X-Git-Url: https://codewiz.org/gitweb?a=blobdiff_plain;f=bertos%2Fdrv%2Fi2c_bitbang.c;h=8bc2ffad0104abcae5e7770d603c45a5809e3439;hb=39184f9b190fdcfec2f17aad6f0de8b2edf04a02;hp=7067d91917a967e2178ee4348857499374dea966;hpb=2ec062d0fa64791fc844d8385a8cf06e8df5dab6;p=bertos.git diff --git a/bertos/drv/i2c_bitbang.c b/bertos/drv/i2c_bitbang.c index 7067d919..8bc2ffad 100644 --- a/bertos/drv/i2c_bitbang.c +++ b/bertos/drv/i2c_bitbang.c @@ -32,56 +32,74 @@ * * \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 "timer.h" #include "hw/hw_i2c_bitbang.h" -#define I2C_PERIOD DIV_ROUND(500000UL / CONFIG_I2C_FREQ) +#include "cfg/cfg_i2c.h" -INLINE bool i2c_start(void) +#define LOG_LEVEL I2C_LOG_LEVEL +#define LOG_FORMAT I2C_LOG_FORMAT + +#include +#include +#include + +#include +#include + +#include + +#include + +#if !CONFIG_I2C_DISABLE_OLD_API + +INLINE bool i2c_bitbang_start(void) { SDA_HI; SCL_HI; - timer_udelay(I2C_PERIOD); - SDA_LOW; - timer_udelay(I2C_PERIOD); - return !SDA; + I2C_HALFBIT_DELAY(); + SDA_LO; + I2C_HALFBIT_DELAY(); + + return !SDA_IN; } -void i2c_stop(void) +void i2c_bitbang_stop(void) { + SDA_LO; SCL_HI; - timer_udelay(I2C_PERIOD); + I2C_HALFBIT_DELAY(); SDA_HI; } -bool i2c_put(uint8_t _data) +bool i2c_bitbang_put(uint8_t _data) { + /* Add ACK bit */ uint16_t data = (_data << 1) | 1; - for (uint16_t i = 0x100; i >= 0; i >>= 1) + + for (uint16_t i = 0x100; i != 0; i >>= 1) { SCL_LO; - timer_udelay(I2C_PERIOD); if (data & i) SDA_HI; else SDA_LO; + I2C_HALFBIT_DELAY(); + SCL_HI; - timer_udelay(I2C_PERIOD); - ASSERT(SDA == (data & i)); + I2C_HALFBIT_DELAY(); } - bool ack = !SDA; - ASSERT(ack); + + bool ack = !SDA_IN; SCL_LO; - timer_udelay(I2C_PERIOD); + I2C_HALFBIT_DELAY(); return ack; } -bool i2c_start_w(uint8_t id) +bool i2c_bitbang_start_w(uint8_t id) { id &= ~I2C_READBIT; /* @@ -91,26 +109,27 @@ bool i2c_start_w(uint8_t id) * keep trying until the deveice responds with an ACK. */ ticks_t start = timer_clock(); - while (i2c_start()) + while (i2c_bitbang_start()) { - if (i2c_put(id)) + if (i2c_bitbang_put(id)) return true; - else if (timer_clock() - start > ms_to_ticks(CONFIG_TWI_START_TIMEOUT)) + else if (timer_clock() - start > ms_to_ticks(CONFIG_I2C_START_TIMEOUT)) { LOG_ERR("Timeout on I2C start write\n"); break; } + //LOG_INFO("Rep start\n"); } return false; } -bool i2c_start_r(uint8_t id) +bool i2c_bitbang_start_r(uint8_t id) { id |= I2C_READBIT; - if (i2c_start()) + if (i2c_bitbang_start()) { - if (i2c_put(id)) + if (i2c_bitbang_put(id)) return true; LOG_ERR("NACK on I2c start read\n"); @@ -119,28 +138,204 @@ bool i2c_start_r(uint8_t id) return false; } -int i2c_get(bool ack) +int i2c_bitbang_get(bool ack) { uint8_t data = 0; - for (uint8_t i = 0x80; i >= 0; i >>= 1) + for (uint8_t i = 0x80; i != 0; i >>= 1) { SCL_LO; - timer_udelay(I2C_PERIOD); + I2C_HALFBIT_DELAY(); SCL_HI; - timer_udelay(I2C_PERIOD); - if (SDA) + if (SDA_IN) data |= i; + else + data &= ~i; + + I2C_HALFBIT_DELAY(); } SCL_LO; - timer_udelay(I2C_PERIOD); if (ack) SDA_LO; else SDA_HI; + I2C_HALFBIT_DELAY(); SCL_HI; + I2C_HALFBIT_DELAY(); + SCL_LO; + SDA_HI; /* avoid sign extension */ return (int)(uint8_t)data; } +MOD_DEFINE(i2c); + +/** + * Initialize i2c module. + */ +void i2c_bitbang_init(void) +{ + MOD_CHECK(timer); + I2C_BITBANG_HW_INIT; + SDA_HI; + SCL_HI; + MOD_INIT(i2c); +} +#endif /* !CONFIG_I2C_DISABLE_OLD_API */ + +/* + * New I2C API + */ +#define I2C_DEV(i2c) ((int)((i2c)->hw)) + +static void i2c_bitbang_stop_1(struct I2c *i2c) +{ + i2c_hw_sdaLo(I2C_DEV(i2c)); + i2c_hw_sclHi(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + i2c_hw_sdaHi(I2C_DEV(i2c)); +} + +INLINE bool i2c_bitbang_start_1(struct I2c *i2c) +{ + 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)); + + return !i2c_hw_sdaIn(I2C_DEV(i2c)); +} + + +static uint8_t i2c_bitbang_getc(struct I2c *i2c) +{ + uint8_t data = 0; + for (uint8_t i = 0x80; i != 0; i >>= 1) + { + 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_hw_halfbitDelay(I2C_DEV(i2c)); + } + i2c_hw_sclLo(I2C_DEV(i2c)); + + /* Generate ACK/NACK */ + if (i2c->xfer_size > 1) + i2c_hw_sdaLo(I2C_DEV(i2c)); + else + i2c_hw_sdaHi(I2C_DEV(i2c)); + + 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_1(i2c); + + return 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) + { + i2c_hw_sclLo(I2C_DEV(i2c)); + if (data & i) + i2c_hw_sdaHi(I2C_DEV(i2c)); + else + i2c_hw_sdaLo(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + + i2c_hw_sclHi(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + } + + bool ack = !i2c_hw_sdaIn(I2C_DEV(i2c)); + i2c_hw_sclLo(I2C_DEV(i2c)); + i2c_hw_halfbitDelay(I2C_DEV(i2c)); + + if (!ack) + { + LOG_ERR("NO ACK received\n"); + i2c->errors |= I2C_NO_ACK; + } + + /* Generate stop condition (if requested) */ + if (((i2c->xfer_size == 1) && (i2c->flags & I2C_STOP)) || i2c->errors) + 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)); +} +