--- /dev/null
+/*
+ * Copyright © 2012 Keith Packard <keithp@keithp.com>
+ *
+ * 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; 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+
+struct ao_i2c_stm_info {
+ uint8_t tx_dma_index;
+ uint8_t rx_dma_index;
+ 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 uint8_t ao_i2c_state[STM_NUM_I2C];
+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
+
+#define AO_STM_I2C_CR2_FREQ (AO_APB1CLK / 1000000)
+
+#define AO_STM_I2C_CR1 ((0 << STM_I2C_CR1_SWRST) | \
+ (0 << STM_I2C_CR1_ALERT) | \
+ (0 << STM_I2C_CR1_PEC) | \
+ (0 << STM_I2C_CR1_POS) | \
+ (0 << STM_I2C_CR1_ACK) | \
+ (0 << STM_I2C_CR1_STOP) | \
+ (0 << STM_I2C_CR1_START) | \
+ (0 << STM_I2C_CR1_NOSTRETCH) | \
+ (0 << STM_I2C_CR1_ENGC) | \
+ (0 << STM_I2C_CR1_ENPEC) | \
+ (0 << STM_I2C_CR1_ENARP) | \
+ (0 << STM_I2C_CR1_SMBTYPE) | \
+ (0 << STM_I2C_CR1_SMBUS) | \
+ (1 << STM_I2C_CR1_PE))
+
+#define AO_STM_I2C_CR2 ((0 << STM_I2C_CR2_LAST) | \
+ (0 << STM_I2C_CR2_DMAEN) | \
+ (0 << STM_I2C_CR2_ITBUFEN) | \
+ (0 << STM_I2C_CR2_ITEVTEN) | \
+ (0 << STM_I2C_CR2_ITERREN) | \
+ (AO_STM_I2C_CR2_FREQ << STM_I2C_CR2_FREQ))
+
+static const struct ao_i2c_stm_info ao_i2c_stm_info[STM_NUM_I2C] = {
+ {
+ .tx_dma_index = STM_DMA_INDEX(STM_DMA_CHANNEL_I2C1_TX),
+ .rx_dma_index = STM_DMA_INDEX(STM_DMA_CHANNEL_I2C1_RX),
+ .stm_i2c = &stm_i2c1
+ },
+ {
+ .tx_dma_index = STM_DMA_INDEX(STM_DMA_CHANNEL_I2C2_TX),
+ .rx_dma_index = STM_DMA_INDEX(STM_DMA_CHANNEL_I2C2_RX),
+ .stm_i2c = &stm_i2c2
+ },
+};
+
+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)) {
+ 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); }
+void stm_i2c2_ev_isr(void) { ao_i2c_ev_isr(1); }
+
+static void
+ao_i2c_er_isr(uint8_t index)
+{
+ struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
+ uint32_t sr1;
+
+ sr1 = stm_i2c->sr1;
+ if (sr1 & (1 << STM_I2C_SR1_AF)) {
+ ao_i2c_state[index] = I2C_ERROR;
+ stm_i2c->sr1 = sr1 & ~(1UL << STM_I2C_SR1_AF);
+ ao_wakeup(&ao_i2c_state[index]);
+ }
+}
+
+void stm_i2c1_er_isr(void) { ao_i2c_er_isr(0); }
+void stm_i2c2_er_isr(void) { ao_i2c_er_isr(1); }
+
+void
+ao_i2c_get(uint8_t index)
+{
+ struct stm_i2c *stm_i2c = ao_i2c_stm_info[index].stm_i2c;
+ ao_mutex_get(&ao_i2c_mutex[index]);
+
+ stm_i2c->sr1 = 0;
+ stm_i2c->sr2 = 0;
+}
+
+void
+ao_i2c_put(uint8_t index)
+{
+ ao_mutex_put(&ao_i2c_mutex[index]);
+}
+
+uint8_t
+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;
+ stm_i2c->cr1 = AO_STM_I2C_CR1 | (1 << STM_I2C_CR1_START);
+ 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;
+}
+
+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;
+ uint8_t rx_dma_index = ao_i2c_stm_info[index].rx_dma_index;
+
+ /* Clear any pending ADDR bit */
+ (void) stm_i2c->sr2;
+ ao_i2c_wait_addr(index);
+ ao_dma_set_transfer(tx_dma_index,
+ &stm_i2c->dr,
+ block,
+ len,
+ (0 << STM_DMA_CCR_MEM2MEM) |
+ (STM_DMA_CCR_PL_MEDIUM << 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_MEM_TO_PER << STM_DMA_CCR_DIR));
+ ao_dma_mutex_get(rx_dma_index);
+ stm_i2c->cr2 = AO_STM_I2C_CR2 | (1 << STM_I2C_CR2_DMAEN);
+
+ ao_dma_start(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;
+ 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);
+ }
+ ao_dma_mutex_put(rx_dma_index);
+ ao_dma_done_transfer(tx_dma_index);
+ return true;
+}
+
+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 tx_dma_index = ao_i2c_stm_info[index].tx_dma_index;
+ uint8_t rx_dma_index = ao_i2c_stm_info[index].rx_dma_index;
+ ao_dma_mutex_get(tx_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];
+ stm_i2c->cr1 = AO_STM_I2C_CR1 | (1 << STM_I2C_CR1_STOP);
+ ao_dma_done_transfer(rx_dma_index);
+ ao_dma_mutex_put(tx_dma_index);
+ }
+ 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;
+
+ (void) stm_i2c->sr1;
+ (void) stm_i2c->sr2;
+ (void) stm_i2c->dr;
+
+ stm_i2c->sr1 = 0;
+ stm_i2c->sr2 = 0;
+
+ stm_i2c->ccr = ((I2C_FAST << STM_I2C_CCR_FS) |
+ (0 << STM_I2C_CCR_DUTY) |
+ (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)
+{
+ ao_enable_port(gpio);
+ stm_gpio_conf(gpio, pin,
+ STM_GPIO_CR_MODE_OUTPUT_2MHZ,
+ STM_GPIO_CR_CNF_OUTPUT_AF_OPEN_DRAIN);
+}
+
+void
+ao_i2c_init(void)
+{
+#if HAS_I2C_1
+# if I2C_1_PB6_PB7
+ stm_set_afio_mapr(STM_AFIO_MAPR_I2C1_REMAP,
+ STM_AFIO_MAPR_I2C1_REMAP_PB6_PB7,
+ STM_AFIO_MAPR_I2C1_REMAP_MASK);
+ i2c_pin_set(&stm_gpiob, 6);
+ i2c_pin_set(&stm_gpiob, 7);
+# else
+# if I2C_1_PB8_PB9
+ stm_set_afio_mapr(STM_AFIO_MAPR_I2C1_REMAP,
+ STM_AFIO_MAPR_I2C1_REMAP_PB8_PB9,
+ STM_AFIO_MAPR_I2C1_REMAP_MASK);
+ i2c_pin_set(&stm_gpiob, 8);
+ i2c_pin_set(&stm_gpiob, 9);
+# else
+# error "No I2C_1 port configuration specified"
+# endif
+# endif
+
+ stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_I2C1EN);
+ ao_i2c_channel_init(0);
+
+ stm_nvic_set_enable(STM_ISR_I2C1_EV_POS);
+ 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, AO_STM_NVIC_MED_PRIORITY);
+#endif
+
+#if HAS_I2C_2
+# if I2C_2_PB10_PB11
+ i2c_pin_set(&stm_gpiob, 10);
+ i2c_pin_set(&stm_gpiob, 11);
+# else
+# error "No I2C_2 port configuration specified"
+# endif
+ stm_rcc.apb1enr |= (1 << STM_RCC_APB1ENR_I2C2EN);
+ ao_i2c_channel_init(1);
+
+ stm_nvic_set_enable(STM_ISR_I2C2_EV_POS);
+ 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, AO_STM_NVIC_MED_PRIORITY);
+#endif
+}
projects / fw / altos / blobdiff