_ec_remove(struct cros_ec_device *ec_dev)
+{
+ mfd_remove_devices(ec_dev->dev);
+ free_irq(ec_dev->irq, ec_dev);
+ kfree(ec_dev->dout);
+ kfree(ec_dev->din);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+int cros_ec_suspend(struct cros_ec_device *ec_dev)
+{
+ struct device *dev = ec_dev->dev;
+
+ if (device_may_wakeup(dev))
+ ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
+
+ disable_irq(ec_dev->irq);
+ ec_dev->was_wake_device = ec_dev->wake_enabled;
+
+ return 0;
+}
+
+int cros_ec_resume(struct cros_ec_device *ec_dev)
+{
+ enable_irq(ec_dev->irq);
+
+ if (ec_dev->wake_enabled) {
+ disable_irq_wake(ec_dev->irq);
+ ec_dev->wake_enabled = 0;
+ }
+
+ return 0;
+}
+#endif