Changeset e6a356dd in mainline for kernel/genarch/src/drivers/amdm37x_uart/amdm37x_uart.c

Timestamp:

2012-03-04T20:37:27Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

05a6548

Parents:

b0e58c7

Message:

amdm37x: Simple UART driver implementation (only output).

File:

• kernel/genarch/src/drivers/amdm37x_uart/amdm37x_uart.c (modified) (1 diff)

kernel/genarch/src/drivers/amdm37x_uart/amdm37x_uart.c

@@ -35 +35 @@
 
 #include <genarch/drivers/amdm37x_uart/amdm37x_uart.h>
+#include <str.h>
+#include <mm/km.h>
 
-int amdm37x_uart_init(
+static void amdm37x_uart_txb(amdm37x_uart_t *uart, uint8_t b)
+{
+        /* Wait for buffer */
+        while (uart->regs->ssr & AMDM37x_UART_SSR_TX_FIFO_FULL_FLAG);
+        /* Write to the outgoing fifo */
+        uart->regs->thr = b;
+}
+
+static void amdm37x_uart_putchar(outdev_t *dev, wchar_t ch)
+{
+        amdm37x_uart_t *uart = dev->data;
+        if (!ascii_check(ch)) {
+                amdm37x_uart_txb(uart, U_SPECIAL);
+        } else {
+                if (ch == '\n')
+                        amdm37x_uart_txb(uart, '\r');
+                amdm37x_uart_txb(uart, ch);
+        }
+}
+
+static outdev_operations_t amdm37x_uart_ops = {
+        .redraw = NULL,
+        .write = amdm37x_uart_putchar,
+};
+
+bool amdm37x_uart_init(
     amdm37x_uart_t *uart, inr_t interrupt, uintptr_t addr, size_t size)
 {
-        return 0;
+        ASSERT(uart);
+        uart->regs = (void *)km_map(addr, size, PAGE_NOT_CACHEABLE);
+
+        /* See TI OMAP35X TRM ch 17.5.1.1 p. 2732 for startup routine */
+
+        /* Soft reset the port */
+        uart->regs->sysc = AMDM37x_UART_SYSC_SOFTRESET_FLAG;
+        while (uart->regs->syss & AMDM37x_UART_SYSS_RESETDONE_FLAG) ;
+
+        /* Enable access to EFR register */
+        const uint8_t lcr = uart->regs->lcr; /* Save old value */
+        uart->regs->lcr = 0xbf;              /* Sets config mode B */
+
+        /* Enable access to TCL_TLR register */
+        const bool enhanced = uart->regs->efr & AMDM37x_UART_EFR_ENH_FLAG;
+        uart->regs->efr |= AMDM37x_UART_EFR_ENH_FLAG; /* Turn on enh. */
+        uart->regs->lcr = 0x80;              /* Config mode A */
+
+        /* Set default (val 0) triggers, disable DMA enable FIFOs */
+        const bool tcl_tlr = uart->regs->mcr & AMDM37x_UART_MCR_TCR_TLR_FLAG;
+        uart->regs->fcr = AMDM37x_UART_FCR_FIFO_EN_FLAG;
+
+        /* Enable fine granularity for rx trigger */
+        uart->regs->lcr = 0xbf;              /* Sets config mode B */
+        uart->regs->scr = AMDM37x_UART_SCR_RX_TRIG_GRANU1_FLAG;
+
+        /* Restore enhanced */
+        if (!enhanced)
+                uart->regs->efr &= ~AMDM37x_UART_EFR_ENH_FLAG;
+
+        uart->regs->lcr = 0x80;              /* Config mode A */
+        /* Restore tcl_lcr */
+        if (!tcl_tlr)
+                uart->regs->mcr &= ~AMDM37x_UART_MCR_TCR_TLR_FLAG;
+
+        /* Restore tcl_lcr */
+        uart->regs->lcr = lcr;
+
+        /* Disable interrupts */
+        uart->regs->ier = 0;
+
+        /* Setup outdev */
+        outdev_initialize("amdm37x_uart_dev", &uart->outdev, &amdm37x_uart_ops);
+        uart->outdev.data = uart;
+        return false;
 }
 
 void amdm37x_uart_input_wire(amdm37x_uart_t *uart, indev_t *indev)
 {
+        // TODO implement
+        // register interrupt
+        // set rx fifo
+        // set rx fifo threshold to 1
 }