atsamd: Add support for programming SERCOM pins

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

config/example-extras.cfg

@@ -721,6 +721,27 @@
 #   parameter must be provided.
 
 
+# SAMD SERCOM configuration to specify which pins to use on a given SERCOM.
+# One may define one section with the "samd_sercom" prefix per
+# SERCOM available. Each SERCOM must be configured prior to using it as
+# SPI or I2C peripheral. Place this config section above any other section
+# that makes use of SPI or I2C buses.
+#[samd_sercom 0]
+#tx_pin:
+#   MOSI pin for SPI communication, or SDA (data) pin for I2C
+#   communication. The pin must have a valid pinmux configuration
+#   for the given SERCOM peripheral. This parameter must be provided.
+#rx_pin:
+#   MISO pin for SPI communication. This pin is not used for I2C
+#   communication (I2C uses tx_pin for both sending and receiving).
+#   The pin must have a valid pinmux configuration for the given
+#   SERCOM peripheral. This parameter is optional.
+#clk_pin:
+#   CLK pin for SPI communication, or SCL (clock) pin for I2C
+#   communication. The pin must have a valid pinmux configuration
+#   for the given SERCOM peripheral. This parameter must be provided.
+
+
 # Statically configured AD5206 digipots connected via SPI bus (one may
 # define any number of sections with an "ad5206" prefix).
 #[ad5206 my_digipot]

docs/Config_Changes.md

@@ -6,6 +6,9 @@ All dates in this document are approximate.
 
 # Changes
 
+20190228: Users of SPI or I2C on SAMD21 boards must now specify the
+bus pins via a [samd_sercom] config section.
+
 20190224: The bed_shape option has been removed from bed_mesh.  The
 radius option has been renamed to bed_radius.  Users with round beds
 should supply the bed_radius and round_probe_count options.

klippy/extras/samd_sercom.py

@@ -0,0 +1,46 @@
+# SAMD Sercom configuration
+#
+# Copyright (C) 2019  Florian Heilmann <Florian.Heilmann@gmx.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+class SamdSERCOM:
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.name = config.get_name().split()[1]
+        ppins = self.printer.lookup_object("pins")
+        try:
+            int(self.name)
+        except ValueError:
+            raise ppins.error("%s: SERCOM name must be an integer" % (
+                    config.get_name(),))
+
+        self.tx_pin = config.get("tx_pin")
+        self.rx_pin = config.get("rx_pin", None)
+        self.clk_pin = config.get("clk_pin")
+
+        tx_pin_params = ppins.lookup_pin(self.tx_pin)
+        self.mcu = tx_pin_params['chip']
+        self.mcu.add_config_cmd(
+            "set_sercom_pin sercom_id=%s pin_type=%d pin=%s" % (
+                self.name, 0, self.tx_pin))
+
+        clk_pin_params = ppins.lookup_pin(self.clk_pin)
+        if self.mcu is not clk_pin_params['chip']:
+           raise ppins.error("%s: SERCOM pins must be on same mcu" % (
+                    config.get_name(),))
+        self.mcu.add_config_cmd(
+            "set_sercom_pin sercom_id=%s pin_type=%d pin=%s" % (
+                self.name, 2, self.clk_pin))
+
+        if self.rx_pin:
+            rx_pin_params = ppins.lookup_pin(self.rx_pin)
+            if self.mcu is not rx_pin_params['chip']:
+                raise ppins.error("%s: SERCOM pins must be on same mcu" % (
+                    config.get_name(),))
+            self.mcu.add_config_cmd(
+                "set_sercom_pin sercom_id=%s pin_type=%d pin=%s" % (
+                    self.name, 1, self.rx_pin))
+
+def load_config_prefix(config):
+    return SamdSERCOM(config)

src/atsamd/Kconfig

@@ -8,7 +8,7 @@ config ATSAMD_SELECT
     select HAVE_GPIO
     select HAVE_GPIO_ADC
     select HAVE_GPIO_I2C
-    select HAVE_GPIO_SPI if MACH_SAMD21
+    select HAVE_GPIO_SPI
     select HAVE_GPIO_HARD_PWM if MACH_SAMD21
     select HAVE_GPIO_BITBANGING
 
@@ -85,5 +85,9 @@ config SERIAL
     depends on !USBSERIAL
     bool
     default y
+config HAVE_SERCOM
+    depends on HAVE_GPIO_I2C || HAVE_GPIO_SPI
+    bool
+    default y
 
 endif

src/atsamd/Makefile

@@ -27,6 +27,7 @@ src-$(CONFIG_SERIAL) += atsamd/serial.c generic/serial_irq.c
 src-$(CONFIG_HAVE_GPIO_ADC) += atsamd/adc.c
 src-$(CONFIG_HAVE_GPIO_I2C) += atsamd/i2c.c
 src-$(CONFIG_HAVE_GPIO_SPI) += atsamd/spi.c
+src-$(CONFIG_HAVE_SERCOM) += atsamd/sercom.c
 src-$(CONFIG_HAVE_GPIO_HARD_PWM) += atsamd/hard_pwm.c
 src-$(CONFIG_MACH_SAMD21) += atsamd/watchdog.c
 src-$(CONFIG_MACH_SAMD21) += atsamd/clock.c atsamd/timer.c generic/timer_irq.c

src/atsamd/gpio.h

@@ -37,6 +37,7 @@ uint16_t gpio_adc_read(struct gpio_adc g);
 void gpio_adc_cancel_sample(struct gpio_adc g);
 
 struct spi_config {
+    void *ss;
     uint32_t ctrla, baud;
 };
 struct spi_config spi_setup(uint32_t bus, uint8_t mode, uint32_t rate);
@@ -45,6 +46,7 @@ void spi_transfer(struct spi_config config, uint8_t receive_data
                   , uint8_t len, uint8_t *data);
 
 struct i2c_config {
+    void *si;
     uint8_t addr;
 };
 

src/atsamd/i2c.c

@@ -1,5 +1,6 @@
 // i2c support on samd
 //
+// Copyright (C) 2019  Florian Heilmann <Florian.Heilmann@gmx.net>
 // Copyright (C) 2018-2019  Kevin O'Connor <kevin@koconnor.net>
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
@@ -13,22 +14,14 @@
 #define I2C_FREQ 100000
 
 static void
-i2c_init(void)
+i2c_init(uint32_t bus, SercomI2cm *si)
 {
-    static int have_run_init;
+    static int have_run_init[8];
-    if (have_run_init)
+    if (have_run_init[bus])
         return;
-    have_run_init = 1;
+    have_run_init[bus] = 1;
-
-    // Setup clock
-    enable_pclock(SERCOM3_GCLK_ID_CORE, ID_SERCOM3);
-
-    // Configure SDA, SCL pins
-    gpio_peripheral(GPIO('A', 22), 'C', 0);
-    gpio_peripheral(GPIO('A', 23), 'C', 0);
 
     // Configure i2c
-    SercomI2cm *si = &SERCOM3->I2CM;
     si->CTRLA.reg = 0;
     uint32_t areg = (SERCOM_I2CM_CTRLA_LOWTOUTEN
                      | SERCOM_I2CM_CTRLA_INACTOUT(3)
@@ -36,7 +29,7 @@ i2c_init(void)
                      | SERCOM_I2CM_STATUS_MEXTTOUT
                      | SERCOM_I2CM_CTRLA_MODE(5));
     si->CTRLA.reg = areg;
-    uint32_t freq = get_pclock_frequency(SERCOM3_GCLK_ID_CORE);
+    uint32_t freq = sercom_get_pclock_frequency(bus);
     uint32_t baud = (freq/I2C_FREQ - 10 - freq*TIME_RISE/1000000000) / 2;
     si->BAUD.reg = baud;
     si->CTRLA.reg = areg | SERCOM_I2CM_CTRLA_ENABLE;
@@ -52,10 +45,17 @@ i2c_init(void)
 struct i2c_config
 i2c_setup(uint32_t bus, uint32_t rate, uint8_t addr)
 {
-    if (bus)
+#ifdef SERCOM7
+    if (bus > 7)
+#else
+    if (bus > 5)
+#endif
         shutdown("Unsupported i2c bus");
-    i2c_init();
+    Sercom *sercom = sercom_enable_pclock(bus);
-    return (struct i2c_config){ .addr=addr<<1 };
+    sercom_i2c_pins(bus);
+    SercomI2cm *si = &sercom->I2CM;
+    i2c_init(bus, si);
+    return (struct i2c_config){ .si=si, .addr=addr<<1 };
 }
 
 static void
@@ -97,7 +97,7 @@ i2c_stop(SercomI2cm *si)
 void
 i2c_write(struct i2c_config config, uint8_t write_len, uint8_t *write)
 {
-    SercomI2cm *si = &SERCOM3->I2CM;
+    SercomI2cm *si = (SercomI2cm *)config.si;
     i2c_start(si, config.addr);
     while (write_len--)
         i2c_send_byte(si, *write++);

src/atsamd/internal.h

@@ -22,4 +22,9 @@ 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);
 
+Sercom * sercom_enable_pclock(uint32_t sercom_id);
+uint32_t sercom_get_pclock_frequency(uint32_t sercom_id);
+uint32_t sercom_spi_pins(uint32_t sercom_id);
+void sercom_i2c_pins(uint32_t sercom_id);
+
 #endif // internal.h

src/atsamd/sercom.c

@@ -0,0 +1,380 @@
+// Handling of sercom pins
+//
+// Copyright (C) 2019  Florian Heilmann <Florian.Heilmann@gmx.net>
+// Copyright (C) 2019  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "internal.h" // sercom_enable
+#include "command.h" // shutdown
+#include "compiler.h" // ARRAY_SIZE
+#include "sched.h" // sched_shutdown
+
+
+/****************************************************************
+ * Available sercom blocks
+ ****************************************************************/
+
+struct sercom_bus {
+    Sercom *sercom;
+    uint32_t pclk_id, pm_id;
+};
+
+static const struct sercom_bus sercoms[] = {
+    { SERCOM0, SERCOM0_GCLK_ID_CORE, ID_SERCOM0 },
+    { SERCOM1, SERCOM1_GCLK_ID_CORE, ID_SERCOM1 },
+    { SERCOM2, SERCOM2_GCLK_ID_CORE, ID_SERCOM2 },
+    { SERCOM3, SERCOM3_GCLK_ID_CORE, ID_SERCOM3 },
+    { SERCOM4, SERCOM4_GCLK_ID_CORE, ID_SERCOM4 },
+    { SERCOM5, SERCOM5_GCLK_ID_CORE, ID_SERCOM5 },
+#ifdef SERCOM6
+    { SERCOM6, SERCOM6_GCLK_ID_CORE, ID_SERCOM6 },
+    { SERCOM7, SERCOM7_GCLK_ID_CORE, ID_SERCOM7 },
+#endif
+};
+
+Sercom *
+sercom_enable_pclock(uint32_t sercom_id)
+{
+    if (sercom_id >= ARRAY_SIZE(sercoms))
+        shutdown("Invalid sercom bus");
+    const struct sercom_bus *sb = &sercoms[sercom_id];
+    enable_pclock(sb->pclk_id, sb->pm_id);
+    return sb->sercom;
+}
+
+uint32_t
+sercom_get_pclock_frequency(uint32_t sercom_id)
+{
+    const struct sercom_bus *sb = &sercoms[sercom_id];
+    return get_pclock_frequency(sb->pclk_id);
+}
+
+
+/****************************************************************
+ * Pin configurations
+ ****************************************************************/
+
+struct sercom_pad {
+    uint8_t sercom_id, gpio, pad, ptype;
+};
+
+
+static const struct sercom_pad sercom_pads[] = {
+#if CONFIG_MACH_SAMD21
+    { 0, GPIO('A', 8), 0, 'C'},
+    { 0, GPIO('A', 9), 1, 'C'},
+    { 0, GPIO('A', 10), 2, 'C'},
+    { 0, GPIO('A', 11), 3, 'C'},
+    { 0, GPIO('A', 4), 0, 'D'},
+    { 0, GPIO('A', 1), 1, 'D'},
+    { 0, GPIO('A', 6), 2, 'D'},
+    { 0, GPIO('A', 7), 3, 'D'},
+    { 1, GPIO('A', 16), 0, 'C'},
+    { 1, GPIO('A', 17), 1, 'C'},
+    { 1, GPIO('A', 18), 2, 'C'},
+    { 1, GPIO('A', 19), 3, 'C'},
+    { 1, GPIO('A', 0), 0, 'D'},
+    { 1, GPIO('A', 1), 1, 'D'},
+    { 1, GPIO('A', 30), 2, 'D'},
+    { 1, GPIO('A', 31), 3, 'D'},
+    { 2, GPIO('A', 12), 0, 'C'},
+    { 2, GPIO('A', 13), 1, 'C'},
+    { 2, GPIO('A', 14), 2, 'C'},
+    { 2, GPIO('A', 15), 3, 'C'},
+    { 2, GPIO('A', 8), 0, 'D'},
+    { 2, GPIO('A', 9), 1, 'D'},
+    { 2, GPIO('A', 10), 2, 'D'},
+    { 2, GPIO('A', 11), 3, 'D'},
+    { 3, GPIO('A', 22), 0, 'C'},
+    { 3, GPIO('A', 23), 1, 'C'},
+    { 3, GPIO('A', 24), 2, 'C'},
+    { 3, GPIO('A', 25), 3, 'C'},
+    { 3, GPIO('A', 16), 0, 'D'},
+    { 3, GPIO('A', 17), 1, 'D'},
+    { 3, GPIO('A', 18), 2, 'D'},
+    { 3, GPIO('A', 19), 3, 'D'},
+    { 3, GPIO('A', 20), 2, 'D'},
+    { 3, GPIO('A', 21), 3, 'D'},
+    { 4, GPIO('B', 12), 0, 'C'},
+    { 4, GPIO('B', 13), 1, 'C'},
+    { 4, GPIO('B', 14), 2, 'C'},
+    { 4, GPIO('B', 15), 3, 'C'},
+    { 4, GPIO('B', 8), 0, 'D'},
+    { 4, GPIO('B', 9), 1, 'D'},
+    { 4, GPIO('B', 10), 2, 'D'},
+    { 4, GPIO('B', 11), 3, 'D'},
+    { 4, GPIO('A', 12), 0, 'D'},
+    { 4, GPIO('A', 13), 1, 'D'},
+    { 4, GPIO('A', 14), 2, 'D'},
+    { 4, GPIO('A', 15), 3, 'D'},
+    { 5, GPIO('B', 16), 0, 'C'},
+    { 5, GPIO('B', 17), 1, 'C'},
+    { 5, GPIO('A', 20), 2, 'C'},
+    { 5, GPIO('A', 21), 3, 'C'},
+    { 5, GPIO('A', 22), 0, 'D'},
+    { 5, GPIO('A', 23), 1, 'D'},
+    { 5, GPIO('A', 24), 2, 'D'},
+    { 5, GPIO('A', 25), 3, 'D'},
+    { 5, GPIO('B', 30), 0, 'D'},
+    { 5, GPIO('B', 31), 1, 'D'},
+    { 5, GPIO('B', 22), 2, 'D'},
+    { 5, GPIO('B', 23), 3, 'D'},
+    { 5, GPIO('B', 2), 0, 'D'},
+    { 5, GPIO('B', 3), 1, 'D'},
+    { 5, GPIO('B', 0), 2, 'D'},
+    { 5, GPIO('B', 1), 3, 'D'},
+#elif CONFIG_MACH_SAMD51
+    { 0, GPIO('A', 8), 0, 'C'},
+    { 0, GPIO('A', 9), 1, 'C'},
+    { 0, GPIO('A', 10), 2, 'C'},
+    { 0, GPIO('A', 11), 3, 'C'},
+    { 0, GPIO('B', 24), 0, 'C'},
+    { 0, GPIO('B', 25), 1, 'C'},
+    { 0, GPIO('C', 24), 2, 'C'},
+    { 0, GPIO('C', 25), 3, 'C'},
+    { 0, GPIO('A', 4), 0, 'D'},
+    { 0, GPIO('A', 5), 1, 'D'},
+    { 0, GPIO('A', 6), 2, 'D'},
+    { 0, GPIO('A', 7), 3, 'D'},
+    { 0, GPIO('C', 17), 0, 'D'},
+    { 0, GPIO('C', 16), 1, 'D'},
+    { 0, GPIO('C', 18), 2, 'D'},
+    { 0, GPIO('C', 19), 3, 'D'},
+
+    { 1, GPIO('A', 16), 0, 'C'},
+    { 1, GPIO('A', 17), 1, 'C'},
+    { 1, GPIO('A', 18), 2, 'C'},
+    { 1, GPIO('A', 19), 3, 'C'},
+    { 1, GPIO('C', 22), 0, 'C'},
+    { 1, GPIO('C', 23), 1, 'C'},
+    { 1, GPIO('D', 20), 2, 'C'},
+    { 1, GPIO('D', 21), 3, 'C'},
+    { 1, GPIO('C', 27), 0, 'C'},
+    { 1, GPIO('C', 28), 1, 'C'},
+    { 1, GPIO('B', 22), 2, 'C'},
+    { 1, GPIO('B', 23), 3, 'C'},
+    { 1, GPIO('A', 0), 0, 'D'},
+    { 1, GPIO('A', 1), 1, 'D'},
+    { 1, GPIO('A', 30), 2, 'D'},
+    { 1, GPIO('A', 31), 3, 'D'},
+
+    { 2, GPIO('A', 12), 0, 'C'},
+    { 2, GPIO('A', 13), 1, 'C'},
+    { 2, GPIO('A', 14), 2, 'C'},
+    { 2, GPIO('A', 15), 3, 'C'},
+    { 2, GPIO('B', 26), 0, 'C'},
+    { 2, GPIO('B', 27), 1, 'C'},
+    { 2, GPIO('B', 28), 2, 'C'},
+    { 2, GPIO('B', 29), 3, 'C'},
+    { 2, GPIO('A', 9), 0, 'D'},
+    { 2, GPIO('A', 8), 1, 'D'},
+    { 2, GPIO('A', 10), 2, 'D'},
+    { 2, GPIO('A', 11), 3, 'D'},
+    { 2, GPIO('B', 25), 0, 'D'},
+    { 2, GPIO('B', 24), 1, 'D'},
+    { 2, GPIO('C', 24), 2, 'D'},
+    { 2, GPIO('C', 25), 3, 'D'},
+
+    { 3, GPIO('A', 22), 0, 'C'},
+    { 3, GPIO('A', 23), 1, 'C'},
+    { 3, GPIO('A', 24), 2, 'C'},
+    { 3, GPIO('A', 25), 3, 'C'},
+    { 3, GPIO('B', 20), 0, 'C'},
+    { 3, GPIO('B', 21), 1, 'C'},
+    { 3, GPIO('A', 20), 2, 'D'},
+    { 3, GPIO('A', 21), 3, 'D'},
+    { 3, GPIO('A', 17), 0, 'D'},
+    { 3, GPIO('A', 16), 1, 'D'},
+    { 3, GPIO('A', 18), 2, 'D'},
+    { 3, GPIO('A', 19), 3, 'D'},
+    { 3, GPIO('C', 23), 0, 'D'},
+    { 3, GPIO('C', 22), 1, 'D'},
+    { 3, GPIO('D', 20), 2, 'D'},
+    { 3, GPIO('D', 21), 3, 'D'},
+
+    { 4, GPIO('B', 12), 0, 'C'},
+    { 4, GPIO('B', 13), 1, 'C'},
+    { 4, GPIO('B', 14), 2, 'C'},
+    { 4, GPIO('B', 15), 3, 'C'},
+    { 4, GPIO('B', 8), 0, 'D'},
+    { 4, GPIO('B', 9), 1, 'D'},
+    { 4, GPIO('B', 10), 2, 'D'},
+    { 4, GPIO('B', 11), 3, 'D'},
+    { 4, GPIO('A', 13), 0, 'D'},
+    { 4, GPIO('A', 12), 1, 'D'},
+    { 4, GPIO('A', 14), 2, 'D'},
+    { 4, GPIO('A', 15), 3, 'D'},
+    { 4, GPIO('B', 27), 0, 'D'},
+    { 4, GPIO('B', 26), 1, 'D'},
+    { 4, GPIO('B', 28), 2, 'D'},
+    { 4, GPIO('B', 29), 3, 'D'},
+
+    { 5, GPIO('B', 16), 0, 'C'},
+    { 5, GPIO('B', 17), 1, 'C'},
+    { 5, GPIO('B', 18), 2, 'C'},
+    { 5, GPIO('B', 19), 3, 'C'},
+    { 5, GPIO('A', 23), 0, 'D'},
+    { 5, GPIO('A', 22), 1, 'D'},
+    { 5, GPIO('A', 20), 2, 'D'},
+    { 5, GPIO('A', 21), 3, 'D'},
+    { 5, GPIO('A', 24), 2, 'D'},
+    { 5, GPIO('A', 25), 3, 'D'},
+    { 5, GPIO('B', 22), 2, 'D'},
+    { 5, GPIO('B', 23), 3, 'D'},
+    { 5, GPIO('B', 31), 0, 'D'},
+    { 5, GPIO('B', 30), 1, 'D'},
+    { 5, GPIO('B', 0), 2, 'D'},
+    { 5, GPIO('B', 1), 3, 'D'},
+    { 5, GPIO('B', 2), 0, 'D'},
+    { 5, GPIO('B', 3), 1, 'D'},
+  #ifdef SERCOM6
+    { 6, GPIO('C', 16), 0, 'C'},
+    { 6, GPIO('C', 17), 1, 'C'},
+    { 6, GPIO('C', 18), 2, 'C'},
+    { 6, GPIO('C', 19), 3, 'C'},
+    { 6, GPIO('C', 4), 0, 'C'},
+    { 6, GPIO('C', 5), 1, 'C'},
+    { 6, GPIO('C', 6), 2, 'C'},
+    { 6, GPIO('C', 7), 3, 'C'},
+    { 6, GPIO('D', 9), 0, 'D'},
+    { 6, GPIO('D', 8), 1, 'D'},
+    { 6, GPIO('D', 10), 2, 'D'},
+    { 6, GPIO('D', 11), 3, 'D'},
+    { 6, GPIO('C', 13), 0, 'D'},
+    { 6, GPIO('C', 12), 1, 'D'},
+    { 6, GPIO('C', 14), 2, 'D'},
+    { 6, GPIO('C', 15), 3, 'D'},
+    { 6, GPIO('C', 10), 2, 'C'},
+    { 6, GPIO('C', 11), 3, 'C'},
+
+    { 7, GPIO('C', 12), 0, 'C'},
+    { 7, GPIO('C', 13), 1, 'C'},
+    { 7, GPIO('C', 14), 2, 'C'},
+    { 7, GPIO('C', 15), 3, 'C'},
+    { 7, GPIO('D', 8), 0, 'C'},
+    { 7, GPIO('D', 9), 1, 'C'},
+    { 7, GPIO('D', 10), 2, 'C'},
+    { 7, GPIO('D', 11), 3, 'C'},
+    { 7, GPIO('C', 10), 2, 'D'},
+    { 7, GPIO('C', 11), 3, 'D'},
+    { 7, GPIO('B', 21), 0, 'D'},
+    { 7, GPIO('B', 20), 1, 'D'},
+    { 7, GPIO('B', 18), 2, 'D'},
+    { 7, GPIO('B', 19), 3, 'D'},
+    { 7, GPIO('B', 30), 0, 'C'},
+    { 7, GPIO('B', 31), 1, 'C'},
+    { 7, GPIO('A', 30), 2, 'C'},
+    { 7, GPIO('A', 31), 3, 'C'},
+  #endif
+#endif
+};
+
+static const struct sercom_pad *
+sercom_lookup_pad(uint32_t sercom_id, uint8_t pin)
+{
+    const struct sercom_pad *sp = sercom_pads;
+    for (; ; sp++) {
+        if (sp >= &sercom_pads[ARRAY_SIZE(sercom_pads)])
+            shutdown("Invalid SERCOM configuration");
+        if (sp->sercom_id == sercom_id && sp->gpio == pin)
+            return sp;
+    }
+}
+
+
+/****************************************************************
+ * Runtime configuration
+ ****************************************************************/
+
+enum { TX_PIN, RX_PIN, CLK_PIN };
+
+// Runtime configuration
+struct sercom_pin {
+    uint8_t pins[3];
+};
+
+static struct sercom_pin sercom_pins[ARRAY_SIZE(sercoms)];
+
+void
+command_set_sercom_pin(uint32_t *args)
+{
+    uint8_t sercom_id = args[0], pin_type = args[1], pin = args[2];
+    if (sercom_id >= ARRAY_SIZE(sercom_pins)
+        || pin_type >= ARRAY_SIZE(sercom_pins[0].pins))
+        shutdown("Invalid SERCOM bus");
+    sercom_pins[sercom_id].pins[pin_type] = pin;
+}
+DECL_COMMAND(command_set_sercom_pin,
+             "set_sercom_pin sercom_id=%u pin_type=%u pin=%u");
+
+
+/****************************************************************
+ * SPI dopo flag mapping
+ ****************************************************************/
+
+struct sercom_spi_map {
+    uint8_t tx_pad, clk_pad, dopo;
+};
+
+
+static const struct sercom_spi_map sercom_spi[] = {
+    { 0, 1, 0 },
+    { 3, 1, 2 },
+#if CONFIG_MACH_SAMD21
+    { 2, 3, 1 },
+    { 0, 3, 3 },
+#endif
+};
+
+static uint8_t
+sercom_lookup_spi_dopo(uint8_t tx_pad, uint8_t clk_pad)
+{
+    const struct sercom_spi_map *sm = sercom_spi;
+    for (; ; sm++) {
+        if (sm >= &sercom_spi[ARRAY_SIZE(sercom_spi)])
+            shutdown("Invalid combination of TX pin and CLK pin");
+        if (sm->tx_pad == tx_pad && sm->clk_pad == clk_pad)
+            return sm->dopo;
+    }
+}
+
+
+/****************************************************************
+ * Pin setup
+ ****************************************************************/
+
+uint32_t
+sercom_spi_pins(uint32_t sercom_id)
+{
+    uint8_t tx_pin = sercom_pins[sercom_id].pins[TX_PIN];
+    const struct sercom_pad *tx_sp = sercom_lookup_pad(sercom_id, tx_pin);
+    uint8_t rx_pin = sercom_pins[sercom_id].pins[RX_PIN];
+    const struct sercom_pad *rx_sp = sercom_lookup_pad(sercom_id, rx_pin);
+    uint8_t clk_pin = sercom_pins[sercom_id].pins[CLK_PIN];
+    const struct sercom_pad *clk_sp = sercom_lookup_pad(sercom_id, clk_pin);
+
+    uint8_t dopo = sercom_lookup_spi_dopo(tx_sp->pad, clk_sp->pad);
+    if (rx_sp->pad == tx_sp->pad || rx_sp->pad == clk_sp->pad)
+            shutdown("Sercom RX pad collides with TX or CLK pad");
+
+    gpio_peripheral(tx_pin, tx_sp->ptype, 0);
+    gpio_peripheral(rx_pin, rx_sp->ptype, 0);
+    gpio_peripheral(clk_pin, clk_sp->ptype, 0);
+    return SERCOM_SPI_CTRLA_DIPO(rx_sp->pad) | SERCOM_SPI_CTRLA_DOPO(dopo);
+}
+
+void
+sercom_i2c_pins(uint32_t sercom_id)
+{
+    uint8_t tx_pin = sercom_pins[sercom_id].pins[TX_PIN];
+    const struct sercom_pad *tx_sp = sercom_lookup_pad(sercom_id, tx_pin);
+    uint8_t clk_pin = sercom_pins[sercom_id].pins[CLK_PIN];
+    const struct sercom_pad *clk_sp = sercom_lookup_pad(sercom_id, clk_pin);
+
+    if (tx_sp->pad != 0 || clk_sp->pad != 1)
+        shutdown("TX pin not on PAD0 or CLK pin not on PAD1");
+
+    gpio_peripheral(tx_pin, tx_sp->ptype, 0);
+    gpio_peripheral(clk_pin, clk_sp->ptype, 0);
+}

src/atsamd/spi.c

@@ -1,5 +1,6 @@
 // spi support on samd
 //
+// Copyright (C) 2019  Florian Heilmann <Florian.Heilmann@gmx.net>
 // Copyright (C) 2018-2019  Kevin O'Connor <kevin@koconnor.net>
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
@@ -9,24 +10,14 @@
 #include "gpio.h" // spi_setup
 #include "sched.h" // sched_shutdown
 
-static void
+void
-spi_init(uint32_t ctrla, uint32_t baud)
+spi_init(uint32_t bus, SercomSpi *ss, uint32_t ctrla, uint32_t baud)
 {
-    static int have_run_init;
+    static int have_run_init[8];
-    if (have_run_init)
+    if (have_run_init[bus])
         return;
-    have_run_init = 1;
+    have_run_init[bus] = 1;
 
-    // Setup clock
-    enable_pclock(SERCOM4_GCLK_ID_CORE, ID_SERCOM4);
-
-    // Configure MISO, MOSI, SCK pins
-    gpio_peripheral(GPIO('A', 12), 'D', 0);
-    gpio_peripheral(GPIO('B', 10), 'D', 0);
-    gpio_peripheral(GPIO('B', 11), 'D', 0);
-
-    // Configure spi
-    SercomSpi *ss = &SERCOM4->SPI;
     ss->CTRLA.reg = 0;
     ss->CTRLA.reg = ctrla & ~SERCOM_SPI_CTRLA_ENABLE;
     ss->CTRLB.reg = SERCOM_SPI_CTRLB_RXEN;
@@ -37,24 +28,30 @@ spi_init(uint32_t ctrla, uint32_t baud)
 struct spi_config
 spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
 {
-    if (bus)
+#ifdef SERCOM7
+    if (bus > 7)
+#else
+    if (bus > 5)
+#endif
         shutdown("Invalid spi bus");
 
+    uint32_t dipo_dopo = sercom_spi_pins(bus);
     uint32_t ctrla = (SERCOM_SPI_CTRLA_MODE(3)
                       | (mode << SERCOM_SPI_CTRLA_CPHA_Pos)
-                      | SERCOM_SPI_CTRLA_DIPO(0)
+                      | dipo_dopo
-                      | SERCOM_SPI_CTRLA_DOPO(1)
                       | SERCOM_SPI_CTRLA_ENABLE);
-    uint32_t baud = get_pclock_frequency(SERCOM4_GCLK_ID_CORE) / (2 * rate) - 1;
+    Sercom *sercom = sercom_enable_pclock(bus);
-    spi_init(ctrla, baud);
+    SercomSpi *ss = &sercom->SPI;
-    return (struct spi_config){ .ctrla = ctrla, .baud = baud };
+    uint32_t baud = sercom_get_pclock_frequency(bus) / (2 * rate) - 1;
+    spi_init(bus, ss, ctrla, baud);
+    return (struct spi_config){ .ss = ss, .ctrla = ctrla, .baud = baud };
 }
 
 void
 spi_prepare(struct spi_config config)
 {
     uint32_t ctrla = config.ctrla, baud = config.baud;
-    SercomSpi *ss = &SERCOM4->SPI;
+    SercomSpi *ss = (SercomSpi *)config.ss;
     if (ctrla == ss->CTRLA.reg && baud == ss->BAUD.reg)
         return;
     ss->CTRLA.reg = ctrla & ~SERCOM_SPI_CTRLA_ENABLE;
@@ -67,7 +64,7 @@ void
 spi_transfer(struct spi_config config, uint8_t receive_data
              , uint8_t len, uint8_t *data)
 {
-    SercomSpi *ss = &SERCOM4->SPI;
+    SercomSpi *ss = (SercomSpi *)config.ss;
     if (receive_data) {
         while (len--) {
             ss->DATA.reg = *data;