1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <linux/atomic.h>
3 #include <linux/bitfield.h>
4 #include <linux/clk.h>
5 #include <linux/delay.h>
6 #include <linux/device.h>
7 #include <linux/i2c.h>
8 #include <linux/i2c-smbus.h>
9 #include <linux/io.h>
10 #include <linux/kernel.h>
11 #include <linux/pci.h>
12
13 /* Controller command patterns */
14 #define SW_TWSI_V BIT_ULL(63) /* Valid bit */
15 #define SW_TWSI_EIA BIT_ULL(61) /* Extended internal address */
16 #define SW_TWSI_R BIT_ULL(56) /* Result or read bit */
17 #define SW_TWSI_SOVR BIT_ULL(55) /* Size override */
18 #define SW_TWSI_SIZE_SHIFT 52
19 #define SW_TWSI_ADDR_SHIFT 40
20 #define SW_TWSI_IA_SHIFT 32 /* Internal address */
21
22 /* Controller opcode word (bits 60:57) */
23 #define SW_TWSI_OP_SHIFT 57
24 #define SW_TWSI_OP_7 (0ULL << SW_TWSI_OP_SHIFT)
25 #define SW_TWSI_OP_7_IA (1ULL << SW_TWSI_OP_SHIFT)
26 #define SW_TWSI_OP_10 (2ULL << SW_TWSI_OP_SHIFT)
27 #define SW_TWSI_OP_10_IA (3ULL << SW_TWSI_OP_SHIFT)
28 #define SW_TWSI_OP_TWSI_CLK (4ULL << SW_TWSI_OP_SHIFT)
29 #define SW_TWSI_OP_EOP (6ULL << SW_TWSI_OP_SHIFT) /* Extended opcode */
30
31 /* Controller extended opcode word (bits 34:32) */
32 #define SW_TWSI_EOP_SHIFT 32
33 #define SW_TWSI_EOP_TWSI_DATA (SW_TWSI_OP_EOP | 1ULL << SW_TWSI_EOP_SHIFT)
34 #define SW_TWSI_EOP_TWSI_CTL (SW_TWSI_OP_EOP | 2ULL << SW_TWSI_EOP_SHIFT)
35 #define SW_TWSI_EOP_TWSI_CLKCTL (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
36 #define SW_TWSI_EOP_TWSI_STAT (SW_TWSI_OP_EOP | 3ULL << SW_TWSI_EOP_SHIFT)
37 #define SW_TWSI_EOP_TWSI_RST (SW_TWSI_OP_EOP | 7ULL << SW_TWSI_EOP_SHIFT)
38
39 /* Controller command and status bits */
40 #define TWSI_CTL_CE 0x80 /* High level controller enable */
41 #define TWSI_CTL_ENAB 0x40 /* Bus enable */
42 #define TWSI_CTL_STA 0x20 /* Controller-mode start, HW clears when done */
43 #define TWSI_CTL_STP 0x10 /* Controller-mode stop, HW clears when done */
44 #define TWSI_CTL_IFLG 0x08 /* HW event, SW writes 0 to ACK */
45 #define TWSI_CTL_AAK 0x04 /* Assert ACK */
46
47 /* Status values */
48 #define STAT_BUS_ERROR 0x00
49 #define STAT_START 0x08
50 #define STAT_REP_START 0x10
51 #define STAT_TXADDR_ACK 0x18
52 #define STAT_TXADDR_NAK 0x20
53 #define STAT_TXDATA_ACK 0x28
54 #define STAT_TXDATA_NAK 0x30
55 #define STAT_LOST_ARB_38 0x38
56 #define STAT_RXADDR_ACK 0x40
57 #define STAT_RXADDR_NAK 0x48
58 #define STAT_RXDATA_ACK 0x50
59 #define STAT_RXDATA_NAK 0x58
60 #define STAT_SLAVE_60 0x60
61 #define STAT_LOST_ARB_68 0x68
62 #define STAT_SLAVE_70 0x70
63 #define STAT_LOST_ARB_78 0x78
64 #define STAT_SLAVE_80 0x80
65 #define STAT_SLAVE_88 0x88
66 #define STAT_GENDATA_ACK 0x90
67 #define STAT_GENDATA_NAK 0x98
68 #define STAT_SLAVE_A0 0xA0
69 #define STAT_SLAVE_A8 0xA8
70 #define STAT_LOST_ARB_B0 0xB0
71 #define STAT_SLAVE_LOST 0xB8
72 #define STAT_SLAVE_NAK 0xC0
73 #define STAT_SLAVE_ACK 0xC8
74 #define STAT_AD2W_ACK 0xD0
75 #define STAT_AD2W_NAK 0xD8
76 #define STAT_WDOG_TOUT 0xF0
77 #define STAT_IDLE 0xF8
78
79 /* TWSI_INT values */
80 #define TWSI_INT_ST_INT BIT_ULL(0)
81 #define TWSI_INT_TS_INT BIT_ULL(1)
82 #define TWSI_INT_CORE_INT BIT_ULL(2)
83 #define TWSI_INT_ST_EN BIT_ULL(4)
84 #define TWSI_INT_TS_EN BIT_ULL(5)
85 #define TWSI_INT_CORE_EN BIT_ULL(6)
86 #define TWSI_INT_SDA_OVR BIT_ULL(8)
87 #define TWSI_INT_SCL_OVR BIT_ULL(9)
88 #define TWSI_INT_SDA BIT_ULL(10)
89 #define TWSI_INT_SCL BIT_ULL(11)
90
91 #define I2C_OCTEON_EVENT_WAIT 80 /* microseconds */
92
93 /* Register offsets */
94 struct octeon_i2c_reg_offset {
95 unsigned int sw_twsi;
96 unsigned int twsi_int;
97 unsigned int sw_twsi_ext;
98 unsigned int mode;
99 };
100
101 #define OCTEON_REG_SW_TWSI(x) ((x)->roff.sw_twsi)
102 #define OCTEON_REG_TWSI_INT(x) ((x)->roff.twsi_int)
103 #define OCTEON_REG_SW_TWSI_EXT(x) ((x)->roff.sw_twsi_ext)
104 #define OCTEON_REG_MODE(x) ((x)->roff.mode)
105
106 /* Set REFCLK_SRC and HS_MODE in TWSX_MODE register */
107 #define TWSX_MODE_REFCLK_SRC BIT(4)
108 #define TWSX_MODE_HS_MODE BIT(0)
109 #define TWSX_MODE_HS_MASK (TWSX_MODE_REFCLK_SRC | TWSX_MODE_HS_MODE)
110
111 /* Set BUS_MON_RST to reset bus monitor */
112 #define BUS_MON_RST_MASK BIT(3)
113
114 struct octeon_i2c {
115 wait_queue_head_t queue;
116 struct i2c_adapter adap;
117 struct octeon_i2c_reg_offset roff;
118 struct clk *clk;
119 int irq;
120 int hlc_irq; /* For cn7890 only */
121 u32 twsi_freq;
122 int sys_freq;
123 void __iomem *twsi_base;
124 struct device *dev;
125 bool hlc_enabled;
126 bool broken_irq_mode;
127 bool broken_irq_check;
128 void (*int_enable)(struct octeon_i2c *);
129 void (*int_disable)(struct octeon_i2c *);
130 void (*hlc_int_enable)(struct octeon_i2c *);
131 void (*hlc_int_disable)(struct octeon_i2c *);
132 atomic_t int_enable_cnt;
133 atomic_t hlc_int_enable_cnt;
134 struct i2c_smbus_alert_setup alert_data;
135 struct i2c_client *ara;
136 };
137
octeon_i2c_writeq_flush(u64 val,void __iomem * addr)138 static inline void octeon_i2c_writeq_flush(u64 val, void __iomem *addr)
139 {
140 __raw_writeq(val, addr);
141 __raw_readq(addr); /* wait for write to land */
142 }
143
144 /**
145 * octeon_i2c_reg_write - write an I2C core register
146 * @i2c: The struct octeon_i2c
147 * @eop_reg: Register selector
148 * @data: Value to be written
149 *
150 * The I2C core registers are accessed indirectly via the OCTEON_REG_SW_TWSI CSR.
151 */
octeon_i2c_reg_write(struct octeon_i2c * i2c,u64 eop_reg,u8 data)152 static inline void octeon_i2c_reg_write(struct octeon_i2c *i2c, u64 eop_reg, u8 data)
153 {
154 int tries = 1000;
155 u64 tmp;
156
157 __raw_writeq(SW_TWSI_V | eop_reg | data, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
158 do {
159 tmp = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
160 if (--tries < 0)
161 return;
162 } while ((tmp & SW_TWSI_V) != 0);
163 }
164
165 #define octeon_i2c_ctl_write(i2c, val) \
166 octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_CTL, val)
167 #define octeon_i2c_data_write(i2c, val) \
168 octeon_i2c_reg_write(i2c, SW_TWSI_EOP_TWSI_DATA, val)
169
170 /**
171 * octeon_i2c_reg_read - read lower bits of an I2C core register
172 * @i2c: The struct octeon_i2c
173 * @eop_reg: Register selector
174 *
175 * Returns the data.
176 *
177 * The I2C core registers are accessed indirectly via the SW_TWSI CSR.
178 */
octeon_i2c_reg_read(struct octeon_i2c * i2c,u64 eop_reg,int * error)179 static inline int octeon_i2c_reg_read(struct octeon_i2c *i2c, u64 eop_reg,
180 int *error)
181 {
182 int tries = 1000;
183 u64 tmp;
184
185 __raw_writeq(SW_TWSI_V | eop_reg | SW_TWSI_R, i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
186 do {
187 tmp = __raw_readq(i2c->twsi_base + OCTEON_REG_SW_TWSI(i2c));
188 if (--tries < 0) {
189 /* signal that the returned data is invalid */
190 if (error)
191 *error = -EIO;
192 return 0;
193 }
194 } while ((tmp & SW_TWSI_V) != 0);
195
196 return tmp & 0xFF;
197 }
198
199 #define octeon_i2c_ctl_read(i2c) \
200 octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_CTL, NULL)
201 #define octeon_i2c_data_read(i2c, error) \
202 octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_DATA, error)
203 #define octeon_i2c_stat_read(i2c) \
204 octeon_i2c_reg_read(i2c, SW_TWSI_EOP_TWSI_STAT, NULL)
205
206 /**
207 * octeon_i2c_read_int - read the OCTEON_REG_TWSI_INT register
208 * @i2c: The struct octeon_i2c
209 *
210 * Returns the value of the register.
211 */
octeon_i2c_read_int(struct octeon_i2c * i2c)212 static inline u64 octeon_i2c_read_int(struct octeon_i2c *i2c)
213 {
214 return __raw_readq(i2c->twsi_base + OCTEON_REG_TWSI_INT(i2c));
215 }
216
217 /**
218 * octeon_i2c_write_int - write the OCTEON_REG_TWSI_INT register
219 * @i2c: The struct octeon_i2c
220 * @data: Value to be written
221 */
octeon_i2c_write_int(struct octeon_i2c * i2c,u64 data)222 static inline void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
223 {
224 octeon_i2c_writeq_flush(data, i2c->twsi_base + OCTEON_REG_TWSI_INT(i2c));
225 }
226
227 #define IS_LS_FREQ(twsi_freq) ((twsi_freq) <= 400000)
228 #define PCI_SUBSYS_DEVID_9XXX 0xB
229 #define PCI_SUBSYS_MASK GENMASK(15, 12)
230 /**
231 * octeon_i2c_is_otx2 - check for chip ID
232 * @pdev: PCI dev structure
233 *
234 * Returns true if the device is an OcteonTX2, false otherwise.
235 */
octeon_i2c_is_otx2(struct pci_dev * pdev)236 static inline bool octeon_i2c_is_otx2(struct pci_dev *pdev)
237 {
238 u32 chip_id = FIELD_GET(PCI_SUBSYS_MASK, pdev->subsystem_device);
239
240 return (chip_id == PCI_SUBSYS_DEVID_9XXX);
241 }
242
243 /* Prototypes */
244 irqreturn_t octeon_i2c_isr(int irq, void *dev_id);
245 int octeon_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
246 int octeon_i2c_init_lowlevel(struct octeon_i2c *i2c);
247 void octeon_i2c_set_clock(struct octeon_i2c *i2c);
248 extern struct i2c_bus_recovery_info octeon_i2c_recovery_info;
249