atsamd: Add a get_pclock_frequency() helper function

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

5 files changed, 13 insertions, 7 deletions

diff --git a/src/atsamd/clock.c b/src/atsamd/clock.c
index 1103341a..07dca9d3 100644
--- a/src/atsamd/clock.c
+++ b/src/atsamd/clock.c
@@ -43,6 +43,13 @@ enable_pclock(uint32_t pclk_id, uint32_t pm_id)
     (&PM->APBAMASK.reg)[pm_port] |= pm_bit;
 }
 
+// Return the frequency of the given peripheral clock
+uint32_t
+get_pclock_frequency(uint32_t pclk_id)
+{
+    return FREQ_MAIN;
+}
+
 void
 SystemInit(void)
 {
diff --git a/src/atsamd/i2c.c b/src/atsamd/i2c.c
index 71376322..57374443 100644
--- a/src/atsamd/i2c.c
+++ b/src/atsamd/i2c.c
@@ -4,7 +4,6 @@
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
-#include "autoconf.h" // CONFIG_CLOCK_FREQ
 #include "internal.h" // enable_pclock
 #include "command.h" // shutdown
 #include "gpio.h" // i2c_setup
@@ -38,8 +37,8 @@ i2c_init(void)
                      | SERCOM_I2CM_STATUS_MEXTTOUT
                      | SERCOM_I2CM_CTRLA_MODE_I2C_MASTER);
     si->CTRLA.reg = areg;
-    uint32_t baud = (CONFIG_CLOCK_FREQ / I2C_FREQ
-                     - 10 - CONFIG_CLOCK_FREQ*TIME_RISE/1000000000) / 2;
+    uint32_t freq = get_pclock_frequency(SERCOM3_GCLK_ID_CORE);
+    uint32_t baud = (freq/I2C_FREQ - 10 - freq*TIME_RISE/1000000000) / 2;
     si->BAUD.reg = baud;
     si->CTRLA.reg = areg | SERCOM_I2CM_CTRLA_ENABLE;
     while (si->SYNCBUSY.reg & SERCOM_I2CM_SYNCBUSY_ENABLE)
diff --git a/src/atsamd/internal.h b/src/atsamd/internal.h
index 5606a4ce..2674acc7 100644
--- a/src/atsamd/internal.h
+++ b/src/atsamd/internal.h
@@ -9,6 +9,7 @@
 #define GPIO2BIT(PIN) (1<<((PIN) % 32))
 
 void enable_pclock(uint32_t pclk_id, uint32_t pm_id);
+uint32_t get_pclock_frequency(uint32_t pclk_id);
 void gpio_peripheral(uint32_t gpio, char ptype, int32_t pull_up);
 
 #endif // internal.h
diff --git a/src/atsamd/serial.c b/src/atsamd/serial.c
index e8536b50..81eda46f 100644
--- a/src/atsamd/serial.c
+++ b/src/atsamd/serial.c
@@ -4,7 +4,6 @@
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
-#include "autoconf.h" // CONFIG_SERIAL_BAUD
 #include "board/serial_irq.h" // serial_rx_data
 #include "internal.h" // enable_pclock
 #include "samd21.h" // SERCOM0
@@ -28,7 +27,8 @@ serial_init(void)
                      | SERCOM_USART_CTRLA_RXPO(3));
     su->CTRLA.reg = areg;
     su->CTRLB.reg = SERCOM_USART_CTRLB_TXEN | SERCOM_USART_CTRLB_RXEN;
-    uint32_t baud8 = CONFIG_CLOCK_FREQ / (2 * CONFIG_SERIAL_BAUD);
+    uint32_t freq = get_pclock_frequency(SERCOM0_GCLK_ID_CORE);
+    uint32_t baud8 = freq / (2 * CONFIG_SERIAL_BAUD);
     su->BAUD.reg = (SERCOM_USART_BAUD_FRAC_BAUD(baud8 / 8)
                     | SERCOM_USART_BAUD_FRAC_FP(baud8 % 8));
     NVIC_SetPriority(SERCOM0_IRQn, 0);
diff --git a/src/atsamd/spi.c b/src/atsamd/spi.c
index 9c82de1b..e0860576 100644
--- a/src/atsamd/spi.c
+++ b/src/atsamd/spi.c
@@ -4,7 +4,6 @@
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
-#include "autoconf.h" // CONFIG_CLOCK_FREQ
 #include "internal.h" // enable_pclock
 #include "command.h" // shutdown
 #include "gpio.h" // spi_setup
@@ -47,7 +46,7 @@ spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
                       | SERCOM_SPI_CTRLA_DIPO(0)
                       | SERCOM_SPI_CTRLA_DOPO(1)
                       | SERCOM_SPI_CTRLA_ENABLE);
-    uint32_t baud = CONFIG_CLOCK_FREQ / (2 * rate) - 1;
+    uint32_t baud = get_pclock_frequency(SERCOM4_GCLK_ID_CORE) / (2 * rate) - 1;
     spi_init(ctrla, baud);
     return (struct spi_config){ .ctrla = ctrla, .baud = baud };
 }