xref: /openbmc/linux/drivers/i2c/busses/i2c-amd-mp2.h (revision 7559e757)
1 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
2 /*
3  * AMD MP2 I2C adapter driver
4  *
5  * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
6  *          Elie Morisse <syniurge@gmail.com>
7  */
8 
9 #ifndef I2C_AMD_PCI_MP2_H
10 #define I2C_AMD_PCI_MP2_H
11 
12 #include <linux/i2c.h>
13 #include <linux/pci.h>
14 #include <linux/pm_runtime.h>
15 
16 #define PCI_DEVICE_ID_AMD_MP2	0x15E6
17 
18 struct amd_i2c_common;
19 struct amd_mp2_dev;
20 
21 enum {
22 	/* MP2 C2P Message Registers */
23 	AMD_C2P_MSG0 = 0x10500,			/* MP2 Message for I2C0 */
24 	AMD_C2P_MSG1 = 0x10504,			/* MP2 Message for I2C1 */
25 	AMD_C2P_MSG2 = 0x10508,			/* DRAM Address Lo / Data 0 */
26 	AMD_C2P_MSG3 = 0x1050c,			/* DRAM Address HI / Data 1 */
27 	AMD_C2P_MSG4 = 0x10510,			/* Data 2 */
28 	AMD_C2P_MSG5 = 0x10514,			/* Data 3 */
29 	AMD_C2P_MSG6 = 0x10518,			/* Data 4 */
30 	AMD_C2P_MSG7 = 0x1051c,			/* Data 5 */
31 	AMD_C2P_MSG8 = 0x10520,			/* Data 6 */
32 	AMD_C2P_MSG9 = 0x10524,			/* Data 7 */
33 
34 	/* MP2 P2C Message Registers */
35 	AMD_P2C_MSG0 = 0x10680,			/* Do not use */
36 	AMD_P2C_MSG1 = 0x10684,			/* I2C0 interrupt register */
37 	AMD_P2C_MSG2 = 0x10688,			/* I2C1 interrupt register */
38 	AMD_P2C_MSG3 = 0x1068C,			/* MP2 debug info */
39 	AMD_P2C_MSG_INTEN = 0x10690,		/* MP2 interrupt gen register */
40 	AMD_P2C_MSG_INTSTS = 0x10694,		/* Interrupt status */
41 };
42 
43 /* Command register data structures */
44 
45 #define i2c_none (-1)
46 enum i2c_cmd {
47 	i2c_read = 0,
48 	i2c_write,
49 	i2c_enable,
50 	i2c_disable,
51 	number_of_sensor_discovered,
52 	is_mp2_active,
53 	invalid_cmd = 0xF,
54 };
55 
56 enum speed_enum {
57 	speed100k = 0,
58 	speed400k = 1,
59 	speed1000k = 2,
60 	speed1400k = 3,
61 	speed3400k = 4
62 };
63 
64 enum mem_type {
65 	use_dram = 0,
66 	use_c2pmsg = 1,
67 };
68 
69 /**
70  * union i2c_cmd_base : bit access of C2P commands
71  * @i2c_cmd: bit 0..3 i2c R/W command
72  * @bus_id: bit 4..7 i2c bus index
73  * @slave_addr: bit 8..15 slave address
74  * @length: bit 16..27 read/write length
75  * @i2c_speed: bit 28..30 bus speed
76  * @mem_type: bit 31 0-DRAM; 1-C2P msg o/p
77  */
78 union i2c_cmd_base {
79 	u32 ul;
80 	struct {
81 		enum i2c_cmd i2c_cmd : 4;
82 		u8 bus_id : 4;
83 		u32 slave_addr : 8;
84 		u32 length : 12;
85 		enum speed_enum i2c_speed : 3;
86 		enum mem_type mem_type : 1;
87 	} s;
88 };
89 
90 enum response_type {
91 	invalid_response = 0,
92 	command_success = 1,
93 	command_failed = 2,
94 };
95 
96 enum status_type {
97 	i2c_readcomplete_event = 0,
98 	i2c_readfail_event = 1,
99 	i2c_writecomplete_event = 2,
100 	i2c_writefail_event = 3,
101 	i2c_busenable_complete = 4,
102 	i2c_busenable_failed = 5,
103 	i2c_busdisable_complete = 6,
104 	i2c_busdisable_failed = 7,
105 	invalid_data_length = 8,
106 	invalid_slave_address = 9,
107 	invalid_i2cbus_id = 10,
108 	invalid_dram_addr = 11,
109 	invalid_command = 12,
110 	mp2_active = 13,
111 	numberof_sensors_discovered_resp = 14,
112 	i2c_bus_notinitialized
113 };
114 
115 /**
116  * union i2c_event : bit access of P2C events
117  * @response: bit 0..1 i2c response type
118  * @status: bit 2..6 status_type
119  * @mem_type: bit 7 0-DRAM; 1-C2P msg o/p
120  * @bus_id: bit 8..11 i2c bus id
121  * @length: bit 12..23 message length
122  * @slave_addr: bit 24-31 slave address
123  */
124 union i2c_event {
125 	u32 ul;
126 	struct {
127 		enum response_type response : 2;
128 		enum status_type status : 5;
129 		enum mem_type mem_type : 1;
130 		u8 bus_id : 4;
131 		u32 length : 12;
132 		u32 slave_addr : 8;
133 	} r;
134 };
135 
136 /**
137  * struct amd_i2c_common - per bus/i2c adapter context, shared
138  *	between the pci and the platform driver
139  * @eventval: MP2 event value set by the IRQ handler
140  * @mp2_dev: MP2 pci device this adapter is part of
141  * @msg: i2c message
142  * @cmd_completion: function called by the IRQ handler to signal
143  *		    the platform driver
144  * @reqcmd: requested i2c command type
145  * @cmd_success: set to true if the MP2 responded to a command with
146  *		 the expected status and response type
147  * @bus_id: bus index
148  * @i2c_speed: i2c bus speed determined by the slowest slave
149  * @dma_buf: if msg length > 32, holds the DMA buffer virtual address
150  * @dma_addr: if msg length > 32, holds the DMA buffer address
151  */
152 struct amd_i2c_common {
153 	union i2c_event eventval;
154 	struct amd_mp2_dev *mp2_dev;
155 	struct i2c_msg *msg;
156 	void (*cmd_completion)(struct amd_i2c_common *i2c_common);
157 	enum i2c_cmd reqcmd;
158 	u8 cmd_success;
159 	u8 bus_id;
160 	enum speed_enum i2c_speed;
161 	u8 *dma_buf;
162 	dma_addr_t dma_addr;
163 #ifdef CONFIG_PM
164 	int (*suspend)(struct amd_i2c_common *i2c_common);
165 	int (*resume)(struct amd_i2c_common *i2c_common);
166 #endif /* CONFIG_PM */
167 };
168 
169 /**
170  * struct amd_mp2_dev - per PCI device context
171  * @pci_dev: PCI driver node
172  * @busses: MP2 devices may have up to two busses,
173  *	    each bus corresponding to an i2c adapter
174  * @mmio: iommapped registers
175  * @c2p_lock: controls access to the C2P mailbox shared between
176  *	      the two adapters
177  * @c2p_lock_busid: id of the adapter which locked c2p_lock
178  */
179 struct amd_mp2_dev {
180 	struct pci_dev *pci_dev;
181 	struct amd_i2c_common *busses[2];
182 	void __iomem *mmio;
183 	struct mutex c2p_lock;
184 	u8 c2p_lock_busid;
185 	unsigned int probed;
186 	int dev_irq;
187 };
188 
189 /* PCIe communication driver */
190 
191 int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd);
192 int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable);
193 
194 void amd_mp2_process_event(struct amd_i2c_common *i2c_common);
195 
196 void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common);
197 
198 int amd_mp2_register_cb(struct amd_i2c_common *i2c_common);
199 int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common);
200 
201 struct amd_mp2_dev *amd_mp2_find_device(void);
202 
203 static inline void amd_mp2_pm_runtime_get(struct amd_mp2_dev *mp2_dev)
204 {
205 	pm_runtime_get_sync(&mp2_dev->pci_dev->dev);
206 }
207 
208 static inline void amd_mp2_pm_runtime_put(struct amd_mp2_dev *mp2_dev)
209 {
210 	pm_runtime_mark_last_busy(&mp2_dev->pci_dev->dev);
211 	pm_runtime_put_autosuspend(&mp2_dev->pci_dev->dev);
212 }
213 
214 #endif
215