From patchwork Wed Nov 26 21:38:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Gerlach X-Patchwork-Id: 5388461 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id BC1CDC11AC for ; Wed, 26 Nov 2014 21:41:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 41D71201F5 for ; Wed, 26 Nov 2014 21:41:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86E37201EC for ; Wed, 26 Nov 2014 21:41:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753219AbaKZVjZ (ORCPT ); Wed, 26 Nov 2014 16:39:25 -0500 Received: from comal.ext.ti.com ([198.47.26.152]:59179 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752834AbaKZViv (ORCPT ); Wed, 26 Nov 2014 16:38:51 -0500 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by comal.ext.ti.com (8.13.7/8.13.7) with ESMTP id sAQLcNSX003168; Wed, 26 Nov 2014 15:38:23 -0600 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id sAQLcNdT003421; Wed, 26 Nov 2014 15:38:23 -0600 Received: from dlep32.itg.ti.com (157.170.170.100) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.174.1; Wed, 26 Nov 2014 15:38:23 -0600 Received: from legion.dal.design.ti.com (legion.dal.design.ti.com [128.247.22.53]) by dlep32.itg.ti.com (8.14.3/8.13.8) with ESMTP id sAQLcNan008155; Wed, 26 Nov 2014 15:38:23 -0600 Received: from localhost (j-172-22-146-2.vpn.ti.com [172.22.146.2]) by legion.dal.design.ti.com (8.11.7p1+Sun/8.11.7) with ESMTP id sAQLcMt15967; Wed, 26 Nov 2014 15:38:22 -0600 (CST) From: Dave Gerlach To: , , , CC: Tony Lindgren , Paul Walmsley , Benoit Cousson , Kevin Hilman , Ohad Ben-Cohen , Suman Anna , Dave Gerlach Subject: [RFC PATCH 2/3] soc: ti: Add wkup_m3_ipc driver Date: Wed, 26 Nov 2014 15:38:09 -0600 Message-ID: <3334d8483dca2d061cf43da9c047ec27f31e8719.1417029919.git.d-gerlach@ti.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: References: MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Introduce a wkup_m3_ipc driver to handle communication between the MPU and Cortex M3 wkup_m3 present on am335x. This driver is responsible for actually booting the wkup_m3_rproc and also handling all IPC which is done using the IPC registers in the control module, a mailbox, and a separate interrupt back from the wkup_m3. A small API is exposed for executing specific power commands, which include configuring for low power mode, request a transition to a low power mode, and status info on a previous transition. Signed-off-by: Dave Gerlach --- drivers/soc/ti/Kconfig | 11 + drivers/soc/ti/Makefile | 1 + drivers/soc/ti/wkup_m3_ipc.c | 503 +++++++++++++++++++++++++++++++++++++++++++ include/linux/wkup_m3_ipc.h | 33 +++ 4 files changed, 548 insertions(+) create mode 100644 drivers/soc/ti/wkup_m3_ipc.c create mode 100644 include/linux/wkup_m3_ipc.h diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig index 7266b21..61cda85 100644 --- a/drivers/soc/ti/Kconfig +++ b/drivers/soc/ti/Kconfig @@ -28,4 +28,15 @@ config KEYSTONE_NAVIGATOR_DMA If unsure, say N. +config WKUP_M3_IPC + bool "TI AM33XX Wkup-M3 IPC Driver" + depends on WKUP_M3_RPROC + select MAILBOX + select OMAP2PLUS_MBOX + help + TI AM33XX has a Cortex M3 to handle low power transitions. This IPC + driver provides the necessary API to communicate and use the wkup m3 + for PM features like Suspend/Resume and boots the wkup_m3 using + wkup_m3_rproc driver. + endif # SOC_TI diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile index 6bed611..b6b8c8b 100644 --- a/drivers/soc/ti/Makefile +++ b/drivers/soc/ti/Makefile @@ -3,3 +3,4 @@ # obj-$(CONFIG_KEYSTONE_NAVIGATOR_QMSS) += knav_qmss_queue.o knav_qmss_acc.o obj-$(CONFIG_KEYSTONE_NAVIGATOR_DMA) += knav_dma.o +obj-$(CONFIG_WKUP_M3_IPC) += wkup_m3_ipc.o diff --git a/drivers/soc/ti/wkup_m3_ipc.c b/drivers/soc/ti/wkup_m3_ipc.c new file mode 100644 index 0000000..f915da6 --- /dev/null +++ b/drivers/soc/ti/wkup_m3_ipc.c @@ -0,0 +1,503 @@ +/* + * AMx3 Wkup M3 IPC driver + * + * Copyright (C) 2014 Texas Instruments, Inc. + * + * Dave Gerlach + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#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_RESET 0xe +#define DS_IPC_DEFAULT 0xffffffff +#define M3_VERSION_UNKNOWN 0x0000ffff +#define M3_BASELINE_VERSION 0x187 +#define M3_WAKE_SRC_MASK 0xFF +#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 + +struct wkup_m3_wakeup_src { + int irq_nr; + char src[10]; +}; + +struct wkup_m3_ipc { + struct rproc *rproc; + + void __iomem *ipc_mem_base; + struct device *dev; + + int mem_type; + unsigned long resume_addr; + int state; + + struct mbox_client mbox_client; + struct mbox_chan *mbox; +}; + +static struct wkup_m3_ipc m3_ipc_state; + +static DECLARE_COMPLETION(m3_ipc_sync); + +static const struct wkup_m3_wakeup_src wakeups[] = { + {.irq_nr = 35, .src = "USB0_PHY"}, + {.irq_nr = 36, .src = "USB1_PHY"}, + {.irq_nr = 40, .src = "I2C0"}, + {.irq_nr = 41, .src = "RTC Timer"}, + {.irq_nr = 42, .src = "RTC Alarm"}, + {.irq_nr = 43, .src = "Timer0"}, + {.irq_nr = 44, .src = "Timer1"}, + {.irq_nr = 45, .src = "UART"}, + {.irq_nr = 46, .src = "GPIO0"}, + {.irq_nr = 48, .src = "MPU_WAKE"}, + {.irq_nr = 49, .src = "WDT0"}, + {.irq_nr = 50, .src = "WDT1"}, + {.irq_nr = 51, .src = "ADC_TSC"}, + {.irq_nr = 0, .src = "Unknown"}, +}; + +static inline 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 inline 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 inline void wkup_m3_ctrl_ipc_write(struct wkup_m3_ipc *m3_ipc, + u32 val, int ipc_reg_num) +{ + if (ipc_reg_num < 0 || ipc_reg_num > AM33XX_CTRL_IPC_REG_COUNT) + return; + + writel(val, m3_ipc->ipc_mem_base + + AM33XX_CTRL_IPC_REG_OFFSET(ipc_reg_num)); +} + +static inline unsigned int wkup_m3_ctrl_ipc_read(struct wkup_m3_ipc *m3_ipc, + int ipc_reg_num) +{ + if (ipc_reg_num < 0 || ipc_reg_num > AM33XX_CTRL_IPC_REG_COUNT) + return 0; + + return readl(m3_ipc->ipc_mem_base + + AM33XX_CTRL_IPC_REG_OFFSET(ipc_reg_num)); +} + +static int wkup_m3_fw_version_read(void) +{ + int val; + + val = wkup_m3_ctrl_ipc_read(&m3_ipc_state, 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 = (struct wkup_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(); + + 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); + break; + case M3_STATE_MSG_FOR_RESET: + m3_ipc->state = M3_STATE_INITED; + complete(&m3_ipc_sync); + break; + case M3_STATE_MSG_FOR_LP: + complete(&m3_ipc_sync); + break; + case M3_STATE_UNKNOWN: + dev_warn(dev, "Unknown CM3 State\n"); + } + + am33xx_txev_enable(m3_ipc); + + return IRQ_HANDLED; +} + +static void wkup_m3_mbox_callback(struct mbox_client *client, void *data) +{ + struct wkup_m3_ipc *m3_ipc = container_of(client, struct wkup_m3_ipc, + mbox_client); + + omap_mbox_disable_irq(m3_ipc->mbox, IRQ_RX); +} + +static int wkup_m3_ping(void) +{ + struct device *dev = m3_ipc_state.dev; + mbox_msg_t dummy_msg = 0; + int ret; + + if (!m3_ipc_state.mbox) { + dev_err(m3_ipc_state.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. + */ + omap_mbox_enable_irq(m3_ipc_state.mbox, IRQ_RX); + ret = mbox_send_message(m3_ipc_state.mbox, (void *)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, + msecs_to_jiffies(500)); + if (!ret) { + dev_err(dev, "MPU<->CM3 sync failure\n"); + m3_ipc_state.state = M3_STATE_UNKNOWN; + return -EIO; + } + + return 0; +} + +static const char *wkup_m3_request_wake_src(void) +{ + unsigned int wakeup_src_idx; + int j, val; + + val = wkup_m3_ctrl_ipc_read(&m3_ipc_state, 6); + + wakeup_src_idx = val & M3_WAKE_SRC_MASK; + + for (j = 0; j < ARRAY_SIZE(wakeups)-1; j++) { + if (wakeups[j].irq_nr == wakeup_src_idx) + return wakeups[j].src; + } + return wakeups[j].src; +} + +static int wkup_m3_is_available(void) +{ + return (m3_ipc_state.state != M3_STATE_RESET); +} + +/* 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. + */ +void wkup_m3_set_mem_type(int mem_type) +{ + m3_ipc_state.mem_type = mem_type; +} + +/** + * wkup_m3_set_resume_address - Pass wkup_m3 resume address + * @addr: Physical address from which resume code should execute + */ +void wkup_m3_set_resume_address(void *addr) +{ + m3_ipc_state.resume_addr = (unsigned long)addr; +} + +/** + * wkup_m3_set_resume_address - 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 + */ +int wkup_m3_request_pm_status(void) +{ + struct device *dev = m3_ipc_state.dev; + unsigned int i; + int val; + const char *wake_src; + + /* print the wakeup reason */ + wake_src = wkup_m3_request_wake_src(); + dev_dbg(dev, "Wakeup source %s\n", wake_src); + + val = wkup_m3_ctrl_ipc_read(&m3_ipc_state, 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 + */ +int wkup_m3_prepare_low_power(int state) +{ + struct device *dev = m3_ipc_state.dev; + int m3_power_state; + int ret = 0; + + if (!wkup_m3_is_available()) { + dev_err(dev, "wkup_m3 not available. DeepSleep entry not possible.\n"); + return -ENODEV; + } + + switch (state) { + case PM_SUSPEND_MEM: + m3_power_state = IPC_CMD_DS0; + break; + default: + return 1; + } + + /* Program each required IPC register then write defaults to others */ + wkup_m3_ctrl_ipc_write(&m3_ipc_state, m3_ipc_state.resume_addr, 0); + wkup_m3_ctrl_ipc_write(&m3_ipc_state, m3_power_state, 1); + wkup_m3_ctrl_ipc_write(&m3_ipc_state, m3_ipc_state.mem_type, 4); + + wkup_m3_ctrl_ipc_write(&m3_ipc_state, DS_IPC_DEFAULT, 2); + wkup_m3_ctrl_ipc_write(&m3_ipc_state, DS_IPC_DEFAULT, 3); + wkup_m3_ctrl_ipc_write(&m3_ipc_state, DS_IPC_DEFAULT, 5); + wkup_m3_ctrl_ipc_write(&m3_ipc_state, DS_IPC_DEFAULT, 6); + wkup_m3_ctrl_ipc_write(&m3_ipc_state, DS_IPC_DEFAULT, 7); + + m3_ipc_state.state = M3_STATE_MSG_FOR_LP; + + ret = wkup_m3_ping(); + 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 + */ +int wkup_m3_finish_low_power(void) +{ + struct device *dev = m3_ipc_state.dev; + int ret = 0; + + if (!wkup_m3_is_available()) + return -ENODEV; + + wkup_m3_ctrl_ipc_write(&m3_ipc_state, IPC_CMD_RESET, 1); + wkup_m3_ctrl_ipc_write(&m3_ipc_state, DS_IPC_DEFAULT, 2); + + m3_ipc_state.state = M3_STATE_MSG_FOR_RESET; + + ret = wkup_m3_ping(); + if (ret) { + dev_err(dev, "Unable to ping CM3\n"); + return ret; + } + + return 0; +} + +static int match(struct device *dev, void *data) +{ + struct device_node *node = (struct device_node *)data; + + return dev->of_node == node; +} + +static struct rproc *wkup_m3_get_rproc(struct device *dev) +{ + struct device_node *node; + struct rproc *rp; + + node = of_parse_phandle(dev->of_node, "ti,rproc", 0); + if (!node) + return NULL; + + dev = bus_find_device(&platform_bus_type, NULL, node, match); + if (!dev) + return NULL; + + rp = dev_get_drvdata(dev); + return rp; +} + +static void wkup_m3_rproc_boot_thread(struct rproc *rproc) +{ + struct device *dev = &rproc->dev; + int ret; + + wait_for_completion(&rproc->firmware_loading_complete); + + ret = rproc_boot(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; + struct rproc *m3_rproc; + struct resource *res; + struct task_struct *task; + + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ipc_regs"); + m3_ipc_state.ipc_mem_base = devm_ioremap_resource(dev, res); + if (IS_ERR(m3_ipc_state.ipc_mem_base)) { + dev_err(dev, "could not ioremap ipc_mem\n"); + ret = PTR_ERR(m3_ipc_state.ipc_mem_base); + goto err; + } + + irq = platform_get_irq(pdev, 0); + if (!irq) { + dev_err(&pdev->dev, "no irq resource\n"); + ret = -ENXIO; + goto err; + } + + ret = devm_request_irq(dev, irq, wkup_m3_txev_handler, + IRQF_DISABLED, "wkup_m3_txev", &m3_ipc_state); + if (ret) { + dev_err(dev, "request_irq failed\n"); + goto err; + } + + m3_ipc_state.mbox_client.dev = dev; + m3_ipc_state.mbox_client.tx_done = NULL; + m3_ipc_state.mbox_client.rx_callback = wkup_m3_mbox_callback; + m3_ipc_state.mbox_client.tx_block = false; + m3_ipc_state.mbox_client.knows_txdone = false; + + m3_ipc_state.mbox = mbox_request_channel(&m3_ipc_state.mbox_client, 0); + if (IS_ERR(m3_ipc_state.mbox)) { + dev_err(dev, "IPC Request for A8->M3 Channel failed! %ld\n", + PTR_ERR(m3_ipc_state.mbox)); + ret = PTR_ERR(m3_ipc_state.mbox); + m3_ipc_state.mbox = NULL; + return ret; + } + + m3_rproc = wkup_m3_get_rproc(dev); + if (!m3_rproc) { + ret = -EPROBE_DEFER; + goto err; + } + + m3_ipc_state.dev = dev; + m3_ipc_state.state = M3_STATE_RESET; + /* + * 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_rproc, + "wkup_m3_rproc_loader"); + + if (IS_ERR(task)) { + dev_err(dev, "can't create rproc_boot thread\n"); + goto err; + } + + return 0; + +err: + mbox_free_channel(m3_ipc_state.mbox); + return ret; +} + +static int wkup_m3_ipc_remove(struct platform_device *pdev) +{ + if (m3_ipc_state.mbox) + mbox_free_channel(m3_ipc_state.mbox); + + return 0; +} + +static const struct of_device_id wkup_m3_ipc_of_match[] = { + { .compatible = "ti,am3353-wkup-m3-ipc", .data = NULL, }, + {}, +}; + +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"); diff --git a/include/linux/wkup_m3_ipc.h b/include/linux/wkup_m3_ipc.h new file mode 100644 index 0000000..a0c2722 --- /dev/null +++ b/include/linux/wkup_m3_ipc.h @@ -0,0 +1,33 @@ +/* + * TI Wakeup M3 for AMx3 SoCs Power Management Routines + * + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/ + * Dave Gerlach + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _LINUX_WKUP_M3_H +#define _LINUX_WKUP_M3_H + +#ifdef CONFIG_WKUP_M3_IPC +void wkup_m3_set_mem_type(int mem_type); +void wkup_m3_set_resume_address(void *addr); +int wkup_m3_prepare_low_power(int state); +int wkup_m3_finish_low_power(void); +int wkup_m3_request_pm_status(void); +#else +static inline void wkup_m3_set_mem_type(int mem_type) { } +static inline void wkup_m3_set_resume_address(void *addr) { } +static inline int wkup_m3_prepare_low_power(int state) { return -1; } +static inline int wkup_m3_finish_low_power(void) { return -1; } +static inline int wkup_m3_request_pm_status(void) { return -1; } +#endif /* CONFIG_WKUP_M3_IPC */ +#endif /* _LINUX_WKUP_M3_H */