drivers/i2c/busses/i2c-octeon-core.h

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