lpc176x: Add support for ssp1 (#2393)

Signed-off-by: Andrey Kovalev <aka@pxe.ru>

src/lpc176x/gpio.h

@@ -30,6 +30,7 @@ uint16_t gpio_adc_read(struct gpio_adc g);
 void gpio_adc_cancel_sample(struct gpio_adc g);
 
 struct spi_config {
+    void *spi;
     uint32_t cr0, cpsr;
 };
 struct spi_config spi_setup(uint32_t bus, uint8_t mode, uint32_t rate);

src/lpc176x/internal.h

@@ -10,6 +10,7 @@
 
 #define PCLK_TIMER0 1
 #define PCLK_UART0 3
+#define PCLK_SSP1 10
 #define PCLK_ADC 12
 #define PCLK_I2C1 19
 #define PCLK_SSP0 21

src/lpc176x/spi.c

@@ -9,42 +9,55 @@
 #include "internal.h" // gpio_peripheral
 #include "sched.h" // sched_shutdown
 
+struct spi_info {
+    LPC_SSP_TypeDef *spi;
+    uint8_t miso_pin, mosi_pin, sck_pin, pclk;
+};
+
 DECL_ENUMERATION("spi_bus", "ssp0", 0);
 DECL_CONSTANT_STR("BUS_PINS_ssp0", "P0.17,P0.18,P0.15");
+DECL_ENUMERATION("spi_bus", "ssp1", 1);
+DECL_CONSTANT_STR("BUS_PINS_ssp1", "P0.8,P0.9,P0.7");
+
+static const struct spi_info spi_bus[] = {
+    { LPC_SSP0, GPIO(0, 17), GPIO(0, 18), GPIO(0, 15), PCLK_SSP0 },
+    { LPC_SSP1, GPIO(0, 8), GPIO(0, 9), GPIO(0, 7), PCLK_SSP1 },
+};
 
 static void
-spi_init(void)
+spi_init(uint32_t bus)
 {
-    static int have_run_init;
+    static int have_run_init[ARRAY_SIZE(spi_bus)];
-    if (have_run_init)
+    if (have_run_init[bus])
         return;
-    have_run_init = 1;
+    have_run_init[bus] = 1;
 
     // Configure MISO0, MOSI0, SCK0 pins
-    gpio_peripheral(GPIO(0, 17), 2, 0);
+    gpio_peripheral(spi_bus[bus].miso_pin, 2, 0);
-    gpio_peripheral(GPIO(0, 18), 2, 0);
+    gpio_peripheral(spi_bus[bus].mosi_pin, 2, 0);
-    gpio_peripheral(GPIO(0, 15), 2, 0);
+    gpio_peripheral(spi_bus[bus].sck_pin, 2, 0);
 
     // Setup clock
-    enable_pclock(PCLK_SSP0);
+    enable_pclock(spi_bus[bus].pclk);
 
     // Set initial registers
-    LPC_SSP0->CR0 = 0x07;
+    LPC_SSP_TypeDef *spi = spi_bus[bus].spi;
-    LPC_SSP0->CPSR = 254;
+    spi->CR0 = 0x07;
-    LPC_SSP0->CR1 = 1<<1;
+    spi->CPSR = 254;
+    spi->CR1 = 1<<1;
 }
 
 struct spi_config
 spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
 {
-    if (bus)
+    if (bus >= ARRAY_SIZE(spi_bus))
         shutdown("Invalid spi_setup parameters");
 
     // Make sure bus is enabled
-    spi_init();
+    spi_init(bus);
 
     // Setup clock rate and mode
-    struct spi_config res = {0, 0};
+    struct spi_config res = {spi_bus[bus].spi, 0, 0};
     uint32_t pclk = SystemCoreClock;
     uint32_t div = DIV_ROUND_UP(pclk/2, rate) << 1;
     res.cpsr = div < 2 ? 2 : (div > 254 ? 254 : div);
@@ -56,31 +69,33 @@ spi_setup(uint32_t bus, uint8_t mode, uint32_t rate)
 void
 spi_prepare(struct spi_config config)
 {
-    LPC_SSP0->CR0 = config.cr0;
+    LPC_SSP_TypeDef *spi = config.spi;
-    LPC_SSP0->CPSR = config.cpsr;
+    spi->CR0 = config.cr0;
+    spi->CPSR = config.cpsr;
 }
 
 void
 spi_transfer(struct spi_config config, uint8_t receive_data
              , uint8_t len, uint8_t *data)
 {
+    LPC_SSP_TypeDef *spi = config.spi;
     if (receive_data) {
         while (len--) {
-            LPC_SSP0->DR = *data;
+            spi->DR = *data;
             // wait for read data to be ready
-            while (!(LPC_SSP0->SR & (1<<2)))
+            while (!(spi->SR & (1<<2)))
                 ;
             // get data
-            *data++ = LPC_SSP0->DR;
+            *data++ = spi->DR;
         }
     } else {
         while (len--) {
-            LPC_SSP0->DR = *data++;
+            spi->DR = *data++;
             // wait for read data to be ready
-            while (!(LPC_SSP0->SR & (1<<2)))
+            while (!(spi->SR & (1<<2)))
                 ;
             // read data (to clear receive fifo)
-            LPC_SSP0->DR;
+            spi->DR;
         }
     }
 }