*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
struct stm_i2c *stm_i2c;
};
+#define I2C_FAST 1
+
+#define I2C_TIMEOUT 100
+
#define I2C_IDLE 0
#define I2C_RUNNING 1
#define I2C_ERROR 2
static uint16_t ao_i2c_addr[STM_NUM_I2C];
uint8_t ao_i2c_mutex[STM_NUM_I2C];
+# define I2C_HIGH_SLOW 5000 /* ns, 100kHz clock */
+#ifdef TELEMEGA
+# define I2C_HIGH_FAST 2000 /* ns, 167kHz clock */
+#else
+# define I2C_HIGH_FAST 1000 /* ns, 333kHz clock */
+#endif
+
+# define I2C_RISE_SLOW 500 /* ns */
+# define I2C_RISE_FAST 100 /* ns */
+
+/* Clock period in ns */
+#define CYCLES(period) (((period) * (AO_PCLK1 / 1000)) / 1000000)
+
+#define max(a,b) ((a) > (b) ? (a) : (b))
+#define I2C_CCR_HIGH_SLOW max(4,CYCLES(I2C_HIGH_SLOW))
+#define I2C_CCR_HIGH_FAST max(4,CYCLES(I2C_HIGH_FAST))
+#define I2C_TRISE_SLOW (CYCLES(I2C_RISE_SLOW) + 1)
+#define I2C_TRISE_FAST (CYCLES(I2C_RISE_FAST) + 1)
+
+#if I2C_FAST
+#define I2C_TRISE I2C_TRISE_FAST
+#define I2C_CCR_HIGH I2C_CCR_HIGH_FAST
+#else
+#define I2C_TRISE I2C_TRISE_SLOW
+#define I2C_CCR_HIGH I2C_CCR_HIGH_SLOW
+#endif
+
+#if AO_PCLK1 == 2000000
+# define AO_STM_I2C_CR2_FREQ STM_I2C_CR2_FREQ_2_MHZ
+#endif
+#if AO_PCLK1 == 4000000
+# define AO_STM_I2C_CR2_FREQ STM_I2C_CR2_FREQ_4_MHZ
+#endif
+#if AO_PCLK1 == 8000000
+# define AO_STM_I2C_CR2_FREQ STM_I2C_CR2_FREQ_8_MHZ
+#endif
+#if AO_PCLK1 == 16000000
+# define AO_STM_I2C_CR2_FREQ STM_I2C_CR2_FREQ_16_MHZ
+#endif
+#if AO_PCLK1 == 24000000
+# define AO_STM_I2C_CR2_FREQ STM_I2C_CR2_FREQ_24_MHZ
+#endif
+#if AO_PCLK1 == 32000000
+# define AO_STM_I2C_CR2_FREQ STM_I2C_CR2_FREQ_32_MHZ
+#endif
+
#define AO_STM_I2C_CR1 ((0 << STM_I2C_CR1_SWRST) | \
(0 << STM_I2C_CR1_ALERT) | \
(0 << STM_I2C_CR1_PEC) | \
(1 << STM_I2C_CR1_PE))
#define AO_STM_I2C_CR2 ((0 << STM_I2C_CR2_LAST) | \
- (1 << STM_I2C_CR2_DMAEN) | \
+ (0 << STM_I2C_CR2_DMAEN) | \
(0 << STM_I2C_CR2_ITBUFEN) | \
(0 << STM_I2C_CR2_ITEVTEN) | \
(0 << STM_I2C_CR2_ITERREN) | \
- (STM_I2C_CR2_FREQ_16_MHZ << STM_I2C_CR2_FREQ))
+ (AO_STM_I2C_CR2_FREQ << STM_I2C_CR2_FREQ))
static const struct ao_i2c_stm_info ao_i2c_stm_info[STM_NUM_I2C] = {
{
},
};
+static uint8_t *ao_i2c_recv_data[STM_NUM_I2C];
+static uint16_t ao_i2c_recv_len[STM_NUM_I2C];
+static uint16_t ev_count;
+
static void
ao_i2c_ev_isr(uint8_t index)
{
struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
uint32_t sr1;
+ ++ev_count;
sr1 = stm_i2c->sr1;
if (sr1 & (1 << STM_I2C_SR1_SB))
stm_i2c->dr = ao_i2c_addr[index];
if (sr1 & (1 << STM_I2C_SR1_ADDR)) {
- (void) stm_i2c->sr2;
+ stm_i2c->cr2 &= ~(1UL << STM_I2C_CR2_ITEVTEN);
ao_i2c_state[index] = I2C_RUNNING;
ao_wakeup(&ao_i2c_state[index]);
}
+ if (sr1 & (1 << STM_I2C_SR1_BTF)) {
+ stm_i2c->cr2 &= ~(1UL << STM_I2C_CR2_ITEVTEN);
+ ao_wakeup(&ao_i2c_state[index]);
+ }
+ if (sr1 & (1 << STM_I2C_SR1_RXNE)) {
+ if (ao_i2c_recv_len[index]) {
+ *(ao_i2c_recv_data[index]++) = (uint8_t) stm_i2c->dr;
+ if (!--ao_i2c_recv_len[index])
+ ao_wakeup(&ao_i2c_recv_len[index]);
+ }
+ }
}
void stm_i2c1_ev_isr(void) { ao_i2c_ev_isr(0); }
sr1 = stm_i2c->sr1;
if (sr1 & (1 << STM_I2C_SR1_AF)) {
ao_i2c_state[index] = I2C_ERROR;
- stm_i2c->sr1 = sr1 & ~(1 << STM_I2C_SR1_AF);
+ stm_i2c->sr1 = sr1 & ~(1UL << STM_I2C_SR1_AF);
ao_wakeup(&ao_i2c_state[index]);
}
}
ao_i2c_start(uint8_t index, uint16_t addr)
{
struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
-
+ int t;
+
ao_i2c_state[index] = I2C_IDLE;
ao_i2c_addr[index] = addr;
- stm_i2c->cr2 = AO_STM_I2C_CR2 | (1 << STM_I2C_CR2_ITEVTEN) | (1 << STM_I2C_CR2_ITERREN);
+ stm_i2c->cr2 = AO_STM_I2C_CR2;
stm_i2c->cr1 = AO_STM_I2C_CR1 | (1 << STM_I2C_CR1_START);
- ao_arch_critical(
- while (ao_i2c_state[index] == I2C_IDLE)
- ao_sleep(&ao_i2c_state[index]);
- );
+ for (t = 0; t < I2C_TIMEOUT; t++) {
+ if (!(stm_i2c->cr1 & (1 << STM_I2C_CR1_START)))
+ break;
+ }
+ ao_arch_block_interrupts();
+ stm_i2c->cr2 = AO_STM_I2C_CR2 | (1 << STM_I2C_CR2_ITEVTEN) | (1 << STM_I2C_CR2_ITERREN);
+ ao_i2c_ev_isr(index);
+ while (ao_i2c_state[index] == I2C_IDLE)
+ if (ao_sleep_for(&ao_i2c_state[index], AO_MS_TO_TICKS(250)))
+ break;
+ ao_arch_release_interrupts();
return ao_i2c_state[index] == I2C_RUNNING;
}
-void
-ao_i2c_send(void *block, uint16_t len, uint8_t index)
+static void
+ao_i2c_wait_stop(uint8_t index)
+{
+ struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
+ int t;
+
+ for (t = 0; t < I2C_TIMEOUT; t++) {
+ if (!(stm_i2c->cr1 & (1 << STM_I2C_CR1_STOP)))
+ break;
+ ao_yield();
+ }
+ ao_i2c_state[index] = I2C_IDLE;
+}
+
+static void
+ao_i2c_wait_addr(uint8_t index)
+{
+ struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
+ int t;
+
+ for (t = 0; t < I2C_TIMEOUT; t++)
+ if (!(stm_i2c->sr1 & (1 << STM_I2C_SR1_ADDR)))
+ break;
+ if (t)
+ printf ("wait_addr %d\n", t);
+}
+
+uint8_t
+ao_i2c_send(void *block, uint16_t len, uint8_t index, uint8_t stop)
{
struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
uint8_t tx_dma_index = ao_i2c_stm_info[index].tx_dma_index;
+ /* Clear any pending ADDR bit */
+ (void) stm_i2c->sr2;
+ ao_i2c_wait_addr(index);
+ stm_i2c->cr2 = AO_STM_I2C_CR2 | (1 << STM_I2C_CR2_DMAEN);
ao_dma_set_transfer(tx_dma_index,
&stm_i2c->dr,
block,
(0 << STM_DMA_CCR_PINC) |
(0 << STM_DMA_CCR_CIRC) |
(STM_DMA_CCR_DIR_MEM_TO_PER << STM_DMA_CCR_DIR));
-
+
ao_dma_start(tx_dma_index);
- ao_arch_critical(
- while (!ao_dma_done[tx_dma_index])
- ao_sleep(&ao_dma_done[tx_dma_index]);
- );
+ ao_arch_block_interrupts();
+ while (!ao_dma_done[tx_dma_index])
+ if (ao_sleep_for(&ao_dma_done[tx_dma_index], 1 + len))
+ break;
ao_dma_done_transfer(tx_dma_index);
+ stm_i2c->cr2 = AO_STM_I2C_CR2 | (1 << STM_I2C_CR2_ITEVTEN) | (1 << STM_I2C_CR2_ITERREN);
+ while ((stm_i2c->sr1 & (1 << STM_I2C_SR1_BTF)) == 0)
+ if (ao_sleep_for(&ao_i2c_state[index], 1 + len))
+ break;
+ stm_i2c->cr2 = AO_STM_I2C_CR2;
+ ao_arch_release_interrupts();
+ if (stop) {
+ stm_i2c->cr1 = AO_STM_I2C_CR1 | (1 << STM_I2C_CR1_STOP);
+ ao_i2c_wait_stop(index);
+ }
+ return true;
}
-void
+static void
+ao_i2c_recv_dma_isr(int index)
+{
+ int i;
+ struct stm_i2c *stm_i2c = NULL;
+
+ for (i = 0; i < STM_NUM_I2C; i++)
+ if (index == ao_i2c_stm_info[i].rx_dma_index) {
+ stm_i2c = ao_i2c_stm_info[i].stm_i2c;
+ break;
+ }
+ if (!stm_i2c)
+ return;
+ stm_i2c->cr2 = AO_STM_I2C_CR2 | (1 << STM_I2C_CR2_LAST);
+ ao_dma_done[index] = 1;
+ ao_wakeup(&ao_dma_done[index]);
+}
+
+uint8_t
+ao_i2c_recv(void *block, uint16_t len, uint8_t index, uint8_t stop)
+{
+ struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
+ uint8_t ret = true;
+
+ if (len == 0)
+ return true;
+ if (len == 1) {
+ ao_i2c_recv_data[index] = block;
+ ao_i2c_recv_len[index] = 1;
+ stm_i2c->cr1 = AO_STM_I2C_CR1;
+
+ /* Clear any pending ADDR bit */
+ stm_i2c->sr2;
+ ao_i2c_wait_addr(index);
+
+ /* Enable interrupts to transfer the byte */
+ stm_i2c->cr2 = (AO_STM_I2C_CR2 |
+ (1 << STM_I2C_CR2_ITEVTEN) |
+ (1 << STM_I2C_CR2_ITERREN) |
+ (1 << STM_I2C_CR2_ITBUFEN));
+ if (stop)
+ stm_i2c->cr1 = AO_STM_I2C_CR1 | (1 << STM_I2C_CR1_STOP);
+
+ ao_arch_block_interrupts();
+ while (ao_i2c_recv_len[index])
+ if (ao_sleep_for(&ao_i2c_recv_len[index], 1))
+ break;
+ ao_arch_release_interrupts();
+ ret = ao_i2c_recv_len[index] == 0;
+ } else {
+ uint8_t rx_dma_index = ao_i2c_stm_info[index].rx_dma_index;
+ ao_dma_set_transfer(rx_dma_index,
+ &stm_i2c->dr,
+ block,
+ len,
+ (0 << STM_DMA_CCR_MEM2MEM) |
+ (STM_DMA_CCR_PL_HIGH << STM_DMA_CCR_PL) |
+ (STM_DMA_CCR_MSIZE_8 << STM_DMA_CCR_MSIZE) |
+ (STM_DMA_CCR_PSIZE_8 << STM_DMA_CCR_PSIZE) |
+ (1 << STM_DMA_CCR_MINC) |
+ (0 << STM_DMA_CCR_PINC) |
+ (0 << STM_DMA_CCR_CIRC) |
+ (STM_DMA_CCR_DIR_PER_TO_MEM << STM_DMA_CCR_DIR));
+
+ /* XXX ao_i2c_recv_dma_isr hasn't ever been used, so it
+ * doesn't appear to be necessary. Testing with a device
+ * that uses i2c would really be useful here to discover
+ * whether this function is necessary or not.
+ */
+#if 0
+ ao_dma_set_isr(rx_dma_index, ao_i2c_recv_dma_isr);
+#else
+ (void) ao_i2c_recv_dma_isr;
+#endif
+ stm_i2c->cr1 = AO_STM_I2C_CR1 | (1 << STM_I2C_CR1_ACK);
+ stm_i2c->cr2 = AO_STM_I2C_CR2 |
+ (1 << STM_I2C_CR2_DMAEN) | (1 << STM_I2C_CR2_LAST);
+ /* Clear any pending ADDR bit */
+ (void) stm_i2c->sr2;
+ ao_i2c_wait_addr(index);
+
+ ao_dma_start(rx_dma_index);
+ ao_arch_block_interrupts();
+ while (!ao_dma_done[rx_dma_index])
+ if (ao_sleep_for(&ao_dma_done[rx_dma_index], len))
+ break;
+ ao_arch_release_interrupts();
+ ret = ao_dma_done[rx_dma_index];
+ ao_dma_done_transfer(rx_dma_index);
+ stm_i2c->cr1 = AO_STM_I2C_CR1 | (1 << STM_I2C_CR1_STOP);
+ }
+ if (stop)
+ ao_i2c_wait_stop(index);
+ return ret;
+}
+
+static void
ao_i2c_channel_init(uint8_t index)
{
struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
+ int i;
/* Turn I2C off while configuring */
+ stm_i2c->cr1 = (1 << STM_I2C_CR1_SWRST);
+ for (i = 0; i < 100; i++)
+ asm("nop");
stm_i2c->cr1 = 0;
stm_i2c->cr2 = AO_STM_I2C_CR2;
stm_i2c->sr1 = 0;
stm_i2c->sr2 = 0;
- stm_i2c->ccr = ((1 << STM_I2C_CCR_FS) |
+ stm_i2c->ccr = ((I2C_FAST << STM_I2C_CCR_FS) |
(0 << STM_I2C_CCR_DUTY) |
- (20 << STM_I2C_CCR_CCR));
-
+ (I2C_CCR_HIGH << STM_I2C_CCR_CCR));
+
+ stm_i2c->trise = I2C_TRISE;
+
stm_i2c->cr1 = AO_STM_I2C_CR1;
}
+static inline void
+i2c_pin_set(struct stm_gpio *gpio, int pin)
+{
+ stm_afr_set(gpio, pin, STM_AFR_AF4);
+ stm_ospeedr_set(gpio, pin, STM_OSPEEDR_400kHz);
+ stm_pupdr_set(gpio, pin, STM_PUPDR_PULL_UP);
+}
+
void
ao_i2c_init(void)
{
stm_rcc.ahbenr |= (1 << STM_RCC_AHBENR_GPIOBEN);
#if HAS_I2C_1
# if I2C_1_PB6_PB7
- stm_afr_set(&stm_gpiob, 6, STM_AFR_AF4);
- stm_afr_set(&stm_gpiob, 7, STM_AFR_AF4);
+ i2c_pin_set(&stm_gpiob, 6);
+ i2c_pin_set(&stm_gpiob, 7);
# else
# if I2C_1_PB8_PB9
- stm_afr_set(&stm_gpiob, 8, STM_AFR_AF4);
- stm_afr_set(&stm_gpiob, 9, STM_AFR_AF4);
+ i2c_pin_set(&stm_gpiob, 8);
+ i2c_pin_set(&stm_gpiob, 9);
# else
# error "No I2C_1 port configuration specified"
# endif
ao_i2c_channel_init(0);
stm_nvic_set_enable(STM_ISR_I2C1_EV_POS);
- stm_nvic_set_priority(STM_ISR_I2C1_EV_POS, 3);
+ stm_nvic_set_priority(STM_ISR_I2C1_EV_POS, AO_STM_NVIC_MED_PRIORITY);
stm_nvic_set_enable(STM_ISR_I2C1_ER_POS);
- stm_nvic_set_priority(STM_ISR_I2C1_ER_POS, 3);
+ stm_nvic_set_priority(STM_ISR_I2C1_ER_POS, AO_STM_NVIC_MED_PRIORITY);
#endif
#if HAS_I2C_2
# if I2C_2_PB10_PB11
- stm_afr_set(&stm_gpiob, 10, STM_AFR_AF4);
- stm_afr_set(&stm_gpiob, 11, STM_AFR_AF4);
+ i2c_pin_set(&stm_gpiob, 10);
+ i2c_pin_set(&stm_gpiob, 11);
# else
# error "No I2C_2 port configuration specified"
# endif
ao_i2c_channel_init(1);
stm_nvic_set_enable(STM_ISR_I2C2_EV_POS);
- stm_nvic_set_priority(STM_ISR_I2C2_EV_POS, 3);
+ stm_nvic_set_priority(STM_ISR_I2C2_EV_POS, AO_STM_NVIC_MED_PRIORITY);
stm_nvic_set_enable(STM_ISR_I2C2_ER_POS);
- stm_nvic_set_priority(STM_ISR_I2C2_ER_POS, 3);
+ stm_nvic_set_priority(STM_ISR_I2C2_ER_POS, AO_STM_NVIC_MED_PRIORITY);
#endif
}
-