X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fdrv%2Fi2c_bitbang.c;h=2cf0e573aaee4b918cb3c45f727e895e8e3090d3;hb=eea6e7e95a7c2ac1343ea0485782efa02a737ec2;hp=45847c93c4e598bc2f0d66106bd110294cdaa2ed;hpb=ec1f9b136d8b9ec44272ba7ab8ddc4b729589af2;p=bertos.git diff --git a/bertos/drv/i2c_bitbang.c b/bertos/drv/i2c_bitbang.c index 45847c93..2cf0e573 100644 --- a/bertos/drv/i2c_bitbang.c +++ b/bertos/drv/i2c_bitbang.c @@ -33,9 +33,11 @@ * \brief I2C bitbang driver (implementation) * * \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 @@ -46,9 +48,12 @@ #include #include +#include + #include -#include "hw/hw_i2c_bitbang.h" +#include + INLINE bool i2c_bitbang_start(void) { @@ -181,106 +186,85 @@ void i2c_bitbang_init(void) /* * New I2C API */ +#define I2C_DEV(i2c) ((int)((i2c)->hw)) -static void i2c_bitbang_stop(struct I2c *i2c) +static void i2c_bitbang_stop_1(struct I2c *i2c) { - SDA_LO; - SCL_HI; - I2C_HALFBIT_DELAY(); - SDA_HI; + i2c_hw_sdaLo(I2C_DEV(i2c)); + i2c_hw_sclHi(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + i2c_hw_sdaHi(I2C_DEV(i2c)); } - -void i2c_bitbang_start(struct I2c *i2c, uint16_t slave_addr) +INLINE bool i2c_bitbang_start_1(struct I2c *i2c) { - if (i2c->flags & I2C_START_R) - slave_addr |= I2C_READBIT; - else - slave_addr &= ~I2C_READBIT; + i2c_hw_sdaHi(I2C_DEV(i2c)); + i2c_hw_sclHi(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + i2c_hw_sdaLo(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); - /* - * 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 deveice responds with an ACK. - */ - ticks_t start = timer_clock(); - while (i2c_bitbang_start()) - { - if (i2c_bitbang_put(slave_addr)) - 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(i2c); - return; - } - } - - LOG_ERR("START arbitration lost\n"); - i2c->errors |= I2C_ARB_LOST; - i2c_bitbang_stop(i2c); - return; + return !i2c_hw_sdaIn(I2C_DEV(i2c)); } -uint8_t i2c_bitbang_get(struct I2c *i2c) + +static uint8_t i2c_bitbang_getc(struct I2c *i2c) { uint8_t data = 0; for (uint8_t i = 0x80; i != 0; i >>= 1) { - SCL_LO; - I2C_HALFBIT_DELAY(); - SCL_HI; - if (SDA_IN) + i2c_hw_sclLo(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + i2c_hw_sclHi(I2C_DEV(i2c)); + if (i2c_hw_sdaIn(I2C_DEV(i2c))) data |= i; else data &= ~i; - I2C_HALFBIT_DELAY(); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); } - SCL_LO; + i2c_hw_sclLo(I2C_DEV(i2c)); /* Generate ACK/NACK */ if (i2c->xfer_size > 1) - SDA_LO; + i2c_hw_sdaLo(I2C_DEV(i2c)); else - SDA_HI; + i2c_hw_sdaHi(I2C_DEV(i2c)); - I2C_HALFBIT_DELAY(); - SCL_HI; - I2C_HALFBIT_DELAY(); - SCL_LO; - SDA_HI; + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + i2c_hw_sclHi(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + i2c_hw_sclLo(I2C_DEV(i2c)); + i2c_hw_sdaHi(I2C_DEV(i2c)); /* Generate stop condition (if requested) */ if ((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP)) - i2c_bitbang_stop(i2c); + i2c_bitbang_stop_1(i2c); return data; } -void i2c_bitbang_put(struct I2c *i2c, uint8_t _data) +static void i2c_bitbang_putc(struct I2c *i2c, uint8_t _data) { /* Add ACK bit */ uint16_t data = (_data << 1) | 1; for (uint16_t i = 0x100; i != 0; i >>= 1) { - SCL_LO; + i2c_hw_sclLo(I2C_DEV(i2c)); if (data & i) - SDA_HI; + i2c_hw_sdaHi(I2C_DEV(i2c)); else - SDA_LO; - I2C_HALFBIT_DELAY(); + i2c_hw_sdaLo(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); - SCL_HI; - I2C_HALFBIT_DELAY(); + i2c_hw_sclHi(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); } - bool ack = !SDA_IN; - SCL_LO; - I2C_HALFBIT_DELAY(); + bool ack = !i2c_hw_sdaIn(I2C_DEV(i2c)); + i2c_hw_sclLo(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); if (!ack) { @@ -290,5 +274,67 @@ void i2c_bitbang_put(struct I2c *i2c, uint8_t _data) /* Generate stop condition (if requested) */ if (((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP)) || i2c->errors) - i2c_bitbang_stop(i2c); + i2c_bitbang_stop_1(i2c); +} + + +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 deveice responds with an ACK. + */ + ticks_t start = timer_clock(); + while (i2c_bitbang_start_1(i2c)) + { + i2c_bitbang_putc(i2c, slave_addr); + + 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_hw_bitbangInit(I2c *i2c, int dev) +{ + MOD_CHECK(timer); + i2c->hw = (struct I2cHardware *)(dev - I2C_BITBANG0); + i2c->vt = &i2c_bitbang_vt; + + i2c_hw_bitbang_init(I2C_DEV(i2c)); + i2c_hw_sdaHi(I2C_DEV(i2c)); + i2c_hw_sclHi(I2C_DEV(i2c)); +} +