X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fdrv%2Fi2c_bitbang.c;h=9456d362aabc5aa52f8c8f53e69ca1aa7689ed63;hb=41718ab2098bd5640da265c34f1ecb79a4123d39;hp=07dd2c04f32ba888305abc0bd14b022cd4e9e87b;hpb=03c14d1d807783de7b8560727843802c00b19d0f;p=bertos.git diff --git a/bertos/drv/i2c_bitbang.c b/bertos/drv/i2c_bitbang.c index 07dd2c04..9456d362 100644 --- a/bertos/drv/i2c_bitbang.c +++ b/bertos/drv/i2c_bitbang.c @@ -32,11 +32,12 @@ * * \brief I2C bitbang driver (implementation) * - * \version $Id: adc.c 1604 2008-08-10 17:19:51Z bernie $ * \author Francesco Sacchi + * \author Daniele Basile */ -#include "i2c.h" +#include "hw/hw_i2c_bitbang.h" + #include "cfg/cfg_i2c.h" #define LOG_LEVEL I2C_LOG_LEVEL @@ -47,9 +48,13 @@ #include #include +#include + #include -#include "hw/hw_i2c_bitbang.h" +#include + +#if !CONFIG_I2C_DISABLE_OLD_API INLINE bool i2c_bitbang_start(void) { @@ -58,7 +63,7 @@ INLINE bool i2c_bitbang_start(void) I2C_HALFBIT_DELAY(); SDA_LO; I2C_HALFBIT_DELAY(); - ASSERT(!SDA_IN); + return !SDA_IN; } @@ -164,17 +169,259 @@ int i2c_bitbang_get(bool ack) return (int)(uint8_t)data; } -MOD_DEFINE(i2c); +#endif /* !CONFIG_I2C_DISABLE_OLD_API */ + +/* + * New I2C API + */ +static bool old_api = false; +#define I2C_DEV(i2c) ((int)((i2c)->hw)) + +static void i2c_bitbang_stop_1(struct I2c *i2c) +{ + if (old_api) + { + SDA_LO; + SCL_HI; + I2C_HALFBIT_DELAY(); + SDA_HI; + } + else + { + i2c_sdaLo(I2C_DEV(i2c)); + i2c_sclHi(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + i2c_sdaHi(I2C_DEV(i2c)); + } +} + +INLINE bool i2c_bitbang_start_1(struct I2c *i2c) +{ + bool ret; + /* Clear all error, we restart */ + i2c->errors &= ~(I2C_NO_ACK | I2C_ARB_LOST); + + if (old_api) + { + SDA_HI; + SCL_HI; + I2C_HALFBIT_DELAY(); + SDA_LO; + I2C_HALFBIT_DELAY(); + + ret = !SDA_IN; + } + else + { + i2c_sdaHi(I2C_DEV(i2c)); + i2c_sclHi(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + i2c_sdaLo(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + + ret = !i2c_sdaIn(I2C_DEV(i2c)); + } + + return ret; +} + + +static uint8_t i2c_bitbang_getc(struct I2c *i2c) +{ + uint8_t data = 0; + if (old_api) + { + for (uint8_t i = 0x80; i != 0; i >>= 1) + { + SCL_LO; + I2C_HALFBIT_DELAY(); + SCL_HI; + if (SDA_IN) + data |= i; + else + data &= ~i; + + I2C_HALFBIT_DELAY(); + } + SCL_LO; + + /* Generate ACK/NACK */ + if (i2c->xfer_size > 1) + SDA_LO; + else + SDA_HI; + + I2C_HALFBIT_DELAY(); + SCL_HI; + I2C_HALFBIT_DELAY(); + SCL_LO; + SDA_HI; + } + else + { + for (uint8_t i = 0x80; i != 0; i >>= 1) + { + i2c_sclLo(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + i2c_sclHi(I2C_DEV(i2c)); + if (i2c_sdaIn(I2C_DEV(i2c))) + data |= i; + else + data &= ~i; + + i2c_halfbitDelay(I2C_DEV(i2c)); + } + i2c_sclLo(I2C_DEV(i2c)); + + /* Generate ACK/NACK */ + if (i2c->xfer_size > 1) + i2c_sdaLo(I2C_DEV(i2c)); + else + i2c_sdaHi(I2C_DEV(i2c)); + + i2c_halfbitDelay(I2C_DEV(i2c)); + i2c_sclHi(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + i2c_sclLo(I2C_DEV(i2c)); + i2c_sdaHi(I2C_DEV(i2c)); + } + + /* Generate stop condition (if requested) */ + if ((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP)) + i2c_bitbang_stop_1(i2c); + + return data; +} + +INLINE void i2c_bitbang_putcStop(struct I2c *i2c, uint8_t _data, bool stop) +{ + /* Add ACK bit */ + uint16_t data = (_data << 1) | 1; + bool ack; + + if (old_api) + { + for (uint16_t i = 0x100; i != 0; i >>= 1) + { + SCL_LO; + if (data & i) + SDA_HI; + else + SDA_LO; + I2C_HALFBIT_DELAY(); + + SCL_HI; + I2C_HALFBIT_DELAY(); + } + + ack = !SDA_IN; + SCL_LO; + I2C_HALFBIT_DELAY(); + } + else + { + for (uint16_t i = 0x100; i != 0; i >>= 1) + { + i2c_sclLo(I2C_DEV(i2c)); + if (data & i) + i2c_sdaHi(I2C_DEV(i2c)); + else + i2c_sdaLo(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + + i2c_sclHi(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + } + ack = !i2c_sdaIn(I2C_DEV(i2c)); + + i2c_sclLo(I2C_DEV(i2c)); + i2c_halfbitDelay(I2C_DEV(i2c)); + } + + if (!ack) + i2c->errors |= I2C_NO_ACK; + + /* Generate stop condition (if requested) */ + if (stop || i2c->errors) + i2c_bitbang_stop_1(i2c); +} + +static void i2c_bitbang_putc(struct I2c *i2c, uint8_t data) +{ + i2c_bitbang_putcStop(i2c, data, + (i2c->xfer_size == 1) && (i2c->flags & I2C_STOP)); +} + +static void i2c_bitbang_start_2(struct I2c *i2c, uint16_t slave_addr) +{ + if (i2c->flags & I2C_START_R) + slave_addr |= I2C_READBIT; + else + slave_addr &= ~I2C_READBIT; + + /* + * Loop on the select write sequence: when the device is busy + * writing previously sent data it will reply to the SLA_W + * control byte with a NACK. In this case, we must + * keep trying until the device responds with an ACK. + */ + ticks_t start = timer_clock(); + while (i2c_bitbang_start_1(i2c)) + { + i2c_bitbang_putcStop(i2c, slave_addr, false); + + if (!(i2c->errors & I2C_NO_ACK)) + return; + else if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT)) + { + LOG_ERR("Timeout on I2C start\n"); + i2c->errors |= I2C_START_TIMEOUT; + i2c_bitbang_stop_1(i2c); + return; + } + } + + LOG_ERR("START arbitration lost\n"); + i2c->errors |= I2C_ARB_LOST; + i2c_bitbang_stop_1(i2c); + return; +} + + +static const I2cVT i2c_bitbang_vt = +{ + .start = i2c_bitbang_start_2, + .getc = i2c_bitbang_getc, + .putc = i2c_bitbang_putc, + .write = i2c_genericWrite, + .read = i2c_genericRead, +}; + /** * Initialize i2c module. */ -void i2c_bitbang_init(void) +void i2c_hw_bitbangInit(I2c *i2c, int dev) { MOD_CHECK(timer); - I2C_BITBANG_HW_INIT; - SDA_HI; - SCL_HI; - MOD_INIT(i2c); + if (dev == I2C_BITBANG_OLD) + old_api = true; + else + i2c->hw = (struct I2cHardware *)(dev - I2C_BITBANG0); + + i2c->vt = &i2c_bitbang_vt; + + if (old_api) + { + I2C_BITBANG_HW_INIT; + SDA_HI; + SCL_HI; + } + else + { + i2c_bitbangInit(I2C_DEV(i2c)); + i2c_sdaHi(I2C_DEV(i2c)); + i2c_sclHi(I2C_DEV(i2c)); + } }