cpu/msp430: clean up and fix clock driver

[maribu]

Contribution description

• The validity test for the high frequency crystal did not take into account the higher range supported by the MSP430 F2xx / G2xx family. This fixes the issue.
  • The CPU family used is exposed to C as CPU_FAM_<NAME> macro
• Unused headers where dropped
• The status register is aliased SR, so let's use that more readable name.

Testing procedure

This does not change any binaries. It would allow boards using an MSP430 F2xx/G2xx MCU to configure a CPU frequency of 16 MHz from a crystal without a compile time check triggering. (Both upstream boards use 16 MHz, but from a DCO instead of a crystal.)

One could test this with the following patch:

diff --git a/boards/olimex-msp430-h2618/include/periph_conf.h b/boards/olimex-msp430-h2618/include/periph_conf.h
index 23d223a40b..20b981a6f7 100644
--- a/boards/olimex-msp430-h2618/include/periph_conf.h
+++ b/boards/olimex-msp430-h2618/include/periph_conf.h
@@ -28,19 +28,21 @@
 extern "C" {
 #endif
 
-#define CLOCK_CORECLOCK     msp430_dco_freq
+#define CLOCK_CORECLOCK     MHZ(16)
 
 /**
  * @brief   Clock configuration
  */
 static const msp430_clock_params_t clock_params = {
-    .target_dco_frequency = MHZ(16),
+    .target_dco_frequency = 0,
     .lfxt1_frequency = 32768,
-    .main_clock_source = MAIN_CLOCK_SOURCE_DCOCLK,
-    .submain_clock_source = SUBMAIN_CLOCK_SOURCE_DCOCLK,
+    .main_clock_source = MAIN_CLOCK_SOURCE_XT2CLK,
+    .submain_clock_source = SUBMAIN_CLOCK_SOURCE_XT2CLK,
     .main_clock_divier = MAIN_CLOCK_DIVIDE_BY_1,
     .submain_clock_divier = SUBMAIN_CLOCK_DIVIDE_BY_1,
     .auxiliary_clock_divier = AUXILIARY_CLOCK_DIVIDE_BY_1,
+    .xt2_frequency = CLOCK_CORECLOCK,
+    .has_xt2 = true,
 };
 
 /**

make BOARD=olimex-msp430-h2618 -C examples/default

yields undefined reference to xt2_frequency_invalid'inmaster`, but works with this PR.

Issues/PRs references

None

[riot-ci]

Murdock results

✔️ PASSED

024832a cpu/msp430: clean up and fix clock driver

Success	Failures	Total	Runtime
10066	0	10066	12m:53s

Artifacts

• Documentation preview

[maribu]

Thx :)

[maribu]

IMO this doesn't need a backport, as this bug is not triggered by any boards supported by RIOT. New boards get added to master and won't be backported.