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kernel/drivers/soc/ti/wkup_m3_ipc.c

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/*
* AMx3 Wkup M3 IPC driver
*
* Copyright (C) 2015 Texas Instruments, Inc.
*
* Dave Gerlach <d-gerlach@ti.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.
*/
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/omap-mailbox.h>
#include <linux/platform_device.h>
#include <linux/remoteproc.h>
#include <linux/suspend.h>
#include <linux/wkup_m3_ipc.h>
#define AM33XX_CTRL_IPC_REG_COUNT 0x8
#define AM33XX_CTRL_IPC_REG_OFFSET(m) (0x4 + 4 * (m))
/* AM33XX M3_TXEV_EOI register */
#define AM33XX_CONTROL_M3_TXEV_EOI 0x00
#define AM33XX_M3_TXEV_ACK (0x1 << 0)
#define AM33XX_M3_TXEV_ENABLE (0x0 << 0)
#define IPC_CMD_DS0 0x4
#define IPC_CMD_STANDBY 0xc
#define IPC_CMD_IDLE 0x10
#define IPC_CMD_RESET 0xe
#define DS_IPC_DEFAULT 0xffffffff
#define M3_VERSION_UNKNOWN 0x0000ffff
#define M3_BASELINE_VERSION 0x191
#define M3_STATUS_RESP_MASK (0xffff << 16)
#define M3_FW_VERSION_MASK 0xffff
#define M3_STATE_UNKNOWN 0
#define M3_STATE_RESET 1
#define M3_STATE_INITED 2
#define M3_STATE_MSG_FOR_LP 3
#define M3_STATE_MSG_FOR_RESET 4
static struct wkup_m3_ipc *m3_ipc_state;
static void am33xx_txev_eoi(struct wkup_m3_ipc *m3_ipc)
{
writel(AM33XX_M3_TXEV_ACK,
m3_ipc->ipc_mem_base + AM33XX_CONTROL_M3_TXEV_EOI);
}
static void am33xx_txev_enable(struct wkup_m3_ipc *m3_ipc)
{
writel(AM33XX_M3_TXEV_ENABLE,
m3_ipc->ipc_mem_base + AM33XX_CONTROL_M3_TXEV_EOI);
}
static void wkup_m3_ctrl_ipc_write(struct wkup_m3_ipc *m3_ipc,
u32 val, int ipc_reg_num)
{
if (WARN(ipc_reg_num < 0 || ipc_reg_num > AM33XX_CTRL_IPC_REG_COUNT,
"ipc register operation out of range"))
return;
writel(val, m3_ipc->ipc_mem_base +
AM33XX_CTRL_IPC_REG_OFFSET(ipc_reg_num));
}
static unsigned int wkup_m3_ctrl_ipc_read(struct wkup_m3_ipc *m3_ipc,
int ipc_reg_num)
{
if (WARN(ipc_reg_num < 0 || ipc_reg_num > AM33XX_CTRL_IPC_REG_COUNT,
"ipc register operation out of range"))
return 0;
return readl(m3_ipc->ipc_mem_base +
AM33XX_CTRL_IPC_REG_OFFSET(ipc_reg_num));
}
static int wkup_m3_fw_version_read(struct wkup_m3_ipc *m3_ipc)
{
int val;
val = wkup_m3_ctrl_ipc_read(m3_ipc, 2);
return val & M3_FW_VERSION_MASK;
}
static irqreturn_t wkup_m3_txev_handler(int irq, void *ipc_data)
{
struct wkup_m3_ipc *m3_ipc = ipc_data;
struct device *dev = m3_ipc->dev;
int ver = 0;
am33xx_txev_eoi(m3_ipc);
switch (m3_ipc->state) {
case M3_STATE_RESET:
ver = wkup_m3_fw_version_read(m3_ipc);
if (ver == M3_VERSION_UNKNOWN ||
ver < M3_BASELINE_VERSION) {
dev_warn(dev, "CM3 Firmware Version %x not supported\n",
ver);
} else {
dev_info(dev, "CM3 Firmware Version = 0x%x\n", ver);
}
m3_ipc->state = M3_STATE_INITED;
complete(&m3_ipc->sync_complete);
break;
case M3_STATE_MSG_FOR_RESET:
m3_ipc->state = M3_STATE_INITED;
complete(&m3_ipc->sync_complete);
break;
case M3_STATE_MSG_FOR_LP:
complete(&m3_ipc->sync_complete);
break;
case M3_STATE_UNKNOWN:
dev_warn(dev, "Unknown CM3 State\n");
}
am33xx_txev_enable(m3_ipc);
return IRQ_HANDLED;
}
static int wkup_m3_ping(struct wkup_m3_ipc *m3_ipc)
{
struct device *dev = m3_ipc->dev;
mbox_msg_t dummy_msg = 0;
int ret;
if (!m3_ipc->mbox) {
dev_err(dev,
"No IPC channel to communicate with wkup_m3!\n");
return -EIO;
}
/*
* Write a dummy message to the mailbox in order to trigger the RX
* interrupt to alert the M3 that data is available in the IPC
* registers. We must enable the IRQ here and disable it after in
* the RX callback to avoid multiple interrupts being received
* by the CM3.
*/
ret = mbox_send_message(m3_ipc->mbox, &dummy_msg);
if (ret < 0) {
dev_err(dev, "%s: mbox_send_message() failed: %d\n",
__func__, ret);
return ret;
}
ret = wait_for_completion_timeout(&m3_ipc->sync_complete,
msecs_to_jiffies(500));
if (!ret) {
dev_err(dev, "MPU<->CM3 sync failure\n");
m3_ipc->state = M3_STATE_UNKNOWN;
return -EIO;
}
mbox_client_txdone(m3_ipc->mbox, 0);
return 0;
}
static int wkup_m3_ping_noirq(struct wkup_m3_ipc *m3_ipc)
{
struct device *dev = m3_ipc->dev;
mbox_msg_t dummy_msg = 0;
int ret;
if (!m3_ipc->mbox) {
dev_err(dev,
"No IPC channel to communicate with wkup_m3!\n");
return -EIO;
}
ret = mbox_send_message(m3_ipc->mbox, &dummy_msg);
if (ret < 0) {
dev_err(dev, "%s: mbox_send_message() failed: %d\n",
__func__, ret);
return ret;
}
mbox_client_txdone(m3_ipc->mbox, 0);
return 0;
}
static int wkup_m3_is_available(struct wkup_m3_ipc *m3_ipc)
{
return ((m3_ipc->state != M3_STATE_RESET) &&
(m3_ipc->state != M3_STATE_UNKNOWN));
}
/* Public functions */
/**
* wkup_m3_set_mem_type - Pass wkup_m3 which type of memory is in use
* @mem_type: memory type value read directly from emif
*
* wkup_m3 must know what memory type is in use to properly suspend
* and resume.
*/
static void wkup_m3_set_mem_type(struct wkup_m3_ipc *m3_ipc, int mem_type)
{
m3_ipc->mem_type = mem_type;
}
/**
* wkup_m3_set_resume_address - Pass wkup_m3 resume address
* @addr: Physical address from which resume code should execute
*/
static void wkup_m3_set_resume_address(struct wkup_m3_ipc *m3_ipc, void *addr)
{
m3_ipc->resume_addr = (unsigned long)addr;
}
/**
* wkup_m3_request_pm_status - Retrieve wkup_m3 status code after suspend
*
* Returns code representing the status of a low power mode transition.
* 0 - Successful transition
* 1 - Failure to transition to low power state
*/
static int wkup_m3_request_pm_status(struct wkup_m3_ipc *m3_ipc)
{
unsigned int i;
int val;
val = wkup_m3_ctrl_ipc_read(m3_ipc, 1);
i = M3_STATUS_RESP_MASK & val;
i >>= __ffs(M3_STATUS_RESP_MASK);
return i;
}
/**
* wkup_m3_prepare_low_power - Request preparation for transition to
* low power state
* @state: A kernel suspend state to enter, either MEM or STANDBY
*
* Returns 0 if preparation was successful, otherwise returns error code
*/
static int wkup_m3_prepare_low_power(struct wkup_m3_ipc *m3_ipc, int state)
{
struct device *dev = m3_ipc->dev;
int m3_power_state;
int ret = 0;
if (!wkup_m3_is_available(m3_ipc))
return -ENODEV;
switch (state) {
case WKUP_M3_DEEPSLEEP:
m3_power_state = IPC_CMD_DS0;
break;
case WKUP_M3_STANDBY:
m3_power_state = IPC_CMD_STANDBY;
break;
case WKUP_M3_IDLE:
m3_power_state = IPC_CMD_IDLE;
break;
default:
return 1;
}
/* Program each required IPC register then write defaults to others */
wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->resume_addr, 0);
wkup_m3_ctrl_ipc_write(m3_ipc, m3_power_state, 1);
wkup_m3_ctrl_ipc_write(m3_ipc, m3_ipc->mem_type, 4);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 3);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 5);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 6);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 7);
m3_ipc->state = M3_STATE_MSG_FOR_LP;
if (state == WKUP_M3_IDLE)
ret = wkup_m3_ping_noirq(m3_ipc);
else
ret = wkup_m3_ping(m3_ipc);
if (ret) {
dev_err(dev, "Unable to ping CM3\n");
return ret;
}
return 0;
}
/**
* wkup_m3_finish_low_power - Return m3 to reset state
*
* Returns 0 if reset was successful, otherwise returns error code
*/
static int wkup_m3_finish_low_power(struct wkup_m3_ipc *m3_ipc)
{
struct device *dev = m3_ipc->dev;
int ret = 0;
if (!wkup_m3_is_available(m3_ipc))
return -ENODEV;
wkup_m3_ctrl_ipc_write(m3_ipc, IPC_CMD_RESET, 1);
wkup_m3_ctrl_ipc_write(m3_ipc, DS_IPC_DEFAULT, 2);
m3_ipc->state = M3_STATE_MSG_FOR_RESET;
ret = wkup_m3_ping(m3_ipc);
if (ret) {
dev_err(dev, "Unable to ping CM3\n");
return ret;
}
return 0;
}
static struct wkup_m3_ipc_ops ipc_ops = {
.set_mem_type = wkup_m3_set_mem_type,
.set_resume_address = wkup_m3_set_resume_address,
.prepare_low_power = wkup_m3_prepare_low_power,
.finish_low_power = wkup_m3_finish_low_power,
.request_pm_status = wkup_m3_request_pm_status,
};
/**
* wkup_m3_ipc_get - Return handle to wkup_m3_ipc
*
* Returns NULL if the wkup_m3 is not yet available, otherwise returns
* pointer to wkup_m3_ipc struct.
*/
struct wkup_m3_ipc *wkup_m3_ipc_get(void)
{
if (m3_ipc_state)
get_device(m3_ipc_state->dev);
else
return NULL;
return m3_ipc_state;
}
EXPORT_SYMBOL_GPL(wkup_m3_ipc_get);
/**
* wkup_m3_ipc_put - Free handle to wkup_m3_ipc returned from wkup_m3_ipc_get
* @m3_ipc: A pointer to wkup_m3_ipc struct returned by wkup_m3_ipc_get
*/
void wkup_m3_ipc_put(struct wkup_m3_ipc *m3_ipc)
{
if (m3_ipc_state)
put_device(m3_ipc_state->dev);
}
EXPORT_SYMBOL_GPL(wkup_m3_ipc_put);
static void wkup_m3_rproc_boot_thread(struct wkup_m3_ipc *m3_ipc)
{
struct device *dev = m3_ipc->dev;
int ret;
init_completion(&m3_ipc->sync_complete);
ret = rproc_boot(m3_ipc->rproc);
if (ret)
dev_err(dev, "rproc_boot failed\n");
do_exit(0);
}
static int wkup_m3_ipc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int irq, ret;
phandle rproc_phandle;
struct rproc *m3_rproc;
struct resource *res;
struct task_struct *task;
struct wkup_m3_ipc *m3_ipc;
m3_ipc = devm_kzalloc(dev, sizeof(*m3_ipc), GFP_KERNEL);
if (!m3_ipc)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
m3_ipc->ipc_mem_base = devm_ioremap_resource(dev, res);
if (IS_ERR(m3_ipc->ipc_mem_base)) {
dev_err(dev, "could not ioremap ipc_mem\n");
return PTR_ERR(m3_ipc->ipc_mem_base);
}
irq = platform_get_irq(pdev, 0);
if (!irq) {
dev_err(&pdev->dev, "no irq resource\n");
return -ENXIO;
}
ret = devm_request_irq(dev, irq, wkup_m3_txev_handler,
0, "wkup_m3_txev", m3_ipc);
if (ret) {
dev_err(dev, "request_irq failed\n");
return ret;
}
m3_ipc->mbox_client.dev = dev;
m3_ipc->mbox_client.tx_done = NULL;
m3_ipc->mbox_client.tx_prepare = NULL;
m3_ipc->mbox_client.rx_callback = NULL;
m3_ipc->mbox_client.tx_block = false;
m3_ipc->mbox_client.knows_txdone = false;
m3_ipc->mbox = mbox_request_channel(&m3_ipc->mbox_client, 0);
if (IS_ERR(m3_ipc->mbox)) {
dev_err(dev, "IPC Request for A8->M3 Channel failed! %ld\n",
PTR_ERR(m3_ipc->mbox));
return PTR_ERR(m3_ipc->mbox);
}
if (of_property_read_u32(dev->of_node, "ti,rproc", &rproc_phandle)) {
dev_err(&pdev->dev, "could not get rproc phandle\n");
ret = -ENODEV;
goto err_free_mbox;
}
m3_rproc = rproc_get_by_phandle(rproc_phandle);
if (!m3_rproc) {
dev_err(&pdev->dev, "could not get rproc handle\n");
ret = -EPROBE_DEFER;
goto err_free_mbox;
}
m3_ipc->rproc = m3_rproc;
m3_ipc->dev = dev;
m3_ipc->state = M3_STATE_RESET;
m3_ipc->ops = &ipc_ops;
/*
* Wait for firmware loading completion in a thread so we
* can boot the wkup_m3 as soon as it's ready without holding
* up kernel boot
*/
task = kthread_run((void *)wkup_m3_rproc_boot_thread, m3_ipc,
"wkup_m3_rproc_loader");
if (IS_ERR(task)) {
dev_err(dev, "can't create rproc_boot thread\n");
ret = PTR_ERR(task);
goto err_put_rproc;
}
m3_ipc_state = m3_ipc;
return 0;
err_put_rproc:
rproc_put(m3_rproc);
err_free_mbox:
mbox_free_channel(m3_ipc->mbox);
return ret;
}
static int wkup_m3_ipc_remove(struct platform_device *pdev)
{
mbox_free_channel(m3_ipc_state->mbox);
rproc_shutdown(m3_ipc_state->rproc);
rproc_put(m3_ipc_state->rproc);
m3_ipc_state = NULL;
return 0;
}
static const struct of_device_id wkup_m3_ipc_of_match[] = {
{ .compatible = "ti,am3352-wkup-m3-ipc", },
{ .compatible = "ti,am4372-wkup-m3-ipc", },
{},
};
MODULE_DEVICE_TABLE(of, wkup_m3_ipc_of_match);
static struct platform_driver wkup_m3_ipc_driver = {
.probe = wkup_m3_ipc_probe,
.remove = wkup_m3_ipc_remove,
.driver = {
.name = "wkup_m3_ipc",
.of_match_table = wkup_m3_ipc_of_match,
},
};
module_platform_driver(wkup_m3_ipc_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("wkup m3 remote processor ipc driver");
MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
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