tools: give the driver control over CLKM (for ATmega32U2 boards)

- include/atrf.h (atrf_set_clkm), lib/atrf.c (atrf_set_clkm): set or
  disable CLKM
- lib/driver.h (atrf_set_clkm_generic), lib/atrf.c (atrf_set_clkm_generic):
  generic function to set CLKM without restrictions
- lib/driver.h (struct atrf_driver): added driver operation "set_clkm"
  to set CLKM
- lib/atusb.c (atusb_set_clkm, atusb_driver): restrict CLKM on ATmega32U2
  boards
- atrf-txrx/atrf-txrx.c (init_txrx): use atrf_set_clkm to set CLKM
- atrf-txrx/atrf-txrx.c (init_txrx, main): pass CLKM frequency in MHz
  instead of code point

tools/lib/atrf.c

@@ -149,6 +149,52 @@ int atrf_test_mode(struct atrf_dsc *dsc)
 }
 
 
+int atrf_set_clkm_generic(
+    void (*reg_write)(void *dsc, uint8_t reg, uint8_t value),
+    void *handle, int mhz)
+{
+	uint8_t clkm;
+
+	if (!mhz) {
+		reg_write(handle, REG_TRX_CTRL_0, 0); /* disable CLKM */
+		return 1;
+	}
+	switch (mhz) {
+	case 1:
+		clkm = CLKM_CTRL_1MHz;
+		break;
+	case 2:
+		clkm = CLKM_CTRL_2MHz;
+		break;
+	case 4:
+		clkm = CLKM_CTRL_4MHz;
+		break;
+	case 8:
+		clkm = CLKM_CTRL_8MHz;
+		break;
+	case 16:
+		clkm = CLKM_CTRL_16MHz;
+		break;
+	default:
+		fprintf(stderr, "unsupported CLKM frequency %d MHz\n", mhz);
+		return 0;
+	}
+	reg_write(handle, REG_TRX_CTRL_0,
+	    (PAD_IO_8mA << PAD_IO_CLKM_SHIFT) | clkm);
+	return 1;
+}
+
+
+int atrf_set_clkm(struct atrf_dsc *dsc, int mhz)
+{
+	if (dsc->driver->set_clkm)
+		return dsc->driver->set_clkm(dsc->handle, mhz);
+	else
+		return atrf_set_clkm_generic(dsc->driver->reg_write,
+		    dsc->handle, mhz);
+}
+
+
 void atrf_reg_write(struct atrf_dsc *dsc, uint8_t reg, uint8_t value)
 {
 	dsc->driver->reg_write(dsc->handle, reg, value);

tools/lib/atusb.c

@@ -1,8 +1,8 @@
 /*
  * lib/atusb.c - ATUSB access functions library (USB version)
  *
- * Written 2010 by Werner Almesberger
- * Copyright 2010 Werner Almesberger
+ * Written 2010-2011 by Werner Almesberger
+ * Copyright 2010-2011 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -227,6 +227,48 @@ static int atusb_interrupt(void *dsc)
 }
 
 
+/* ----- CLKM handling ----------------------------------------------------- */
+
+
+/*
+ * ATmega32U2-based boards don't allow disabling CLKM, so we keep it at 8 MHz.
+ * We could accommodate a choice between 8 MHz and 16 MHz, but that's for
+ * later.
+ */
+
+static int atusb_set_clkm(void *dsc, int mhz)
+{
+	usb_dev_handle *dev = dsc;
+	uint8_t ids[3];
+	int res;
+
+	if (error)
+		return 0;
+	res = usb_control_msg(dev, FROM_DEV, ATUSB_ID, 0, 0,
+	    (void *) ids, 3, 1000);
+	if (res < 0) {
+		fprintf(stderr, "ATUSB_ID: %s\n", usb_strerror());
+		error = 1;
+		return 0;
+	}
+	switch (ids[2]) {
+	case HW_TYPE_100813:
+	case HW_TYPE_101216:
+		break;
+	case HW_TYPE_110131:
+		if (mhz == 0 || mhz == 8)
+			return 1;
+		fprintf(stderr, "this board only supports CLKM = 8 MHz\n");
+		return 0;
+	default:
+		fprintf(stderr,
+		    "atusb_set_clkm: unknown hardware type 0x%02x\n", ids[2]);
+		return 0;
+	}
+	return atrf_set_clkm_generic(atusb_reg_write, dsc, mhz);
+}
+
+
 /* ----- driver interface -------------------------------------------------- */
 
 
@@ -239,6 +281,7 @@ struct atrf_driver atusb_driver = {
 	.reset		= atusb_reset,
 	.reset_rf	= atusb_reset_rf,
 	.test_mode	= atusb_test_mode,
+	.set_clkm	= atusb_set_clkm,
 	.reg_write	= atusb_reg_write,
 	.reg_read	= atusb_reg_read,
 	.buf_write	= atusb_buf_write,

tools/lib/driver.h

@@ -1,8 +1,8 @@
 /*
  * lib/driver.h - ATRF driver API
  *
- * Written 2010 by Werner Almesberger
- * Copyright 2010 Werner Almesberger
+ * Written 2010-2011 by Werner Almesberger
+ * Copyright 2010-2011 Werner Almesberger
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@ struct atrf_driver {
 	void (*reset)(void *dsc);
 	void (*reset_rf)(void *dsc);
 	void (*test_mode)(void *dsc);
+	int (*set_clkm)(void *dsc, int mhz);
 	void (*reg_write)(void *dsc, uint8_t reg, uint8_t value);
 	uint8_t (*reg_read)(void *dsc, uint8_t reg);
 	void (*buf_write)(void *dsc, const void *buf, int size);
@@ -33,4 +34,9 @@ struct atrf_driver {
 	int (*interrupt)(void *dsc);
 };
 
+
+int atrf_set_clkm_generic(
+    void (*reg_write)(void *dsc, uint8_t reg, uint8_t value),
+    void *handle, int mhz);
+
 #endif /* !DRIVER_H */