add unfinished UART driver

1 files changed, 88 insertions, 0 deletions

diff --git a/src/cc32/uart_sc16is740.c b/src/cc32/uart_sc16is740.c
new file mode 100644
index 0000000..12fee26
--- /dev/null
+++ b/src/cc32/uart_sc16is740.c
@@ -0,0 +1,88 @@
+/*
+ * NXP SC16IS740 SPI UART driver
+ *
+ * Copyright (C) 2012 Harald Welte <laforge@gnumonks.org>
+ *
+ * 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 the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define RHR	0x00
+#define THR	0x00
+#define	IER	0x01
+#define FCR	0x02
+#define IIR	0x02
+#define LCR	0x03
+#define MCR	0x04
+#define LSR	0x05
+#define MSR	0x06
+#define SPR	0x07
+
+static void reg_write(uint8_t reg, uint8_t val)
+{
+	uint8_t cmd = (reg << 3);
+
+	cc32_spi_xcv_byte(cmd);
+	cc32_spi_xcv_byte(val);
+}
+
+static int reg_read(uint8_t reg)
+{
+	uint8_t tx = (reg << 3) | 0x80;
+
+	cc32_spi_xcv_byte(tx);
+
+	return cc32_spi_xcv_byte(0);
+}
+
+static void fifo_write(uint8_t *buf, uint8_t len)
+{
+	uint8_t cmd = (0 << 3);
+
+	cc32_spi_xcv_byte(cmd);
+
+	while (len--)
+		cc32_spi_xcv_byte(buf++);
+}
+
+static void fifo_read(uint8_t *buf, uint8_t len)
+{
+	uint8_t cmd = (reg << 3) | 0x80;
+
+	cc32_spi_xcv_byte(cmd);
+
+	while (len--)
+		*(buf++) = cc32_spi_xcv_byte(0);
+}
+
+
+void uart_sc16is740_init()
+{
+	/* set 8N1 */
+	reg_write(LCR, (3 << 0) | (0 << 2);
+	/* set LCR[7] = 1 (divisor latch) */
+	reg_write(LCR, reg_read(LCR) |= 0x80);
+	/* baud rate generator for 115200 */
+	reg_write(DLL, 1);
+	reg_write(DLH, 0);
+	/* clear LCR[7] = 0 (divisor latch) */
+	reg_write(LCR, reg_read(LCR) &= ~0x80);
+}
+
+void uart_sc16is740_putchar(uint8_t ch)
+{
+	/* wait until THR empty */
+	while (!(reg_read(LSR) & (1 << 5))) { }
+
+	reg_write(THR, ch);
+}