mimxrt: Implement the review comments.

robert-hh · robert-hh · commit 46565d09c8d9 · 2022-09-08T12:26:38.000+02:00
diff --git a/docs/mimxrt/quickref.rst b/docs/mimxrt/quickref.rst
@@ -303,13 +303,16 @@ rates (up to 30Mhz).  Hardware SPI is accessed via the
 
     from machine import SPI, Pin
 
+    spi = SPI(0, 10000000)
     cs_pin = Pin(6, Pin.OUT, value=1)
+    cs_pin(0)
     spi.write('Hello World')
+    cs_pin(1)
 
 For the assignment of Pins to SPI signals, refer to
 :ref:`Hardware SPI pinout <mimxrt_spi_pinout>`.
 The keyword option cs=n can be used to enable the cs pin 0 or 1 for an automatic cs signal. The
-default is cs=0. Using cs=-1 the automatic cs signal is not created. 
+default is cs=-1. Using cs=-1 the automatic cs signal is not created. 
 In that case, cs has to be set by the script. Clearing that assignment requires a power cycle.
 
 Notes:
diff --git a/ports/mimxrt/machine_spi.c b/ports/mimxrt/machine_spi.c
@@ -131,7 +131,7 @@ mp_obj_t machine_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n
         { MP_QSTR_firstbit, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_FIRSTBIT} },
         { MP_QSTR_gap_ns,   MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_drive,    MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = DEFAULT_SPI_DRIVE} },
-        { MP_QSTR_cs,       MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_cs,       MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
     };
 
     // Parse the arguments.
@@ -174,7 +174,9 @@ mp_obj_t machine_spi_make_new(const mp_obj_type_t *type, size_t n_args, size_t n
     self->master_config->lastSckToPcsDelayInNanoSec = self->master_config->betweenTransferDelayInNanoSec;
     self->master_config->pcsToSckDelayInNanoSec = self->master_config->betweenTransferDelayInNanoSec;
     int8_t cs = args[ARG_cs].u_int;
-    // The default value 0 is set already, so only cs=1 has to be set.
+    // In the SPI master_config for automatic CS the value cs=0 is set already,
+    // so only cs=1 has to be addressed here. The case cs == -1 for manual CS is handled
+    // in the function spi_set_iomux() and the value in the master_config can stay at 0.
     if (cs == 1) {
         self->master_config->whichPcs = cs;
     }
diff --git a/ports/mimxrt/machine_uart.c b/ports/mimxrt/machine_uart.c
@@ -438,7 +438,7 @@ STATIC mp_uint_t machine_uart_ioctl(mp_obj_t self_in, mp_uint_t request, mp_uint
                 ret |= MP_STREAM_POLL_RD;
             }
         }
-        if ((flags & MP_STREAM_POLL_WR) && (self->tx_status == kStatus_LPUART_TxIdle)) {
+        if ((flags & MP_STREAM_POLL_WR) && (self->txbuf_len > self->handle.txDataSize)) {
             ret |= MP_STREAM_POLL_WR;
         }
     } else if (request == MP_STREAM_FLUSH) {

Original file line number	Diff line number	Diff line change
`@@ -438,7 +438,7 @@ STATIC mp_uint_t machine_uart_ioctl(mp_obj_t self_in, mp_uint_t request, mp_uint`
`438`	`438`	`ret \|= MP_STREAM_POLL_RD;`
`439`	`439`	`}`
`440`	`440`	`}`
`441`		`- if ((flags & MP_STREAM_POLL_WR) && (self->tx_status == kStatus_LPUART_TxIdle)) {`
	`441`	`+ if ((flags & MP_STREAM_POLL_WR) && (self->txbuf_len > self->handle.txDataSize)) {`
`442`	`442`	`ret \|= MP_STREAM_POLL_WR;`
`443`	`443`	`}`
`444`	`444`	`} else if (request == MP_STREAM_FLUSH) {`