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>hifive-unleashed-5.1
Simon Glass
Samuel Ortiz
parent
deaf39efbc
commit
4ab6174e8c
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@ -0,0 +1,56 @@
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ChromeOS Embedded Controller
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Google's ChromeOS EC is a Cortex-M device which talks to the AP and
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implements various function such as keyboard and battery charging.
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The EC can be connect through various means (I2C, SPI, LPC) and the
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compatible string used depends on the inteface. Each connection method has
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its own driver which connects to the top level interface-agnostic EC driver.
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Other Linux driver (such as cros-ec-keyb for the matrix keyboard) connect to
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the top-level driver.
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Required properties (I2C):
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- compatible: "google,cros-ec-i2c"
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- reg: I2C slave address
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Required properties (SPI):
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- compatible: "google,cros-ec-spi"
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- reg: SPI chip select
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Required properties (LPC):
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- compatible: "google,cros-ec-lpc"
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- reg: List of (IO address, size) pairs defining the interface uses
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Example for I2C:
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i2c@12CA0000 {
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cros-ec@1e {
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reg = <0x1e>;
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compatible = "google,cros-ec-i2c";
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interrupts = <14 0>;
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interrupt-parent = <&wakeup_eint>;
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wakeup-source;
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};
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Example for SPI:
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spi@131b0000 {
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ec@0 {
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compatible = "google,cros-ec-spi";
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reg = <0x0>;
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interrupts = <14 0>;
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interrupt-parent = <&wakeup_eint>;
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wakeup-source;
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spi-max-frequency = <5000000>;
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controller-data {
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cs-gpio = <&gpf0 3 4 3 0>;
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samsung,spi-cs;
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samsung,spi-feedback-delay = <2>;
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};
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};
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};
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Example for LPC is not supplied as it is not yet implemented.
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@ -21,6 +21,14 @@ config MFD_88PM860X
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select individual components like voltage regulators, RTC and
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battery-charger under the corresponding menus.
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config MFD_CROS_EC
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tristate "Support ChromeOS Embedded Controller"
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help
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If you say Y here you get support for the ChromeOS Embedded
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Controller (EC) providing keyboard, battery and power services.
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You also ned to enable the driver for the bus you are using. The
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protocol for talking to the EC is defined by the bus driver.
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config MFD_88PM800
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tristate "Support Marvell 88PM800"
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depends on I2C=y && GENERIC_HARDIRQS
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@ -8,6 +8,7 @@ obj-$(CONFIG_MFD_88PM800) += 88pm800.o 88pm80x.o
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obj-$(CONFIG_MFD_88PM805) += 88pm805.o 88pm80x.o
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obj-$(CONFIG_MFD_SM501) += sm501.o
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obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o
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obj-$(CONFIG_MFD_CROS_EC) += cros_ec.o
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rtsx_pci-objs := rtsx_pcr.o rts5209.o rts5229.o rtl8411.o rts5227.o
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obj-$(CONFIG_MFD_RTSX_PCI) += rtsx_pci.o
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@ -0,0 +1,189 @@
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/*
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* ChromeOS EC multi-function device
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*
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* Copyright (C) 2012 Google, Inc
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* The ChromeOS EC multi function device is used to mux all the requests
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* to the EC device for its multiple features: keyboard controller,
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* battery charging and regulator control, firmware update.
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*/
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/mfd/core.h>
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#include <linux/mfd/cros_ec.h>
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#include <linux/mfd/cros_ec_commands.h>
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int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
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struct cros_ec_msg *msg)
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{
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uint8_t *out;
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int csum, i;
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BUG_ON(msg->out_len > EC_HOST_PARAM_SIZE);
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out = ec_dev->dout;
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out[0] = EC_CMD_VERSION0 + msg->version;
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out[1] = msg->cmd;
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out[2] = msg->out_len;
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csum = out[0] + out[1] + out[2];
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for (i = 0; i < msg->out_len; i++)
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csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->out_buf[i];
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out[EC_MSG_TX_HEADER_BYTES + msg->out_len] = (uint8_t)(csum & 0xff);
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return EC_MSG_TX_PROTO_BYTES + msg->out_len;
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}
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static int cros_ec_command_sendrecv(struct cros_ec_device *ec_dev,
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uint16_t cmd, void *out_buf, int out_len,
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void *in_buf, int in_len)
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{
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struct cros_ec_msg msg;
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msg.version = cmd >> 8;
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msg.cmd = cmd & 0xff;
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msg.out_buf = out_buf;
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msg.out_len = out_len;
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msg.in_buf = in_buf;
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msg.in_len = in_len;
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return ec_dev->command_xfer(ec_dev, &msg);
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}
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static int cros_ec_command_recv(struct cros_ec_device *ec_dev,
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uint16_t cmd, void *buf, int buf_len)
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{
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return cros_ec_command_sendrecv(ec_dev, cmd, NULL, 0, buf, buf_len);
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}
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static int cros_ec_command_send(struct cros_ec_device *ec_dev,
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uint16_t cmd, void *buf, int buf_len)
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{
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return cros_ec_command_sendrecv(ec_dev, cmd, buf, buf_len, NULL, 0);
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}
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static irqreturn_t ec_irq_thread(int irq, void *data)
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{
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struct cros_ec_device *ec_dev = data;
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if (device_may_wakeup(ec_dev->dev))
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pm_wakeup_event(ec_dev->dev, 0);
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blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev);
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return IRQ_HANDLED;
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}
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static struct mfd_cell cros_devs[] = {
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{
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.name = "cros-ec-keyb",
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.id = 1,
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.of_compatible = "google,cros-ec-keyb",
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},
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};
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int cros_ec_register(struct cros_ec_device *ec_dev)
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{
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struct device *dev = ec_dev->dev;
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int err = 0;
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BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier);
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ec_dev->command_send = cros_ec_command_send;
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ec_dev->command_recv = cros_ec_command_recv;
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ec_dev->command_sendrecv = cros_ec_command_sendrecv;
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if (ec_dev->din_size) {
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ec_dev->din = kmalloc(ec_dev->din_size, GFP_KERNEL);
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if (!ec_dev->din) {
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err = -ENOMEM;
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goto fail_din;
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}
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}
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if (ec_dev->dout_size) {
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ec_dev->dout = kmalloc(ec_dev->dout_size, GFP_KERNEL);
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if (!ec_dev->dout) {
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err = -ENOMEM;
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goto fail_dout;
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}
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}
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if (!ec_dev->irq) {
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dev_dbg(dev, "no valid IRQ: %d\n", ec_dev->irq);
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goto fail_irq;
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}
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err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread,
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IRQF_TRIGGER_LOW | IRQF_ONESHOT,
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"chromeos-ec", ec_dev);
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if (err) {
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dev_err(dev, "request irq %d: error %d\n", ec_dev->irq, err);
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goto fail_irq;
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}
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err = mfd_add_devices(dev, 0, cros_devs,
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ARRAY_SIZE(cros_devs),
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NULL, ec_dev->irq, NULL);
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if (err) {
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dev_err(dev, "failed to add mfd devices\n");
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goto fail_mfd;
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}
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dev_info(dev, "Chrome EC (%s)\n", ec_dev->name);
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return 0;
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fail_mfd:
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free_irq(ec_dev->irq, ec_dev);
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fail_irq:
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kfree(ec_dev->dout);
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fail_dout:
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kfree(ec_dev->din);
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fail_din:
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return err;
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}
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int cros_ec_remove(struct cros_ec_device *ec_dev)
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{
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mfd_remove_devices(ec_dev->dev);
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free_irq(ec_dev->irq, ec_dev);
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kfree(ec_dev->dout);
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kfree(ec_dev->din);
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return 0;
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}
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#ifdef CONFIG_PM_SLEEP
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int cros_ec_suspend(struct cros_ec_device *ec_dev)
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{
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struct device *dev = ec_dev->dev;
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if (device_may_wakeup(dev))
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ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
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disable_irq(ec_dev->irq);
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ec_dev->was_wake_device = ec_dev->wake_enabled;
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return 0;
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}
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int cros_ec_resume(struct cros_ec_device *ec_dev)
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{
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enable_irq(ec_dev->irq);
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if (ec_dev->wake_enabled) {
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disable_irq_wake(ec_dev->irq);
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ec_dev->wake_enabled = 0;
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}
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return 0;
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}
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#endif
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@ -0,0 +1,170 @@
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/*
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* ChromeOS EC multi-function device
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*
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* Copyright (C) 2012 Google, Inc
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef __LINUX_MFD_CROS_EC_H
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#define __LINUX_MFD_CROS_EC_H
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#include <linux/mfd/cros_ec_commands.h>
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/*
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* Command interface between EC and AP, for LPC, I2C and SPI interfaces.
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*/
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enum {
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EC_MSG_TX_HEADER_BYTES = 3,
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EC_MSG_TX_TRAILER_BYTES = 1,
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EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES +
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EC_MSG_TX_TRAILER_BYTES,
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EC_MSG_RX_PROTO_BYTES = 3,
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/* Max length of messages */
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EC_MSG_BYTES = EC_HOST_PARAM_SIZE + EC_MSG_TX_PROTO_BYTES,
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};
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/**
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* struct cros_ec_msg - A message sent to the EC, and its reply
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*
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* @version: Command version number (often 0)
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* @cmd: Command to send (EC_CMD_...)
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* @out_buf: Outgoing payload (to EC)
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* @outlen: Outgoing length
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* @in_buf: Incoming payload (from EC)
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* @in_len: Incoming length
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*/
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struct cros_ec_msg {
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u8 version;
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u8 cmd;
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uint8_t *out_buf;
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int out_len;
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uint8_t *in_buf;
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int in_len;
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};
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/**
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* struct cros_ec_device - Information about a ChromeOS EC device
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*
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* @name: Name of this EC interface
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* @priv: Private data
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* @irq: Interrupt to use
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* @din: input buffer (from EC)
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* @dout: output buffer (to EC)
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* \note
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* These two buffers will always be dword-aligned and include enough
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* space for up to 7 word-alignment bytes also, so we can ensure that
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* the body of the message is always dword-aligned (64-bit).
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*
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* We use this alignment to keep ARM and x86 happy. Probably word
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* alignment would be OK, there might be a small performance advantage
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* to using dword.
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* @din_size: size of din buffer
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* @dout_size: size of dout buffer
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* @command_send: send a command
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* @command_recv: receive a command
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* @ec_name: name of EC device (e.g. 'chromeos-ec')
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* @phys_name: name of physical comms layer (e.g. 'i2c-4')
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* @parent: pointer to parent device (e.g. i2c or spi device)
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* @dev: Device pointer
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* dev_lock: Lock to prevent concurrent access
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* @wake_enabled: true if this device can wake the system from sleep
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* @was_wake_device: true if this device was set to wake the system from
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* sleep at the last suspend
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* @event_notifier: interrupt event notifier for transport devices
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*/
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struct cros_ec_device {
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const char *name;
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void *priv;
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int irq;
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uint8_t *din;
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uint8_t *dout;
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int din_size;
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int dout_size;
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int (*command_send)(struct cros_ec_device *ec,
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uint16_t cmd, void *out_buf, int out_len);
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int (*command_recv)(struct cros_ec_device *ec,
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uint16_t cmd, void *in_buf, int in_len);
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int (*command_sendrecv)(struct cros_ec_device *ec,
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uint16_t cmd, void *out_buf, int out_len,
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void *in_buf, int in_len);
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int (*command_xfer)(struct cros_ec_device *ec,
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struct cros_ec_msg *msg);
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const char *ec_name;
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const char *phys_name;
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struct device *parent;
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/* These are --private-- fields - do not assign */
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struct device *dev;
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struct mutex dev_lock;
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bool wake_enabled;
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bool was_wake_device;
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struct blocking_notifier_head event_notifier;
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};
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/**
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* cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
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*
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* This can be called by drivers to handle a suspend event.
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*
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* ec_dev: Device to suspend
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_suspend(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_resume - Handle a resume operation for the ChromeOS EC device
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*
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* This can be called by drivers to handle a resume event.
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*
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* @ec_dev: Device to resume
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_resume(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_prepare_tx - Prepare an outgoing message in the output buffer
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*
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* This is intended to be used by all ChromeOS EC drivers, but at present
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* only SPI uses it. Once LPC uses the same protocol it can start using it.
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* I2C could use it now, with a refactor of the existing code.
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*
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* @ec_dev: Device to register
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* @msg: Message to write
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*/
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int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
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struct cros_ec_msg *msg);
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/**
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* cros_ec_remove - Remove a ChromeOS EC
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*
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* Call this to deregister a ChromeOS EC. After this you should call
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* cros_ec_free().
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*
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* @ec_dev: Device to register
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_remove(struct cros_ec_device *ec_dev);
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/**
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* cros_ec_register - Register a new ChromeOS EC, using the provided info
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*
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* Before calling this, allocate a pointer to a new device and then fill
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* in all the fields up to the --private-- marker.
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*
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* @ec_dev: Device to register
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* @return 0 if ok, -ve on error
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*/
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int cros_ec_register(struct cros_ec_device *ec_dev);
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#endif /* __LINUX_MFD_CROS_EC_H */
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Loading…
Reference in New Issue