diff options
Diffstat (limited to 'drivers/soc/ti/wkup_m3_ipc.c')
| -rw-r--r-- | drivers/soc/ti/wkup_m3_ipc.c | 508 |
1 files changed, 508 insertions, 0 deletions
diff --git a/drivers/soc/ti/wkup_m3_ipc.c b/drivers/soc/ti/wkup_m3_ipc.c new file mode 100644 index 000000000000..8823cc81ae45 --- /dev/null +++ b/drivers/soc/ti/wkup_m3_ipc.c @@ -0,0 +1,508 @@ +/* + * 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; + + wait_for_completion(&m3_ipc->rproc->firmware_loading_complete); + + 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"); + 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>"); |