sam3: Merge sam4e_spi.c into spi.c

Determine at runtime if the SPI or USART devices should be used.

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

1 files changed, 189 insertions, 38 deletions

diff --git a/src/sam3/spi.c b/src/sam3/spi.c
index a92a766b..0c96baca 100644
--- a/src/sam3/spi.c
+++ b/src/sam3/spi.c
@@ -1,6 +1,8 @@
 // SPI transmissions on sam3
 //
 // Copyright (C) 2018  Petri Honkala <cruwaller@gmail.com>
+// Copyright (C) 2018  Florian Heilmann <Florian.Heilmann@gmx.net>
+// Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
 //
 // This file may be distributed under the terms of the GNU GPLv3 license.
 
@@ -9,54 +11,88 @@
 #include "internal.h" // gpio_peripheral
 #include "sched.h" // sched_shutdown
 
-#define REGPTR     SPI0
-#define PERIPH_ID  ID_SPI0
 
-#define CHANNEL    0 // Use same channel for all
+/****************************************************************
+ * SPI/USART buses and pins
+ ****************************************************************/
+
+struct spi_info {
+    void *dev;
+    uint32_t dev_id;
+    uint8_t miso_pin, mosi_pin, sck_pin, rxtx_periph, sck_periph;
+};
+
+static const struct spi_info spi_bus[] = {
+#if CONFIG_MACH_SAM3X8E
+    { SPI0, ID_SPI0, GPIO('A', 25), GPIO('A', 26), GPIO('A', 27), 'A', 'A' },
+#elif CONFIG_MACH_SAM4E8E
+    { USART0, ID_USART0, GPIO('B', 0), GPIO('B', 1), GPIO('B', 13), 'C', 'C' },
+    { USART1, ID_USART1, GPIO('A', 21), GPIO('A', 22), GPIO('A', 23), 'A', 'A'},
+#endif
+};
+
+static int
+is_spihw(void *dev)
+{
+#if CONFIG_MACH_SAM3X8E
+    return dev == SPI0;
+#else
+    return dev == SPI;
+#endif
+}
 
 static void
-spi_init(void)
+init_pins(uint32_t bus)
 {
-    /* Configure SCK, MISO and MOSI */
-    gpio_peripheral(GPIO('A', 25), 'A', 0); // Arduino 74
-    gpio_peripheral(GPIO('A', 26), 'A', 0); // Arduino 75
-    gpio_peripheral(GPIO('A', 27), 'A', 0); // Arduino 76
+    const struct spi_info *si = &spi_bus[bus];
+    gpio_peripheral(si->sck_pin, si->sck_periph, 0);
+    gpio_peripheral(si->miso_pin, si->rxtx_periph, 1);
+    gpio_peripheral(si->mosi_pin, si->rxtx_periph, 0);
+    enable_pclock(si->dev_id);
+}
 
-    // Enable SPI clocks
-    enable_pclock(PERIPH_ID);
+
+/****************************************************************
+ * SPI hardware
+ ****************************************************************/
+
+#define CHANNEL    0 // Use same channel for all
+
+static void
+spihw_init(uint32_t bus)
+{
+    init_pins(bus);
+    Spi *pSpi = spi_bus[bus].dev;
 
     /* Disable SPI */
-    REGPTR->SPI_CR  = SPI_CR_SPIDIS;
+    pSpi->SPI_CR  = SPI_CR_SPIDIS;
     /* Execute a software reset of the SPI twice */
-    REGPTR->SPI_CR  = SPI_CR_SWRST;
-    REGPTR->SPI_CR  = SPI_CR_SWRST;
+    pSpi->SPI_CR  = SPI_CR_SWRST;
+    pSpi->SPI_CR  = SPI_CR_SWRST;
 
-    REGPTR->SPI_MR = ( SPI_MR_MSTR |       // Set master mode
-                       SPI_MR_MODFDIS |    // Disable fault detection
-                       SPI_MR_PCS(CHANNEL) // Fixes peripheral select
-                     );
-    REGPTR->SPI_IDR = 0xffffffff; // Disable ISRs
+    pSpi->SPI_MR = ( SPI_MR_MSTR |       // Set master mode
+                     SPI_MR_MODFDIS |    // Disable fault detection
+                     SPI_MR_PCS(CHANNEL) // Fixes peripheral select
+                   );
+    pSpi->SPI_IDR = 0xffffffff; // Disable ISRs
 
     /* Clear Chip Select Registers */
-    REGPTR->SPI_CSR[0] = 0;
-    REGPTR->SPI_CSR[1] = 0;
-    REGPTR->SPI_CSR[2] = 0;
-    REGPTR->SPI_CSR[3] = 0;
+    pSpi->SPI_CSR[0] = 0;
+    pSpi->SPI_CSR[1] = 0;
+    pSpi->SPI_CSR[2] = 0;
+    pSpi->SPI_CSR[3] = 0;
 
     /* Set basic channel config */
-    REGPTR->SPI_CSR[CHANNEL] = 0;
+    pSpi->SPI_CSR[CHANNEL] = 0;
     /* Enable SPI */
-    REGPTR->SPI_CR = SPI_CR_SPIEN;
+    pSpi->SPI_CR = SPI_CR_SPIEN;
 }
 
-struct spi_config
-spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
+static struct spi_config
+spihw_setup(uint32_t bus, uint8_t mode, uint32_t rate)
 {
-    if (bus != CHANNEL)
-        shutdown("Invalid spi_setup parameters");
-
     // Make sure bus is enabled
-    spi_init();
+    spihw_init(bus);
 
     uint32_t config = 0;
     uint32_t clockDiv;
@@ -90,20 +126,21 @@ spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
     };
 
     config |= ((clockDiv & 0xffu) << SPI_CSR_SCBR_Pos);
-    return (struct spi_config){.cfg = config};
+    return (struct spi_config){ .spidev = spi_bus[bus].dev, .cfg = config };
 }
 
-void
-spi_prepare(struct spi_config config)
+static void
+spihw_prepare(struct spi_config config)
 {
-    REGPTR->SPI_CSR[CHANNEL] = config.cfg;
+    Spi *pSpi = config.spidev;
+    pSpi->SPI_CSR[CHANNEL] = config.cfg;
 }
 
-void
-spi_transfer(struct spi_config config, uint8_t receive_data
-             , uint8_t len, uint8_t *data)
+static void
+spihw_transfer(struct spi_config config, uint8_t receive_data
+               , uint8_t len, uint8_t *data)
 {
-    Spi* const pSpi = REGPTR;
+    Spi *pSpi = config.spidev;
     if (receive_data) {
         while (len--) {
             pSpi->SPI_TDR = *data;
@@ -124,3 +161,117 @@ spi_transfer(struct spi_config config, uint8_t receive_data
         }
     }
 }
+
+
+/****************************************************************
+ * USART hardware
+ ****************************************************************/
+
+static struct spi_config
+usart_setup(uint32_t bus, uint8_t mode, uint32_t rate)
+{
+    init_pins(bus);
+    Usart *p_usart = spi_bus[bus].dev;
+
+    p_usart->US_MR = 0;
+    p_usart->US_RTOR = 0;
+    p_usart->US_TTGR = 0;
+
+    p_usart->US_CR = US_CR_RSTTX | US_CR_RSTRX | US_CR_TXDIS | US_CR_RXDIS;
+
+    uint32_t br = DIV_ROUND_UP(CHIP_FREQ_CPU_MAX, rate);
+    p_usart->US_BRGR = br << US_BRGR_CD_Pos;
+
+    uint32_t reg = US_MR_CHRL_8_BIT |
+        US_MR_USART_MODE_SPI_MASTER |
+        US_MR_CLKO |
+        US_MR_CHMODE_NORMAL;
+    switch (mode) {
+    case 0:
+        reg |= US_MR_CPHA;
+        reg &= ~US_MR_CPOL;
+        break;
+    case 1:
+        reg &= ~US_MR_CPHA;
+        reg &= ~US_MR_CPOL;
+        break;
+    case 2:
+        reg |= US_MR_CPHA;
+        reg |= US_MR_CPOL;
+        break;
+    case 3:
+        reg &= ~US_MR_CPHA;
+        reg |= US_MR_CPOL;
+        break;
+    }
+
+    p_usart->US_MR |= reg;
+    p_usart->US_CR = US_CR_RXEN | US_CR_TXEN;
+    return (struct spi_config){ .spidev=p_usart, .cfg=p_usart->US_MR };
+}
+
+static void
+usart_prepare(struct spi_config config)
+{
+}
+
+static void
+usart_transfer(struct spi_config config, uint8_t receive_data
+               , uint8_t len, uint8_t *data)
+{
+    Usart *p_usart = config.spidev;
+    if (receive_data) {
+        for (uint32_t i = 0; i < len; ++i) {
+            uint32_t co = (uint32_t)*data & 0x000000FF;
+            while(!(p_usart->US_CSR & US_CSR_TXRDY)) {}
+            p_usart->US_THR = US_THR_TXCHR(co);
+            uint32_t ci = 0;
+            while(!(p_usart->US_CSR & US_CSR_RXRDY)) {}
+            ci = p_usart->US_RHR & US_RHR_RXCHR_Msk;
+            *data++ = (uint8_t)ci;
+        }
+    } else {
+        for (uint32_t i = 0; i < len; ++i) {
+            uint32_t co = (uint32_t)*data & 0x000000FF;
+            while(!(p_usart->US_CSR & US_CSR_TXRDY)) {}
+            p_usart->US_THR = US_THR_TXCHR(co);
+            while(!(p_usart->US_CSR & US_CSR_RXRDY)) {}
+            (void)(p_usart->US_RHR & US_RHR_RXCHR_Msk);
+            (void)*data++;
+        }
+    }
+}
+
+
+/****************************************************************
+ * Interface
+ ****************************************************************/
+
+struct spi_config
+spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
+{
+    if (bus >= ARRAY_SIZE(spi_bus))
+        shutdown("Invalid spi bus");
+    if (is_spihw(spi_bus[bus].dev))
+        return spihw_setup(bus, mode, rate);
+    return usart_setup(bus, mode, rate);
+}
+
+void
+spi_prepare(struct spi_config config)
+{
+    if (is_spihw(config.spidev))
+        spihw_prepare(config);
+    else
+        usart_prepare(config);
+}
+
+void
+spi_transfer(struct spi_config config, uint8_t receive_data
+             , uint8_t len, uint8_t *data)
+{
+    if (is_spihw(config.spidev))
+        spihw_transfer(config, receive_data, len, data);
+    else
+        usart_transfer(config, receive_data, len, data);
+}