cros_ec_proto.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * ChromeOS Embedded Controller protocol interface.
  4 *
  5 * Copyright (C) 2012 Google, Inc
  6 */
  7
  8#ifndef __LINUX_CROS_EC_PROTO_H
  9#define __LINUX_CROS_EC_PROTO_H
 10
 11#include <linux/device.h>
 12#include <linux/lockdep_types.h>
 13#include <linux/mutex.h>
 14#include <linux/notifier.h>
 15
 16#include <linux/platform_data/cros_ec_commands.h>
 17
 18#define CROS_EC_DEV_NAME	"cros_ec"
 19#define CROS_EC_DEV_FP_NAME	"cros_fp"
 20#define CROS_EC_DEV_ISH_NAME	"cros_ish"
 21#define CROS_EC_DEV_PD_NAME	"cros_pd"
 22#define CROS_EC_DEV_SCP_NAME	"cros_scp"
 23#define CROS_EC_DEV_TP_NAME	"cros_tp"
 24
 25#define CROS_EC_DEV_EC_INDEX 0
 26#define CROS_EC_DEV_PD_INDEX 1
 27
 28/*
 29 * The EC is unresponsive for a time after a reboot command.  Add a
 30 * simple delay to make sure that the bus stays locked.
 31 */
 32#define EC_REBOOT_DELAY_MS		50
 33
 34/*
 35 * Max bus-specific overhead incurred by request/responses.
 36 *
 37 * Request:
 38 * - I2C requires 1 byte (see struct ec_host_request_i2c).
 39 * - ISHTP requires 4 bytes (see struct cros_ish_out_msg).
 40 *
 41 * Response:
 42 * - I2C requires 2 bytes (see struct ec_host_response_i2c).
 43 * - ISHTP requires 4 bytes (see struct cros_ish_in_msg).
 44 * - SPI requires 32 bytes (see EC_MSG_PREAMBLE_COUNT).
 45 */
 46#define EC_PROTO_VERSION_UNKNOWN	0
 47#define EC_MAX_REQUEST_OVERHEAD		4
 48#define EC_MAX_RESPONSE_OVERHEAD	32
 49
 50/*
 51 * ACPI notify value for MKBP host event.
 52 */
 53#define ACPI_NOTIFY_CROS_EC_MKBP 0x80
 54
 55/*
 56 * EC panic is not covered by the standard (0-F) ACPI notify values.
 57 * Arbitrarily choosing B0 to notify ec panic, which is in the 84-BF
 58 * device specific ACPI notify range.
 59 */
 60#define ACPI_NOTIFY_CROS_EC_PANIC 0xB0
 61
 62/*
 63 * Command interface between EC and AP, for LPC, I2C and SPI interfaces.
 64 */
 65enum {
 66	EC_MSG_TX_HEADER_BYTES	= 3,
 67	EC_MSG_TX_TRAILER_BYTES	= 1,
 68	EC_MSG_TX_PROTO_BYTES	= EC_MSG_TX_HEADER_BYTES +
 69				  EC_MSG_TX_TRAILER_BYTES,
 70	EC_MSG_RX_PROTO_BYTES	= 3,
 71
 72	/* Max length of messages for proto 2*/
 73	EC_PROTO2_MSG_BYTES	= EC_PROTO2_MAX_PARAM_SIZE +
 74				  EC_MSG_TX_PROTO_BYTES,
 75
 76	EC_MAX_MSG_BYTES	= 64 * 1024,
 77};
 78
 79/**
 80 * struct cros_ec_command - Information about a ChromeOS EC command.
 81 * @version: Command version number (often 0).
 82 * @command: Command to send (EC_CMD_...).
 83 * @outsize: Outgoing length in bytes.
 84 * @insize: Max number of bytes to accept from the EC.
 85 * @result: EC's response to the command (separate from communication failure).
 86 * @data: Where to put the incoming data from EC and outgoing data to EC.
 87 */
 88struct cros_ec_command {
 89	uint32_t version;
 90	uint32_t command;
 91	uint32_t outsize;
 92	uint32_t insize;
 93	uint32_t result;
 94	uint8_t data[];
 95};
 96
 97/**
 98 * struct cros_ec_device - Information about a ChromeOS EC device.
 99 * @phys_name: Name of physical comms layer (e.g. 'i2c-4').
100 * @dev: Device pointer for physical comms device
101 * @cros_class: The class structure for this device.
102 * @cmd_readmem: Direct read of the EC memory-mapped region, if supported.
103 *     @offset: Is within EC_LPC_ADDR_MEMMAP region.
104 *     @bytes: Number of bytes to read. zero means "read a string" (including
105 *             the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be
106 *             read. Caller must ensure that the buffer is large enough for the
107 *             result when reading a string.
108 * @max_request: Max size of message requested.
109 * @max_response: Max size of message response.
110 * @max_passthru: Max sice of passthru message.
111 * @proto_version: The protocol version used for this device.
112 * @priv: Private data.
113 * @irq: Interrupt to use.
114 * @id: Device id.
115 * @din: Input buffer (for data from EC). This buffer will always be
116 *       dword-aligned and include enough space for up to 7 word-alignment
117 *       bytes also, so we can ensure that the body of the message is always
118 *       dword-aligned (64-bit). We use this alignment to keep ARM and x86
119 *       happy. Probably word alignment would be OK, there might be a small
120 *       performance advantage to using dword.
121 * @dout: Output buffer (for data to EC). This buffer will always be
122 *        dword-aligned and include enough space for up to 7 word-alignment
123 *        bytes also, so we can ensure that the body of the message is always
124 *        dword-aligned (64-bit). We use this alignment to keep ARM and x86
125 *        happy. Probably word alignment would be OK, there might be a small
126 *        performance advantage to using dword.
127 * @din_size: Size of din buffer to allocate (zero to use static din).
128 * @dout_size: Size of dout buffer to allocate (zero to use static dout).
129 * @wake_enabled: True if this device can wake the system from sleep.
130 * @suspended: True if this device had been suspended.
131 * @registered: True if this device had been registered.
132 * @cmd_xfer: Send command to EC and get response.
133 *            Returns the number of bytes received if the communication
134 *            succeeded, but that doesn't mean the EC was happy with the
135 *            command. The caller should check msg.result for the EC's result
136 *            code.
137 * @pkt_xfer: Send packet to EC and get response.
138 * @lockdep_key: Lockdep class for each instance. Unused if CONFIG_LOCKDEP is
139 *		 not enabled.
140 * @lock: One transaction at a time.
141 * @mkbp_event_supported: 0 if MKBP not supported. Otherwise its value is
142 *                        the maximum supported version of the MKBP host event
143 *                        command + 1.
144 * @host_sleep_v1: True if this EC supports the sleep v1 command.
145 * @event_notifier: Interrupt event notifier for transport devices.
146 * @event_data: Raw payload transferred with the MKBP event.
147 * @event_size: Size in bytes of the event data.
148 * @host_event_wake_mask: Mask of host events that cause wake from suspend.
149 * @suspend_timeout_ms: The timeout in milliseconds between when sleep event
150 *                      is received and when the EC will declare sleep
151 *                      transition failure if the sleep signal is not
152 *                      asserted.  See also struct
153 *                      ec_params_host_sleep_event_v1 in cros_ec_commands.h.
154 * @last_resume_result: The number of sleep power signal transitions that
155 *                      occurred since the suspend message. The high bit
156 *                      indicates a timeout occurred.  See also struct
157 *                      ec_response_host_sleep_event_v1 in cros_ec_commands.h.
158 * @last_event_time: exact time from the hard irq when we got notified of
159 *     a new event.
160 * @notifier_ready: The notifier_block to let the kernel re-query EC
161 *		    communication protocol when the EC sends
162 *		    EC_HOST_EVENT_INTERFACE_READY.
163 * @ec: The platform_device used by the mfd driver to interface with the
164 *      main EC.
165 * @pd: The platform_device used by the mfd driver to interface with the
166 *      PD behind an EC.
167 * @panic_notifier: EC panic notifier.
168 */
169struct cros_ec_device {
170	/* These are used by other drivers that want to talk to the EC */
171	const char *phys_name;
172	struct device *dev;
173	struct class *cros_class;
174	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
175			   unsigned int bytes, void *dest);
176
177	/* These are used to implement the platform-specific interface */
178	u16 max_request;
179	u16 max_response;
180	u16 max_passthru;
181	u16 proto_version;
182	void *priv;
183	int irq;
184	u8 *din;
185	u8 *dout;
186	int din_size;
187	int dout_size;
188	bool wake_enabled;
189	bool suspended;
190	bool registered;
191	int (*cmd_xfer)(struct cros_ec_device *ec,
192			struct cros_ec_command *msg);
193	int (*pkt_xfer)(struct cros_ec_device *ec,
194			struct cros_ec_command *msg);
195	struct lock_class_key lockdep_key;
196	struct mutex lock;
197	u8 mkbp_event_supported;
198	bool host_sleep_v1;
199	struct blocking_notifier_head event_notifier;
200
201	struct ec_response_get_next_event_v3 event_data;
202	int event_size;
203	u32 host_event_wake_mask;
204	u32 last_resume_result;
205	u16 suspend_timeout_ms;
206	ktime_t last_event_time;
207	struct notifier_block notifier_ready;
208
209	/* The platform devices used by the mfd driver */
210	struct platform_device *ec;
211	struct platform_device *pd;
212
213	struct blocking_notifier_head panic_notifier;
214};
215
216/**
217 * struct cros_ec_platform - ChromeOS EC platform information.
218 * @ec_name: Name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
219 *           used in /dev/ and sysfs.
220 * @cmd_offset: Offset to apply for each command. Set when
221 *              registering a device behind another one.
222 */
223struct cros_ec_platform {
224	const char *ec_name;
225	u16 cmd_offset;
226};
227
228/**
229 * struct cros_ec_dev - ChromeOS EC device entry point.
230 * @class_dev: Device structure used in sysfs.
231 * @ec_dev: cros_ec_device structure to talk to the physical device.
232 * @dev: Pointer to the platform device.
233 * @debug_info: cros_ec_debugfs structure for debugging information.
234 * @has_kb_wake_angle: True if at least 2 accelerometer are connected to the EC.
235 * @cmd_offset: Offset to apply for each command.
236 * @features: Features supported by the EC.
237 */
238struct cros_ec_dev {
239	struct device class_dev;
240	struct cros_ec_device *ec_dev;
241	struct device *dev;
242	struct cros_ec_debugfs *debug_info;
243	bool has_kb_wake_angle;
244	u16 cmd_offset;
245	struct ec_response_get_features features;
246};
247
248#define to_cros_ec_dev(dev)  container_of(dev, struct cros_ec_dev, class_dev)
249
250int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
251		       struct cros_ec_command *msg);
252
253int cros_ec_check_result(struct cros_ec_device *ec_dev,
254			 struct cros_ec_command *msg);
255
256int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
257		     struct cros_ec_command *msg);
258
259int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
260			    struct cros_ec_command *msg);
261
262int cros_ec_rwsig_continue(struct cros_ec_device *ec_dev);
263
264int cros_ec_query_all(struct cros_ec_device *ec_dev);
265
266int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
267			   bool *wake_event,
268			   bool *has_more_events);
269
270u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
271
272bool cros_ec_check_features(struct cros_ec_dev *ec, int feature);
273
274int cros_ec_get_sensor_count(struct cros_ec_dev *ec);
275
276int cros_ec_cmd(struct cros_ec_device *ec_dev, unsigned int version, int command, const void *outdata,
277		    size_t outsize, void *indata, size_t insize);
278
279int cros_ec_cmd_readmem(struct cros_ec_device *ec_dev, u8 offset, u8 size, void *dest);
280
281int cros_ec_get_cmd_versions(struct cros_ec_device *ec_dev, u16 cmd);
282
283bool cros_ec_device_registered(struct cros_ec_device *ec_dev);
284
285/**
286 * cros_ec_get_time_ns() - Return time in ns.
287 *
288 * This is the function used to record the time for last_event_time in struct
289 * cros_ec_device during the hard irq.
290 *
291 * Return: ktime_t format since boot.
292 */
293static inline ktime_t cros_ec_get_time_ns(void)
294{
295	return ktime_get_boottime_ns();
296}
297
298#endif /* __LINUX_CROS_EC_PROTO_H */