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	rtc: optee: add RTC driver for OP-TEE RTC PTA
This drivers allows to communicate with a RTC PTA handled by OP-TEE [1]. This PTA allows to query RTC information, set/get time and set/get offset depending on the supported features. [1] https://github.com/OP-TEE/optee_os/pull/5179 Signed-off-by: Clément Léger <clement.leger@bootlin.com> Reviewed-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20220308133505.471601-1-clement.leger@bootlin.com
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		|  | @ -14356,6 +14356,12 @@ L:	op-tee@lists.trustedfirmware.org | |||
| S:	Maintained | ||||
| F:	drivers/char/hw_random/optee-rng.c | ||||
| 
 | ||||
| OP-TEE RTC DRIVER | ||||
| M:	Clément Léger <clement.leger@bootlin.com> | ||||
| L:	linux-rtc@vger.kernel.org | ||||
| S:	Maintained | ||||
| F:	drivers/rtc/rtc-optee.c | ||||
| 
 | ||||
| OPA-VNIC DRIVER | ||||
| M:	Dennis Dalessandro <dennis.dalessandro@cornelisnetworks.com> | ||||
| M:	Mike Marciniszyn <mike.marciniszyn@cornelisnetworks.com> | ||||
|  |  | |||
|  | @ -1293,6 +1293,16 @@ config RTC_DRV_OPAL | |||
| 	  This driver can also be built as a module. If so, the module | ||||
| 	  will be called rtc-opal. | ||||
| 
 | ||||
| config RTC_DRV_OPTEE | ||||
| 	tristate "OP-TEE based RTC driver" | ||||
| 	depends on OPTEE | ||||
| 	help | ||||
| 	  Select this to get support for OP-TEE based RTC control on SoCs where | ||||
| 	  RTC are not accessible to the normal world (Linux). | ||||
| 
 | ||||
| 	  This driver can also be built as a module. If so, the module | ||||
| 	  will be called rtc-optee. | ||||
| 
 | ||||
| config RTC_DRV_ZYNQMP | ||||
| 	tristate "Xilinx Zynq Ultrascale+ MPSoC RTC" | ||||
| 	depends on OF && HAS_IOMEM | ||||
|  |  | |||
|  | @ -115,6 +115,7 @@ obj-$(CONFIG_RTC_DRV_GAMECUBE)	+= rtc-gamecube.o | |||
| obj-$(CONFIG_RTC_DRV_NTXEC)	+= rtc-ntxec.o | ||||
| obj-$(CONFIG_RTC_DRV_OMAP)	+= rtc-omap.o | ||||
| obj-$(CONFIG_RTC_DRV_OPAL)	+= rtc-opal.o | ||||
| obj-$(CONFIG_RTC_DRV_OPTEE)	+= rtc-optee.o | ||||
| obj-$(CONFIG_RTC_DRV_PALMAS)	+= rtc-palmas.o | ||||
| obj-$(CONFIG_RTC_DRV_PCAP)	+= rtc-pcap.o | ||||
| obj-$(CONFIG_RTC_DRV_PCF2123)	+= rtc-pcf2123.o | ||||
|  |  | |||
							
								
								
									
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								drivers/rtc/rtc-optee.c
									
									
									
									
									
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								drivers/rtc/rtc-optee.c
									
									
									
									
									
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							|  | @ -0,0 +1,362 @@ | |||
| // SPDX-License-Identifier: GPL-2.0
 | ||||
| /*
 | ||||
|  * Copyright (C) 2022 Microchip. | ||||
|  */ | ||||
| 
 | ||||
| #include <linux/device.h> | ||||
| #include <linux/kernel.h> | ||||
| #include <linux/module.h> | ||||
| #include <linux/rtc.h> | ||||
| #include <linux/tee_drv.h> | ||||
| 
 | ||||
| #define RTC_INFO_VERSION	0x1 | ||||
| 
 | ||||
| #define TA_CMD_RTC_GET_INFO		0x0 | ||||
| #define TA_CMD_RTC_GET_TIME		0x1 | ||||
| #define TA_CMD_RTC_SET_TIME		0x2 | ||||
| #define TA_CMD_RTC_GET_OFFSET		0x3 | ||||
| #define TA_CMD_RTC_SET_OFFSET		0x4 | ||||
| 
 | ||||
| #define TA_RTC_FEATURE_CORRECTION	BIT(0) | ||||
| 
 | ||||
| struct optee_rtc_time { | ||||
| 	u32 tm_sec; | ||||
| 	u32 tm_min; | ||||
| 	u32 tm_hour; | ||||
| 	u32 tm_mday; | ||||
| 	u32 tm_mon; | ||||
| 	u32 tm_year; | ||||
| 	u32 tm_wday; | ||||
| }; | ||||
| 
 | ||||
| struct optee_rtc_info { | ||||
| 	u64 version; | ||||
| 	u64 features; | ||||
| 	struct optee_rtc_time range_min; | ||||
| 	struct optee_rtc_time range_max; | ||||
| }; | ||||
| 
 | ||||
| /**
 | ||||
|  * struct optee_rtc - OP-TEE RTC private data | ||||
|  * @dev:		OP-TEE based RTC device. | ||||
|  * @ctx:		OP-TEE context handler. | ||||
|  * @session_id:		RTC TA session identifier. | ||||
|  * @shm:		Memory pool shared with RTC device. | ||||
|  * @features:		Bitfield of RTC features | ||||
|  */ | ||||
| struct optee_rtc { | ||||
| 	struct device *dev; | ||||
| 	struct tee_context *ctx; | ||||
| 	u32 session_id; | ||||
| 	struct tee_shm *shm; | ||||
| 	u64 features; | ||||
| }; | ||||
| 
 | ||||
| static int optee_rtc_readtime(struct device *dev, struct rtc_time *tm) | ||||
| { | ||||
| 	struct optee_rtc *priv = dev_get_drvdata(dev); | ||||
| 	struct tee_ioctl_invoke_arg inv_arg = {0}; | ||||
| 	struct optee_rtc_time *optee_tm; | ||||
| 	struct tee_param param[4] = {0}; | ||||
| 	int ret; | ||||
| 
 | ||||
| 	inv_arg.func = TA_CMD_RTC_GET_TIME; | ||||
| 	inv_arg.session = priv->session_id; | ||||
| 	inv_arg.num_params = 4; | ||||
| 
 | ||||
| 	/* Fill invoke cmd params */ | ||||
| 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; | ||||
| 	param[0].u.memref.shm = priv->shm; | ||||
| 	param[0].u.memref.size = sizeof(struct optee_rtc_time); | ||||
| 
 | ||||
| 	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param); | ||||
| 	if (ret < 0 || inv_arg.ret != 0) | ||||
| 		return ret ? ret : -EPROTO; | ||||
| 
 | ||||
| 	optee_tm = tee_shm_get_va(priv->shm, 0); | ||||
| 	if (IS_ERR(optee_tm)) | ||||
| 		return PTR_ERR(optee_tm); | ||||
| 
 | ||||
| 	if (param[0].u.memref.size != sizeof(*optee_tm)) | ||||
| 		return -EPROTO; | ||||
| 
 | ||||
| 	tm->tm_sec = optee_tm->tm_sec; | ||||
| 	tm->tm_min = optee_tm->tm_min; | ||||
| 	tm->tm_hour = optee_tm->tm_hour; | ||||
| 	tm->tm_mday = optee_tm->tm_mday; | ||||
| 	tm->tm_mon = optee_tm->tm_mon; | ||||
| 	tm->tm_year = optee_tm->tm_year - 1900; | ||||
| 	tm->tm_wday = optee_tm->tm_wday; | ||||
| 	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year); | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static int optee_rtc_settime(struct device *dev, struct rtc_time *tm) | ||||
| { | ||||
| 	struct optee_rtc *priv = dev_get_drvdata(dev); | ||||
| 	struct tee_ioctl_invoke_arg inv_arg = {0}; | ||||
| 	struct tee_param param[4] = {0}; | ||||
| 	struct optee_rtc_time optee_tm; | ||||
| 	void *rtc_data; | ||||
| 	int ret; | ||||
| 
 | ||||
| 	optee_tm.tm_sec = tm->tm_sec; | ||||
| 	optee_tm.tm_min = tm->tm_min; | ||||
| 	optee_tm.tm_hour = tm->tm_hour; | ||||
| 	optee_tm.tm_mday = tm->tm_mday; | ||||
| 	optee_tm.tm_mon = tm->tm_mon; | ||||
| 	optee_tm.tm_year = tm->tm_year + 1900; | ||||
| 	optee_tm.tm_wday = tm->tm_wday; | ||||
| 
 | ||||
| 	inv_arg.func = TA_CMD_RTC_SET_TIME; | ||||
| 	inv_arg.session = priv->session_id; | ||||
| 	inv_arg.num_params = 4; | ||||
| 
 | ||||
| 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT; | ||||
| 	param[0].u.memref.shm = priv->shm; | ||||
| 	param[0].u.memref.size = sizeof(struct optee_rtc_time); | ||||
| 
 | ||||
| 	rtc_data = tee_shm_get_va(priv->shm, 0); | ||||
| 	if (IS_ERR(rtc_data)) | ||||
| 		return PTR_ERR(rtc_data); | ||||
| 
 | ||||
| 	memcpy(rtc_data, &optee_tm, sizeof(struct optee_rtc_time)); | ||||
| 
 | ||||
| 	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param); | ||||
| 	if (ret < 0 || inv_arg.ret != 0) | ||||
| 		return ret ? ret : -EPROTO; | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static int optee_rtc_readoffset(struct device *dev, long *offset) | ||||
| { | ||||
| 	struct optee_rtc *priv = dev_get_drvdata(dev); | ||||
| 	struct tee_ioctl_invoke_arg inv_arg = {0}; | ||||
| 	struct tee_param param[4] = {0}; | ||||
| 	int ret; | ||||
| 
 | ||||
| 	if (!(priv->features & TA_RTC_FEATURE_CORRECTION)) | ||||
| 		return -EOPNOTSUPP; | ||||
| 
 | ||||
| 	inv_arg.func = TA_CMD_RTC_GET_OFFSET; | ||||
| 	inv_arg.session = priv->session_id; | ||||
| 	inv_arg.num_params = 4; | ||||
| 
 | ||||
| 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT; | ||||
| 
 | ||||
| 	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param); | ||||
| 	if (ret < 0 || inv_arg.ret != 0) | ||||
| 		return ret ? ret : -EPROTO; | ||||
| 
 | ||||
| 	*offset = param[0].u.value.a; | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static int optee_rtc_setoffset(struct device *dev, long offset) | ||||
| { | ||||
| 	struct optee_rtc *priv = dev_get_drvdata(dev); | ||||
| 	struct tee_ioctl_invoke_arg inv_arg = {0}; | ||||
| 	struct tee_param param[4] = {0}; | ||||
| 	int ret; | ||||
| 
 | ||||
| 	if (!(priv->features & TA_RTC_FEATURE_CORRECTION)) | ||||
| 		return -EOPNOTSUPP; | ||||
| 
 | ||||
| 	inv_arg.func = TA_CMD_RTC_SET_OFFSET; | ||||
| 	inv_arg.session = priv->session_id; | ||||
| 	inv_arg.num_params = 4; | ||||
| 
 | ||||
| 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT; | ||||
| 	param[0].u.value.a = offset; | ||||
| 
 | ||||
| 	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param); | ||||
| 	if (ret < 0 || inv_arg.ret != 0) | ||||
| 		return ret ? ret : -EPROTO; | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static const struct rtc_class_ops optee_rtc_ops = { | ||||
| 	.read_time	= optee_rtc_readtime, | ||||
| 	.set_time	= optee_rtc_settime, | ||||
| 	.set_offset	= optee_rtc_setoffset, | ||||
| 	.read_offset	= optee_rtc_readoffset, | ||||
| }; | ||||
| 
 | ||||
| static int optee_rtc_read_info(struct device *dev, struct rtc_device *rtc, | ||||
| 			       u64 *features) | ||||
| { | ||||
| 	struct optee_rtc *priv = dev_get_drvdata(dev); | ||||
| 	struct tee_ioctl_invoke_arg inv_arg = {0}; | ||||
| 	struct tee_param param[4] = {0}; | ||||
| 	struct optee_rtc_info *info; | ||||
| 	struct optee_rtc_time *tm; | ||||
| 	int ret; | ||||
| 
 | ||||
| 	inv_arg.func = TA_CMD_RTC_GET_INFO; | ||||
| 	inv_arg.session = priv->session_id; | ||||
| 	inv_arg.num_params = 4; | ||||
| 
 | ||||
| 	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT; | ||||
| 	param[0].u.memref.shm = priv->shm; | ||||
| 	param[0].u.memref.size = sizeof(*info); | ||||
| 
 | ||||
| 	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param); | ||||
| 	if (ret < 0 || inv_arg.ret != 0) | ||||
| 		return ret ? ret : -EPROTO; | ||||
| 
 | ||||
| 	info = tee_shm_get_va(priv->shm, 0); | ||||
| 	if (IS_ERR(info)) | ||||
| 		return PTR_ERR(info); | ||||
| 
 | ||||
| 	if (param[0].u.memref.size != sizeof(*info)) | ||||
| 		return -EPROTO; | ||||
| 
 | ||||
| 	if (info->version != RTC_INFO_VERSION) | ||||
| 		return -EPROTO; | ||||
| 
 | ||||
| 	*features = info->features; | ||||
| 
 | ||||
| 	tm = &info->range_min; | ||||
| 	rtc->range_min = mktime64(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, | ||||
| 				  tm->tm_sec); | ||||
| 	tm = &info->range_max; | ||||
| 	rtc->range_max = mktime64(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, | ||||
| 				  tm->tm_sec); | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) | ||||
| { | ||||
| 	if (ver->impl_id == TEE_IMPL_ID_OPTEE) | ||||
| 		return 1; | ||||
| 	else | ||||
| 		return 0; | ||||
| } | ||||
| 
 | ||||
| static int optee_rtc_probe(struct device *dev) | ||||
| { | ||||
| 	struct tee_client_device *rtc_device = to_tee_client_device(dev); | ||||
| 	struct tee_ioctl_open_session_arg sess_arg; | ||||
| 	struct optee_rtc *priv; | ||||
| 	struct rtc_device *rtc; | ||||
| 	struct tee_shm *shm; | ||||
| 	int ret, err; | ||||
| 
 | ||||
| 	memset(&sess_arg, 0, sizeof(sess_arg)); | ||||
| 
 | ||||
| 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); | ||||
| 	if (!priv) | ||||
| 		return -ENOMEM; | ||||
| 
 | ||||
| 	rtc = devm_rtc_allocate_device(dev); | ||||
| 	if (IS_ERR(rtc)) | ||||
| 		return PTR_ERR(rtc); | ||||
| 
 | ||||
| 	/* Open context with TEE driver */ | ||||
| 	priv->ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL); | ||||
| 	if (IS_ERR(priv->ctx)) | ||||
| 		return -ENODEV; | ||||
| 
 | ||||
| 	/* Open session with rtc Trusted App */ | ||||
| 	export_uuid(sess_arg.uuid, &rtc_device->id.uuid); | ||||
| 	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL; | ||||
| 
 | ||||
| 	ret = tee_client_open_session(priv->ctx, &sess_arg, NULL); | ||||
| 	if (ret < 0 || sess_arg.ret != 0) { | ||||
| 		dev_err(dev, "tee_client_open_session failed, err: %x\n", sess_arg.ret); | ||||
| 		err = -EINVAL; | ||||
| 		goto out_ctx; | ||||
| 	} | ||||
| 	priv->session_id = sess_arg.session; | ||||
| 
 | ||||
| 	shm = tee_shm_alloc_kernel_buf(priv->ctx, sizeof(struct optee_rtc_info)); | ||||
| 	if (IS_ERR(shm)) { | ||||
| 		dev_err(priv->dev, "tee_shm_alloc_kernel_buf failed\n"); | ||||
| 		err = PTR_ERR(shm); | ||||
| 		goto out_sess; | ||||
| 	} | ||||
| 
 | ||||
| 	priv->shm = shm; | ||||
| 	priv->dev = dev; | ||||
| 	dev_set_drvdata(dev, priv); | ||||
| 
 | ||||
| 	rtc->ops = &optee_rtc_ops; | ||||
| 
 | ||||
| 	err = optee_rtc_read_info(dev, rtc, &priv->features); | ||||
| 	if (err) { | ||||
| 		dev_err(dev, "Failed to get RTC features from OP-TEE\n"); | ||||
| 		goto out_shm; | ||||
| 	} | ||||
| 
 | ||||
| 	err = devm_rtc_register_device(rtc); | ||||
| 	if (err) | ||||
| 		goto out_shm; | ||||
| 
 | ||||
| 	/*
 | ||||
| 	 * We must clear this bit after registering because rtc_register_device | ||||
| 	 * will set it if it sees that .set_offset is provided. | ||||
| 	 */ | ||||
| 	if (!(priv->features & TA_RTC_FEATURE_CORRECTION)) | ||||
| 		clear_bit(RTC_FEATURE_CORRECTION, rtc->features); | ||||
| 
 | ||||
| 	return 0; | ||||
| 
 | ||||
| out_shm: | ||||
| 	tee_shm_free(priv->shm); | ||||
| out_sess: | ||||
| 	tee_client_close_session(priv->ctx, priv->session_id); | ||||
| out_ctx: | ||||
| 	tee_client_close_context(priv->ctx); | ||||
| 
 | ||||
| 	return err; | ||||
| } | ||||
| 
 | ||||
| static int optee_rtc_remove(struct device *dev) | ||||
| { | ||||
| 	struct optee_rtc *priv = dev_get_drvdata(dev); | ||||
| 
 | ||||
| 	tee_client_close_session(priv->ctx, priv->session_id); | ||||
| 	tee_client_close_context(priv->ctx); | ||||
| 
 | ||||
| 	return 0; | ||||
| } | ||||
| 
 | ||||
| static const struct tee_client_device_id optee_rtc_id_table[] = { | ||||
| 	{UUID_INIT(0xf389f8c8, 0x845f, 0x496c, | ||||
| 		   0x8b, 0xbe, 0xd6, 0x4b, 0xd2, 0x4c, 0x92, 0xfd)}, | ||||
| 	{} | ||||
| }; | ||||
| 
 | ||||
| MODULE_DEVICE_TABLE(tee, optee_rtc_id_table); | ||||
| 
 | ||||
| static struct tee_client_driver optee_rtc_driver = { | ||||
| 	.id_table	= optee_rtc_id_table, | ||||
| 	.driver		= { | ||||
| 		.name		= "optee_rtc", | ||||
| 		.bus		= &tee_bus_type, | ||||
| 		.probe		= optee_rtc_probe, | ||||
| 		.remove		= optee_rtc_remove, | ||||
| 	}, | ||||
| }; | ||||
| 
 | ||||
| static int __init optee_rtc_mod_init(void) | ||||
| { | ||||
| 	return driver_register(&optee_rtc_driver.driver); | ||||
| } | ||||
| 
 | ||||
| static void __exit optee_rtc_mod_exit(void) | ||||
| { | ||||
| 	driver_unregister(&optee_rtc_driver.driver); | ||||
| } | ||||
| 
 | ||||
| module_init(optee_rtc_mod_init); | ||||
| module_exit(optee_rtc_mod_exit); | ||||
| 
 | ||||
| MODULE_LICENSE("GPL v2"); | ||||
| MODULE_AUTHOR("Clément Léger <clement.leger@bootlin.com>"); | ||||
| MODULE_DESCRIPTION("OP-TEE based RTC driver"); | ||||
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	 Clément Léger
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