This implements a driver that exposes the IPC bits found in the APCS Global block in various Qualcomm platforms. The bits are used to signal inter-processor communication signals from the application CPU to other masters. The driver implements the "doorbell" binding and could be used as basis for a new Linux framework, if found useful outside Qualcomm. Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx> --- Changes since v2: - New driver drivers/soc/qcom/Kconfig | 8 ++ drivers/soc/qcom/Makefile | 1 + drivers/soc/qcom/apcs-ipc.c | 182 ++++++++++++++++++++++++++++++++++++++ include/linux/soc/qcom/apcs_ipc.h | 26 ++++++ 4 files changed, 217 insertions(+) create mode 100644 drivers/soc/qcom/apcs-ipc.c create mode 100644 include/linux/soc/qcom/apcs_ipc.h diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig index 78b1bb7bcf20..4113da81d18b 100644 --- a/drivers/soc/qcom/Kconfig +++ b/drivers/soc/qcom/Kconfig @@ -1,6 +1,14 @@ # # QCOM Soc drivers # +config QCOM_APCS_IPC + tristate "Qualcomm APCS IPC driver" + depends on ARCH_QCOM + help + Say y here to enable support for the APCS IPC doorbell driver, + providing an interface for invoking the inter-process communication + signals from the application processor to other masters. + config QCOM_GSBI tristate "QCOM General Serial Bus Interface" depends on ARCH_QCOM diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile index 1f30260b06b8..e15b33e5a630 100644 --- a/drivers/soc/qcom/Makefile +++ b/drivers/soc/qcom/Makefile @@ -1,3 +1,4 @@ +obj-$(CONFIG_QCOM_APCS_IPC) += apcs-ipc.o obj-$(CONFIG_QCOM_GSBI) += qcom_gsbi.o obj-$(CONFIG_QCOM_MDT_LOADER) += mdt_loader.o obj-$(CONFIG_QCOM_PM) += spm.o diff --git a/drivers/soc/qcom/apcs-ipc.c b/drivers/soc/qcom/apcs-ipc.c new file mode 100644 index 000000000000..ea835cb08657 --- /dev/null +++ b/drivers/soc/qcom/apcs-ipc.c @@ -0,0 +1,182 @@ +/* + * Copyright (c) 2017, Linaro Ltd + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only 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/kernel.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/slab.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> + +static struct platform_driver qcom_apcs_ipc_driver; + +struct qcom_apcs_ipc { + struct device *dev; + + void __iomem *base; + unsigned long offset; +}; + +struct qcom_apcs_ipc_bell { + struct qcom_apcs_ipc *apcs; + unsigned int bit; +}; + +static void qcom_apcs_ipc_release(struct device *dev, void *res) +{ + struct qcom_apcs_ipc_bell *bell = res; + struct qcom_apcs_ipc *apcs = bell->apcs; + + put_device(apcs->dev); +} + +/** + * qcom_apcs_ipc_get() - acquire a handle to a doorbell + * @dev: client device handle + * @id: identifier of the doorbell + * + * Returns a doorbell reference, or negative errno on failure. + */ +struct qcom_apcs_ipc_bell *devm_qcom_apcs_ipc_get(struct device *dev, + const char *id) +{ + struct qcom_apcs_ipc_bell *bell; + struct platform_device *pdev; + struct of_phandle_args args; + int index = 0; + int ret; + + if (id) { + index = of_property_match_string(dev->of_node, + "doorbell-names", id); + if (index < 0) + return ERR_PTR(index); + } + + ret = of_parse_phandle_with_args(dev->of_node, "doorbells", + "#doorbell-cells", index, &args); + if (ret) { + dev_err(dev, "unable to resolve doorbell\n"); + return ERR_PTR(-ENODEV); + } + + pdev = of_find_device_by_node(args.np); + of_node_put(args.np); + + if (!pdev) + return ERR_PTR(-EPROBE_DEFER); + + if (args.args[0] >= 32) { + dev_err(dev, "invalid doorbell requested\n"); + ret = -EINVAL; + goto release_device; + } + + if (pdev->dev.driver != &qcom_apcs_ipc_driver.driver) { + dev_err(dev, "failed to acquire apcs ipc driver\n"); + ret = -EINVAL; + goto release_device; + } + + bell = devres_alloc(qcom_apcs_ipc_release, sizeof(*bell), GFP_KERNEL); + if (!bell) { + ret = -ENOMEM; + goto release_device; + } + + bell->apcs = platform_get_drvdata(pdev); + bell->bit = args.args[0]; + + devres_add(dev, bell); + + return bell; + +release_device: + put_device(&pdev->dev); + + return ERR_PTR(ret); + +} +EXPORT_SYMBOL_GPL(devm_qcom_apcs_ipc_get); + +/** + * qcom_apcs_ipc_ring() - ring the doorbell + * @bell: doorbell to ring + */ +void qcom_apcs_ipc_ring(struct qcom_apcs_ipc_bell *bell) +{ + struct qcom_apcs_ipc *apcs = bell->apcs; + + writel(BIT(bell->bit), apcs->base + apcs->offset); +} +EXPORT_SYMBOL_GPL(qcom_apcs_ipc_ring); + +static int qcom_apcs_ipc_probe(struct platform_device *pdev) +{ + struct qcom_apcs_ipc *apcs; + struct resource *res; + + apcs = devm_kzalloc(&pdev->dev, sizeof(*apcs), GFP_KERNEL); + if (!apcs) + return -ENOMEM; + + apcs->dev = &pdev->dev; + apcs->offset = (unsigned long)of_device_get_match_data(&pdev->dev); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + apcs->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(apcs->base)) + return PTR_ERR(apcs->base); + + platform_set_drvdata(pdev, apcs); + + return 0; +} + +static int qcom_apcs_ipc_remove(struct platform_device *pdev) +{ + return 0; +} + +/* .data is the offset of the ipc register within the global block */ +static const struct of_device_id qcom_apcs_ipc_of_match[] = { + { .compatible = "qcom,msm8916-apcs-kpss-global", .data = (void *)8 }, + { .compatible = "qcom,msm8996-apcs-hmss-global", .data = (void *)16 }, + {} +}; +MODULE_DEVICE_TABLE(of, qcom_apcs_ipc_of_match); + +static struct platform_driver qcom_apcs_ipc_driver = { + .probe = qcom_apcs_ipc_probe, + .remove = qcom_apcs_ipc_remove, + .driver = { + .name = "qcom_apcs_ipc", + .of_match_table = qcom_apcs_ipc_of_match, + }, +}; + +static int __init qcom_apcs_ipc_init(void) +{ + return platform_driver_register(&qcom_apcs_ipc_driver); +} +postcore_initcall(qcom_apcs_ipc_init); + +static void __exit qcom_apcs_ipc_exit(void) +{ + platform_driver_unregister(&qcom_apcs_ipc_driver); +} +module_exit(qcom_apcs_ipc_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Qualcomm APCS IPC driver"); diff --git a/include/linux/soc/qcom/apcs_ipc.h b/include/linux/soc/qcom/apcs_ipc.h new file mode 100644 index 000000000000..72be77555261 --- /dev/null +++ b/include/linux/soc/qcom/apcs_ipc.h @@ -0,0 +1,26 @@ +#ifndef __QCOM_APCS_IPC_H__ +#define __QCOM_APCS_IPC_H__ + +#include <linux/err.h> + +struct device; +struct qcom_apcs_ipc_bell; + +#if IS_ENABLED(CONFIG_QCOM_APCS_IPC) + +struct qcom_apcs_ipc_bell *devm_qcom_apcs_ipc_get(struct device *dev, + const char *id); +void qcom_apcs_ipc_ring(struct qcom_apcs_ipc_bell *bell); + +#else + +static inline struct qcom_apcs_ipc_bell *devm_qcom_apcs_ipc_get(struct device *dev, + const char *id) +{ + return ERR_PTR(-EINVAL); +} + +static inline void qcom_apcs_ipc_ring(struct qcom_apcs_ipc_bell *bell) {} + +#endif +#endif -- 2.12.0 -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html