1 #include <linux/atomic.h>
2 #include <linux/clk.h>
3 #include <linux/delay.h>
4 #include <linux/device.h>
5 #include <linux/i2c.h>
6 #include <linux/i2c-smbus.h>
7 #include <linux/io.h>
8 #include <linux/iopoll.h>
9 #include <linux/kernel.h>
10 #include <linux/pci.h>
11 
12 /* Controller command patterns */
13 #define SW_TWSI_V		BIT_ULL(63)	/* Valid bit */
14 #define SW_TWSI_EIA		BIT_ULL(61)	/* Extended internal address */
15 #define SW_TWSI_R		BIT_ULL(56)	/* Result or read bit */
16 #define SW_TWSI_SOVR		BIT_ULL(55)	/* Size override */
17 #define SW_TWSI_SIZE_SHIFT	52
18 #define SW_TWSI_ADDR_SHIFT	40
19 #define SW_TWSI_IA_SHIFT	32		/* Internal address */
20 
21 /* Controller opcode word (bits 60:57) */
22 #define SW_TWSI_OP_SHIFT	57
23 #define SW_TWSI_OP_7		(0ULL << SW_TWSI_OP_SHIFT)
24 #define SW_TWSI_OP_7_IA		(1ULL << SW_TWSI_OP_SHIFT)
25 #define SW_TWSI_OP_10		(2ULL << SW_TWSI_OP_SHIFT)
26 #define SW_TWSI_OP_10_IA	(3ULL << SW_TWSI_OP_SHIFT)
27 #define SW_TWSI_OP_TWSI_CLK	(4ULL << SW_TWSI_OP_SHIFT)
28 #define SW_TWSI_OP_EOP		(6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
29 
30 /* Controller extended opcode word (bits 34:32) */
31 #define SW_TWSI_EOP_SHIFT	32
32 #define SW_TWSI_EOP_TWSI_DATA	(SW_TWSI_OP_EOP | 1ULL << SW_TWSI_EOP_SHIFT)
33 #define SW_TWSI_EOP_TWSI_CTL	(SW_TWSI_OP_EOP | 2ULL << SW_TWSI_EOP_SHIFT)
34 #define SW_TWSI_EOP_TWSI_CLKCTL	(SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
35 #define SW_TWSI_EOP_TWSI_STAT	(SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
36 #define SW_TWSI_EOP_TWSI_RST	(SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
37 
38 /* Controller command and status bits */
39 #define TWSI_CTL_CE		0x80	/* High level controller enable */
40 #define TWSI_CTL_ENAB		0x40	/* Bus enable */
41 #define TWSI_CTL_STA		0x20	/* Master-mode start, HW clears when done */
42 #define TWSI_CTL_STP		0x10	/* Master-mode stop, HW clears when done */
43 #define TWSI_CTL_IFLG		0x08	/* HW event, SW writes 0 to ACK */
44 #define TWSI_CTL_AAK		0x04	/* Assert ACK */
45 
46 /* Status values */
47 #define STAT_ERROR		0x00
48 #define STAT_START		0x08
49 #define STAT_REP_START		0x10
50 #define STAT_TXADDR_ACK		0x18
51 #define STAT_TXADDR_NAK		0x20
52 #define STAT_TXDATA_ACK		0x28
53 #define STAT_TXDATA_NAK		0x30
54 #define STAT_LOST_ARB_38	0x38
55 #define STAT_RXADDR_ACK		0x40
56 #define STAT_RXADDR_NAK		0x48
57 #define STAT_RXDATA_ACK		0x50
58 #define STAT_RXDATA_NAK		0x58
59 #define STAT_SLAVE_60		0x60
60 #define STAT_LOST_ARB_68	0x68
61 #define STAT_SLAVE_70		0x70
62 #define STAT_LOST_ARB_78	0x78
63 #define STAT_SLAVE_80		0x80
64 #define STAT_SLAVE_88		0x88
65 #define STAT_GENDATA_ACK	0x90
66 #define STAT_GENDATA_NAK	0x98
67 #define STAT_SLAVE_A0		0xA0
68 #define STAT_SLAVE_A8		0xA8
69 #define STAT_LOST_ARB_B0	0xB0
70 #define STAT_SLAVE_LOST		0xB8
71 #define STAT_SLAVE_NAK		0xC0
72 #define STAT_SLAVE_ACK		0xC8
73 #define STAT_AD2W_ACK		0xD0
74 #define STAT_AD2W_NAK		0xD8
75 #define STAT_IDLE		0xF8
76 
77 /* TWSI_INT values */
78 #define TWSI_INT_ST_INT		BIT_ULL(0)
79 #define TWSI_INT_TS_INT		BIT_ULL(1)
80 #define TWSI_INT_CORE_INT	BIT_ULL(2)
81 #define TWSI_INT_ST_EN		BIT_ULL(4)
82 #define TWSI_INT_TS_EN		BIT_ULL(5)
83 #define TWSI_INT_CORE_EN	BIT_ULL(6)
84 #define TWSI_INT_SDA_OVR	BIT_ULL(8)
85 #define TWSI_INT_SCL_OVR	BIT_ULL(9)
86 #define TWSI_INT_SDA		BIT_ULL(10)
87 #define TWSI_INT_SCL		BIT_ULL(11)
88 
89 #define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
90 
91 /* Register offsets */
92 struct octeon_i2c_reg_offset {
93 	unsigned int sw_twsi;
94 	unsigned int twsi_int;
95 	unsigned int sw_twsi_ext;
96 };
97 
98 #define SW_TWSI(x)	(x->roff.sw_twsi)
99 #define TWSI_INT(x)	(x->roff.twsi_int)
100 #define SW_TWSI_EXT(x)	(x->roff.sw_twsi_ext)
101 
102 struct octeon_i2c {
103 	wait_queue_head_t queue;
104 	struct i2c_adapter adap;
105 	struct octeon_i2c_reg_offset roff;
106 	struct clk *clk;
107 	int irq;
108 	int hlc_irq;		/* For cn7890 only */
109 	u32 twsi_freq;
110 	int sys_freq;
111 	void __iomem *twsi_base;
112 	struct device *dev;
113 	bool hlc_enabled;
114 	bool broken_irq_mode;
115 	bool broken_irq_check;
116 	void (*int_enable)(struct octeon_i2c *);
117 	void (*int_disable)(struct octeon_i2c *);
118 	void (*hlc_int_enable)(struct octeon_i2c *);
119 	void (*hlc_int_disable)(struct octeon_i2c *);
120 	atomic_t int_enable_cnt;
121 	atomic_t hlc_int_enable_cnt;
122 #if IS_ENABLED(CONFIG_I2C_THUNDERX)
123 	struct msix_entry i2c_msix;
124 #endif
125 	struct i2c_smbus_alert_setup alert_data;
126 	struct i2c_client *ara;
127 };
128 
129 static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
130 {
131 	__raw_writeq(val, addr);
132 	__raw_readq(addr);	/* wait for write to land */
133 }
134 
135 /**
136  * octeon_i2c_reg_write - write an I2C core register
137  * @i2c: The struct octeon_i2c
138  * @eop_reg: Register selector
139  * @data: Value to be written
140  *
141  * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
142  */
143 static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
144 {
145 	u64 tmp;
146 
147 	__raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + SW_TWSI(i2c));
148 
149 	readq_poll_timeout(i2c->twsi_base + SW_TWSI(i2c), tmp, tmp & SW_TWSI_V,
150 			   I2C_OCTEON_EVENT_WAIT, i2c->adap.timeout);
151 }
152 
153 #define octeon_i2c_ctl_write(i2c, val)					\
154 	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, val)
155 #define octeon_i2c_data_write(i2c, val)					\
156 	octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, val)
157 
158 /**
159  * octeon_i2c_reg_read - read lower bits of an I2C core register
160  * @i2c: The struct octeon_i2c
161  * @eop_reg: Register selector
162  *
163  * Returns the data.
164  *
165  * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
166  */
167 static inline int octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg,
168 				      int *error)
169 {
170 	u64 tmp;
171 	int ret;
172 
173 	__raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + SW_TWSI(i2c));
174 
175 	ret = readq_poll_timeout(i2c->twsi_base + SW_TWSI(i2c), tmp,
176 				 tmp & SW_TWSI_V, I2C_OCTEON_EVENT_WAIT,
177 				 i2c->adap.timeout);
178 	if (error)
179 		*error = ret;
180 	return tmp & 0xFF;
181 }
182 
183 #define octeon_i2c_ctl_read(i2c)					\
184 	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL, NULL)
185 #define octeon_i2c_data_read(i2c, error)				\
186 	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA, error)
187 #define octeon_i2c_stat_read(i2c)					\
188 	octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT, NULL)
189 
190 /**
191  * octeon_i2c_read_int - read the TWSI_INT register
192  * @i2c: The struct octeon_i2c
193  *
194  * Returns the value of the register.
195  */
196 static inline u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
197 {
198 	return __raw_readq(i2c->twsi_base + TWSI_INT(i2c));
199 }
200 
201 /**
202  * octeon_i2c_write_int - write the TWSI_INT register
203  * @i2c: The struct octeon_i2c
204  * @data: Value to be written
205  */
206 static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
207 {
208 	octeon_i2c_writeq_flush(data, i2c->twsi_base + TWSI_INT(i2c));
209 }
210 
211 /* Prototypes */
212 irqreturn_t octeon_i2c_isr(int irq, void *dev_id);
213 int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
214 int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c);
215 void octeon_i2c_set_clock(struct octeon_i2c *i2c);
216 extern struct i2c_bus_recovery_info octeon_i2c_recovery_info;
217