diff options
Diffstat (limited to 'nvkm/subdev/i2c/bit.c')
| -rw-r--r-- | nvkm/subdev/i2c/bit.c | 234 |
1 files changed, 0 insertions, 234 deletions
diff --git a/nvkm/subdev/i2c/bit.c b/nvkm/subdev/i2c/bit.c deleted file mode 100644 index 813ffc96e..000000000 --- a/nvkm/subdev/i2c/bit.c +++ /dev/null @@ -1,234 +0,0 @@ -/* - * Copyright 2012 Red Hat Inc. - * - * Permission is hereby granted, free of charge, to any person obtaining a - * copy of this software and associated documentation files (the "Software"), - * to deal in the Software without restriction, including without limitation - * the rights to use, copy, modify, merge, publish, distribute, sublicense, - * and/or sell copies of the Software, and to permit persons to whom the - * Software is furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR - * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, - * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR - * OTHER DEALINGS IN THE SOFTWARE. - * - * Authors: Ben Skeggs - */ - -#include "priv.h" - -#ifdef CONFIG_NOUVEAU_I2C_INTERNAL -#define T_TIMEOUT 2200000 -#define T_RISEFALL 1000 -#define T_HOLD 5000 - -static inline void -i2c_drive_scl(struct nouveau_i2c_port *port, int state) -{ - port->func->drive_scl(port, state); -} - -static inline void -i2c_drive_sda(struct nouveau_i2c_port *port, int state) -{ - port->func->drive_sda(port, state); -} - -static inline int -i2c_sense_scl(struct nouveau_i2c_port *port) -{ - return port->func->sense_scl(port); -} - -static inline int -i2c_sense_sda(struct nouveau_i2c_port *port) -{ - return port->func->sense_sda(port); -} - -static void -i2c_delay(struct nouveau_i2c_port *port, u32 nsec) -{ - udelay((nsec + 500) / 1000); -} - -static bool -i2c_raise_scl(struct nouveau_i2c_port *port) -{ - u32 timeout = T_TIMEOUT / T_RISEFALL; - - i2c_drive_scl(port, 1); - do { - i2c_delay(port, T_RISEFALL); - } while (!i2c_sense_scl(port) && --timeout); - - return timeout != 0; -} - -static int -i2c_start(struct nouveau_i2c_port *port) -{ - int ret = 0; - - if (!i2c_sense_scl(port) || - !i2c_sense_sda(port)) { - i2c_drive_scl(port, 0); - i2c_drive_sda(port, 1); - if (!i2c_raise_scl(port)) - ret = -EBUSY; - } - - i2c_drive_sda(port, 0); - i2c_delay(port, T_HOLD); - i2c_drive_scl(port, 0); - i2c_delay(port, T_HOLD); - return ret; -} - -static void -i2c_stop(struct nouveau_i2c_port *port) -{ - i2c_drive_scl(port, 0); - i2c_drive_sda(port, 0); - i2c_delay(port, T_RISEFALL); - - i2c_drive_scl(port, 1); - i2c_delay(port, T_HOLD); - i2c_drive_sda(port, 1); - i2c_delay(port, T_HOLD); -} - -static int -i2c_bitw(struct nouveau_i2c_port *port, int sda) -{ - i2c_drive_sda(port, sda); - i2c_delay(port, T_RISEFALL); - - if (!i2c_raise_scl(port)) - return -ETIMEDOUT; - i2c_delay(port, T_HOLD); - - i2c_drive_scl(port, 0); - i2c_delay(port, T_HOLD); - return 0; -} - -static int -i2c_bitr(struct nouveau_i2c_port *port) -{ - int sda; - - i2c_drive_sda(port, 1); - i2c_delay(port, T_RISEFALL); - - if (!i2c_raise_scl(port)) - return -ETIMEDOUT; - i2c_delay(port, T_HOLD); - - sda = i2c_sense_sda(port); - - i2c_drive_scl(port, 0); - i2c_delay(port, T_HOLD); - return sda; -} - -static int -i2c_get_byte(struct nouveau_i2c_port *port, u8 *byte, bool last) -{ - int i, bit; - - *byte = 0; - for (i = 7; i >= 0; i--) { - bit = i2c_bitr(port); - if (bit < 0) - return bit; - *byte |= bit << i; - } - - return i2c_bitw(port, last ? 1 : 0); -} - -static int -i2c_put_byte(struct nouveau_i2c_port *port, u8 byte) -{ - int i, ret; - for (i = 7; i >= 0; i--) { - ret = i2c_bitw(port, !!(byte & (1 << i))); - if (ret < 0) - return ret; - } - - ret = i2c_bitr(port); - if (ret == 1) /* nack */ - ret = -EIO; - return ret; -} - -static int -i2c_addr(struct nouveau_i2c_port *port, struct i2c_msg *msg) -{ - u32 addr = msg->addr << 1; - if (msg->flags & I2C_M_RD) - addr |= 1; - return i2c_put_byte(port, addr); -} - -static int -i2c_bit_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) -{ - struct nouveau_i2c_port *port = adap->algo_data; - struct i2c_msg *msg = msgs; - int ret = 0, mcnt = num; - - ret = nouveau_i2c(port)->acquire(port, nsecs_to_jiffies(T_TIMEOUT)); - if (ret) - return ret; - - while (!ret && mcnt--) { - u8 remaining = msg->len; - u8 *ptr = msg->buf; - - ret = i2c_start(port); - if (ret == 0) - ret = i2c_addr(port, msg); - - if (msg->flags & I2C_M_RD) { - while (!ret && remaining--) - ret = i2c_get_byte(port, ptr++, !remaining); - } else { - while (!ret && remaining--) - ret = i2c_put_byte(port, *ptr++); - } - - msg++; - } - - i2c_stop(port); - nouveau_i2c(port)->release(port); - return (ret < 0) ? ret : num; -} -#else -static int -i2c_bit_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) -{ - return -ENODEV; -} -#endif - -static u32 -i2c_bit_func(struct i2c_adapter *adap) -{ - return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; -} - -const struct i2c_algorithm nouveau_i2c_bit_algo = { - .master_xfer = i2c_bit_xfer, - .functionality = i2c_bit_func -}; |