stm32 : move tx_enable pin cfg for uart_stream to own function (#25)

* stm32 : move tx_enable pin cfg for uart_stream to own function Also add rx_enable and pin polarity options. This is needed for RS485 where the receive enable pin must be disabled while transmitting (in half-duplex mode) and also has inverted polarity. --------- Co-authored-by: Per Knytt <[email protected]>
andoma · Dec 3, 2024 · 4a1d049 · 4a1d049
1 parent 1f68559
commit 4a1d049
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Showing 8 changed files with 42 additions and 18 deletions.
diff --git a/src/platform/stm32/stm32_uart_stream.c b/src/platform/stm32/stm32_uart_stream.c
@@ -13,7 +13,6 @@
 
 #include "stm32_uart_stream.h"
 
-
 static void
 stm32_uart_update_cr1(stm32_uart_stream_t *u)
 {
@@ -104,7 +103,10 @@ stm32_uart_write(stream_t *s, const void *buf, size_t size, int flags)
       u->tx_busy = 1;
 
       if(u->tx_enable != GPIO_UNUSED && !u->tx_enabled) {
-        gpio_set_output(u->tx_enable, 1);
+        gpio_set_output(u->tx_enable, !u->tx_pol_invert);
+        if(u->rx_enable != GPIO_UNUSED)
+          gpio_set_output(u->rx_enable, u->rx_pol_invert);
+
         u->tx_enabled = 1;
       }
 
@@ -199,14 +201,17 @@ uart_irq(void *arg)
     }
   }
 
-  if(sr & (1 << 6)) {
+  if(sr & (1 << 6)) { // Transmission complete
     if(u->tx_enable != GPIO_UNUSED) {
-      gpio_set_output(u->tx_enable, 0);
+      gpio_set_output(u->tx_enable, u->tx_pol_invert);
+      if(u->rx_enable != GPIO_UNUSED)
+        gpio_set_output(u->rx_enable, !u->rx_pol_invert);
+
       u->tx_enabled = 0;
     }
   }
 
-  if(sr & (1 << 7)) {
+  if(sr & (1 << 7)) { // TX reg empty
     uint8_t avail = u->tx_fifo_wrptr - u->tx_fifo_rdptr;
     if(avail == 0) {
       u->tx_busy = 0;
@@ -232,15 +237,24 @@ stm32_uart_print_info(struct device *dev, struct stream *st)
            u->rx_framing_error);
 }
 
+void
+stm32_uart_set_io_ctrl(stream_t *s, gpio_t tx_enable, int tx_pol_invert,
+                       gpio_t rx_enable, int rx_pol_invert)
+{
+  stm32_uart_stream_t *u = (stm32_uart_stream_t *)s;
+  u->tx_enable = tx_enable;
+  u->tx_pol_invert = !!tx_pol_invert;
+  u->rx_enable = rx_enable;
+  u->rx_pol_invert = !!rx_pol_invert;
+}
 
 static const device_class_t stm32_uart_class = {
   .dc_print_info = stm32_uart_print_info,
 };
 
 stm32_uart_stream_t *
 stm32_uart_stream_init(stm32_uart_stream_t *u, int reg_base, int baudrate,
-                       int clkid, int irq, uint8_t flags, gpio_t tx_enable,
-                       const char *name)
+                       int clkid, int irq, uint8_t flags, const char *name)
 {
   if(u == NULL)
     u = calloc(1, sizeof(stm32_uart_stream_t));
@@ -253,7 +267,6 @@ stm32_uart_stream_init(stm32_uart_stream_t *u, int reg_base, int baudrate,
 
   u->reg_base = reg_base;
   u->flags = flags;
-  u->tx_enable = tx_enable;
 
   const unsigned int freq = clk_get_freq(clkid);
   const unsigned int bbr = (freq + baudrate - 1) / baudrate;

diff --git a/src/platform/stm32/stm32_uart_stream.h b/src/platform/stm32/stm32_uart_stream.h
@@ -24,8 +24,12 @@ typedef struct stm32_uart_stream {
   uint8_t flags;
 
   gpio_t tx_enable;
+  uint8_t tx_pol_invert;
   uint8_t tx_enabled;
 
+  gpio_t rx_enable;
+  uint8_t rx_pol_invert;
+
   uint8_t rx_fifo_rdptr;
   uint8_t rx_fifo_wrptr;
   uint8_t tx_fifo_rdptr;

diff --git a/src/platform/stm32f4/stm32f4_uart.h b/src/platform/stm32f4/stm32f4_uart.h
@@ -27,13 +27,16 @@ typedef struct {
   uint32_t rxdma;
 } stm32f4_uart_config_t;
 
-stream_t *stm32f4_uart_stream_init(struct stm32_uart_stream *uart,
-                                   int instance, int baudrate,
-                                   gpio_t tx, gpio_t rx, gpio_t tx_enable,
+stream_t *stm32f4_uart_stream_init(struct stm32_uart_stream *uart, int instance,
+                                   int baudrate, gpio_t tx, gpio_t rx,
                                    uint8_t flags, const char *name);
 
 void stm32f4_uart_mbus_multidrop_create(unsigned int instance,
                                         gpio_t tx, gpio_t rx, gpio_t txe,
                                         const char *name);
 
+void stm32f4_uart_set_io_ctrl(stream_t *uart, gpio_t tx_enable,
+                              int tx_pol_invert, gpio_t rx_enable,
+                              int rx_pol_invert);
+
 const stm32f4_uart_config_t *stm32f4_uart_get_config(int index);
diff --git a/src/platform/stm32f4/stm32f4_uart_stream.c b/src/platform/stm32f4/stm32f4_uart_stream.c
@@ -24,10 +24,16 @@ stm32f4_uart_get_config(int index)
 
 static stm32_uart_stream_t *uarts[6];
 
+void
+stm32f4_uart_set_io_ctrl(stream_t *s, gpio_t tx_enable, int tx_pol_invert,
+                         gpio_t rx_enable, int rx_pol_invert)
+{
+  stm32_uart_set_io_ctrl(s, tx_enable, tx_pol_invert, rx_enable, rx_pol_invert);
+}
+
 stream_t *
 stm32f4_uart_stream_init(stm32_uart_stream_t *u, int instance, int baudrate,
-                         gpio_t tx, gpio_t rx, gpio_t tx_enable, uint8_t flags,
-                         const char *name)
+                         gpio_t tx, gpio_t rx, uint8_t flags, const char *name)
 {
   const int index = instance - 1;
   const stm32f4_uart_config_t *cfg = stm32f4_uart_get_config(index);
@@ -46,7 +52,6 @@ stm32f4_uart_stream_init(stm32_uart_stream_t *u, int instance, int baudrate,
                              cfg->clkid,
                              cfg->irq,
                              flags,
-                             tx_enable,
                              name);
 
   uarts[index] = u;

diff --git a/src/platform/stm32f405-feather/stm32f405-feather.c b/src/platform/stm32f405-feather/stm32f405-feather.c
@@ -21,7 +21,7 @@ board_init_console(void)
 {
   static stm32_uart_stream_t console;
   stdio = stm32f4_uart_stream_init(&console, 6, 115200, GPIO_PC(6), GPIO_PC(7),
-                                   GPIO_UNUSED, UART_CTRLD_IS_PANIC, "console");
+                                   UART_CTRLD_IS_PANIC, "console");
 }
 
 

diff --git a/src/platform/stm32f407g-disc1/stm32f407g-disc1.c b/src/platform/stm32f407g-disc1/stm32f407g-disc1.c
@@ -18,7 +18,7 @@ board_init_console(void)
 {
   static stm32_uart_stream_t console;
   stdio = stm32f4_uart_stream_init(&console, 2, 115200, GPIO_PA(2), GPIO_PA(3),
-                                   GPIO_UNUSED, UART_CTRLD_IS_PANIC, "console");
+                                   UART_CTRLD_IS_PANIC, "console");
 }
 
 

diff --git a/src/platform/stm32f439-nucleo144/stm32f439-nucleo144.c b/src/platform/stm32f439-nucleo144/stm32f439-nucleo144.c
@@ -23,7 +23,7 @@ board_init_console(void)
 {
   static stm32_uart_stream_t console;
   stdio = stm32f4_uart_stream_init(&console, 3, 115200, GPIO_PD(8), GPIO_PD(9),
-                                   GPIO_UNUSED, UART_CTRLD_IS_PANIC, "console");
+                                   UART_CTRLD_IS_PANIC, "console");
 }
 
 static const uint8_t stm32f439_nucleo144_ethernet_gpios[] =

diff --git a/src/platform/stm32g0/stm32g0_uart_stream.c b/src/platform/stm32g0/stm32g0_uart_stream.c
@@ -79,7 +79,6 @@ stm32g0_uart_stream_init(stm32_uart_stream_t *u, unsigned int instance,
                              cfg->clkid,
                              cfg->irq,
                              flags,
-                             GPIO_UNUSED,
                              name);
 
   uarts[instance - 1] = u;