lpc176x: Move ADC code to new adc.c file

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

src/lpc176x/Makefile

@@ -13,7 +13,9 @@ CFLAGS_klipper.elf += -T $(OUT)LPC1768.ld
 CFLAGS_klipper.elf += --specs=nano.specs --specs=nosys.specs
 
 # Add source files
-src-y += lpc176x/main.c lpc176x/timer.c lpc176x/gpio.c lpc176x/i2c.c
+src-y += lpc176x/main.c lpc176x/timer.c lpc176x/gpio.c
+src-$(CONFIG_HAVE_GPIO_ADC) += lpc176x/adc.c
+src-$(CONFIG_HAVE_GPIO_I2C) += lpc176x/i2c.c
 src-$(CONFIG_HAVE_GPIO_SPI) += lpc176x/spi.c
 src-y += generic/crc16_ccitt.c generic/alloc.c
 src-y += generic/armcm_irq.c generic/timer_irq.c

src/lpc176x/adc.c

@@ -0,0 +1,96 @@
+// Analog to digital support on lpc176x
+//
+// Copyright (C) 2018-2019  Kevin O'Connor <kevin@koconnor.net>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "LPC17xx.h" // LPC_PINCON
+#include "autoconf.h" // CONFIG_CLOCK_FREQ
+#include "board/misc.h" // timer_from_us
+#include "command.h" // shutdown
+#include "gpio.h" // gpio_adc_setup
+#include "internal.h" // gpio_peripheral
+#include "sched.h" // sched_shutdown
+
+static const uint8_t adc_pins[] = {
+    GPIO(0, 23), GPIO(0, 24), GPIO(0, 25), GPIO(0, 26),
+    GPIO(1, 30), GPIO(1, 31), GPIO(0, 3), GPIO(0, 2),
+};
+
+static const uint8_t adc_pin_funcs[] = {
+    1, 1, 1, 1, 3, 3, 2, 2
+};
+
+#define ADC_FREQ_MAX 13000000
+DECL_CONSTANT(ADC_MAX, 4095);
+
+struct gpio_adc
+gpio_adc_setup(uint8_t pin)
+{
+    // Find pin in adc_pins table
+    int chan;
+    for (chan=0; ; chan++) {
+        if (chan >= ARRAY_SIZE(adc_pins))
+            shutdown("Not a valid ADC pin");
+        if (adc_pins[chan] == pin)
+            break;
+    }
+
+    uint32_t prescal = DIV_ROUND_UP(CONFIG_CLOCK_FREQ*4, ADC_FREQ_MAX) - 1;
+    uint32_t adcr = (1<<21) | ((prescal & 0xff) << 8);
+    if (!(LPC_SC->PCONP & (1<<PCLK_ADC))) {
+        // Power up ADC
+        enable_peripheral_clock(PCLK_ADC);
+        LPC_ADC->ADCR = adcr;
+    }
+
+    gpio_peripheral(GPIO2PORT(pin), pin % 32, adc_pin_funcs[chan], 0);
+
+    return (struct gpio_adc){ .cmd = adcr | (1 << chan) | (1 << 24) };
+}
+
+static uint32_t adc_status;
+
+// Try to sample a value. Returns zero if sample ready, otherwise
+// returns the number of clock ticks the caller should wait before
+// retrying this function.
+uint32_t
+gpio_adc_sample(struct gpio_adc g)
+{
+    uint32_t status = adc_status;
+    if (status == g.cmd) {
+        // Sample already underway - check if it is ready
+        uint32_t val = LPC_ADC->ADGDR;
+        if (val & (1<<31))
+            // Sample ready
+            return 0;
+        goto need_delay;
+    }
+    if (status)
+        // ADC busy on some other channel
+        goto need_delay;
+
+    // Start new sample
+    adc_status = g.cmd;
+    LPC_ADC->ADCR = g.cmd;
+
+need_delay:
+    return (65 * DIV_ROUND_UP(CONFIG_CLOCK_FREQ*4, ADC_FREQ_MAX)
+            + timer_from_us(10));
+}
+
+// Read a value; use only after gpio_adc_sample() returns zero
+uint16_t
+gpio_adc_read(struct gpio_adc g)
+{
+    adc_status = 0;
+    return (LPC_ADC->ADGDR >> 4) & 0x0fff;
+}
+
+// Cancel a sample that may have been started with gpio_adc_sample()
+void
+gpio_adc_cancel_sample(struct gpio_adc g)
+{
+    if (adc_status == g.cmd)
+        adc_status = 0;
+}

src/lpc176x/gpio.c

@@ -6,9 +6,7 @@
 
 #include <string.h> // ffs
 #include "LPC17xx.h" // LPC_PINCON
-#include "autoconf.h" // CONFIG_CLOCK_FREQ
 #include "board/irq.h" // irq_save
-#include "board/misc.h" // timer_from_us
 #include "command.h" // shutdown
 #include "gpio.h" // gpio_out_setup
 #include "internal.h" // gpio_peripheral
@@ -19,10 +17,6 @@
  * Pin mappings
  ****************************************************************/
 
-#define GPIO(PORT, NUM) ((PORT) * 32 + (NUM))
-#define GPIO2PORT(PIN) ((PIN) / 32)
-#define GPIO2BIT(PIN) (1<<((PIN) % 32))
-
 static LPC_GPIO_TypeDef * const digital_regs[] = {
     LPC_GPIO0, LPC_GPIO1, LPC_GPIO2, LPC_GPIO3, LPC_GPIO4
 };
@@ -160,91 +154,3 @@ gpio_in_read(struct gpio_in g)
     LPC_GPIO_TypeDef *regs = g.regs;
     return !!(regs->FIOPIN & g.bit);
 }
-
-
-/****************************************************************
- * Analog to Digital Converter (ADC) pins
- ****************************************************************/
-
-static const uint8_t adc_pins[] = {
-    GPIO(0, 23), GPIO(0, 24), GPIO(0, 25), GPIO(0, 26),
-    GPIO(1, 30), GPIO(1, 31), GPIO(0, 3), GPIO(0, 2),
-};
-
-static const uint8_t adc_pin_funcs[] = {
-    1, 1, 1, 1, 3, 3, 2, 2
-};
-
-#define ADC_FREQ_MAX 13000000
-DECL_CONSTANT(ADC_MAX, 4095);
-
-struct gpio_adc
-gpio_adc_setup(uint8_t pin)
-{
-    // Find pin in adc_pins table
-    int chan;
-    for (chan=0; ; chan++) {
-        if (chan >= ARRAY_SIZE(adc_pins))
-            shutdown("Not a valid ADC pin");
-        if (adc_pins[chan] == pin)
-            break;
-    }
-
-    uint32_t prescal = DIV_ROUND_UP(CONFIG_CLOCK_FREQ*4, ADC_FREQ_MAX) - 1;
-    uint32_t adcr = (1<<21) | ((prescal & 0xff) << 8);
-    if (!(LPC_SC->PCONP & (1<<PCLK_ADC))) {
-        // Power up ADC
-        enable_peripheral_clock(PCLK_ADC);
-        LPC_ADC->ADCR = adcr;
-    }
-
-    gpio_peripheral(GPIO2PORT(pin), pin % 32, adc_pin_funcs[chan], 0);
-
-    return (struct gpio_adc){ .cmd = adcr | (1 << chan) | (1 << 24) };
-}
-
-static uint32_t adc_status;
-
-// Try to sample a value. Returns zero if sample ready, otherwise
-// returns the number of clock ticks the caller should wait before
-// retrying this function.
-uint32_t
-gpio_adc_sample(struct gpio_adc g)
-{
-    uint32_t status = adc_status;
-    if (status == g.cmd) {
-        // Sample already underway - check if it is ready
-        uint32_t val = LPC_ADC->ADGDR;
-        if (val & (1<<31))
-            // Sample ready
-            return 0;
-        goto need_delay;
-    }
-    if (status)
-        // ADC busy on some other channel
-        goto need_delay;
-
-    // Start new sample
-    adc_status = g.cmd;
-    LPC_ADC->ADCR = g.cmd;
-
-need_delay:
-    return (65 * DIV_ROUND_UP(CONFIG_CLOCK_FREQ*4, ADC_FREQ_MAX)
-            + timer_from_us(10));
-}
-
-// Read a value; use only after gpio_adc_sample() returns zero
-uint16_t
-gpio_adc_read(struct gpio_adc g)
-{
-    adc_status = 0;
-    return (LPC_ADC->ADGDR >> 4) & 0x0fff;
-}
-
-// Cancel a sample that may have been started with gpio_adc_sample()
-void
-gpio_adc_cancel_sample(struct gpio_adc g)
-{
-    if (adc_status == g.cmd)
-        adc_status = 0;
-}

src/lpc176x/internal.h

@@ -2,6 +2,10 @@
 #define __LPC176X_INTERNAL_H
 // Local definitions for lpc176x code
 
+#define GPIO(PORT, NUM) ((PORT) * 32 + (NUM))
+#define GPIO2PORT(PIN) ((PIN) / 32)
+#define GPIO2BIT(PIN) (1<<((PIN) % 32))
+
 #define PCLK_TIMER0 1
 #define PCLK_UART0 3
 #define PCLK_ADC 12