--- /dev/null
+/*
+ * (C) Copyright 2003
+ *
+ * Pantelis Antoniou <panto@intracom.gr>
+ * Intracom S.A.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <watchdog.h>
+#include <serial.h>
+#include <linux/compiler.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**************************************************************/
+
+/* convienient macros */
+#define MAX3100_SPI_RXD() (MAX3100_SPI_RXD_PORT & MAX3100_SPI_RXD_BIT)
+
+#define MAX3100_SPI_TXD(x) \
+ do { \
+ if (x) \
+ MAX3100_SPI_TXD_PORT |= MAX3100_SPI_TXD_BIT; \
+ else \
+ MAX3100_SPI_TXD_PORT &= ~MAX3100_SPI_TXD_BIT; \
+ } while(0)
+
+#define MAX3100_SPI_CLK(x) \
+ do { \
+ if (x) \
+ MAX3100_SPI_CLK_PORT |= MAX3100_SPI_CLK_BIT; \
+ else \
+ MAX3100_SPI_CLK_PORT &= ~MAX3100_SPI_CLK_BIT; \
+ } while(0)
+
+#define MAX3100_SPI_CLK_TOGGLE() (MAX3100_SPI_CLK_PORT ^= MAX3100_SPI_CLK_BIT)
+
+#define MAX3100_CS(x) \
+ do { \
+ if (x) \
+ MAX3100_CS_PORT |= MAX3100_CS_BIT; \
+ else \
+ MAX3100_CS_PORT &= ~MAX3100_CS_BIT; \
+ } while(0)
+
+/**************************************************************/
+
+/* MAX3100 definitions */
+
+#define MAX3100_WC (3 << 14) /* write configuration */
+#define MAX3100_RC (1 << 14) /* read configuration */
+#define MAX3100_WD (2 << 14) /* write data */
+#define MAX3100_RD (0 << 14) /* read data */
+
+/* configuration register bits */
+#define MAX3100_FEN (1 << 13) /* FIFO enable */
+#define MAX3100_SHDN (1 << 12) /* shutdown bit */
+#define MAX3100_TM (1 << 11) /* T bit irq mask */
+#define MAX3100_RM (1 << 10) /* R bit irq mask */
+#define MAX3100_PM (1 << 9) /* P bit irq mask */
+#define MAX3100_RAM (1 << 8) /* mask for RA/FE bit */
+#define MAX3100_IR (1 << 7) /* IRDA timing mode */
+#define MAX3100_ST (1 << 6) /* transmit stop bit */
+#define MAX3100_PE (1 << 5) /* parity enable bit */
+#define MAX3100_L (1 << 4) /* Length bit */
+#define MAX3100_B_MASK (0x000F) /* baud rate bits mask */
+#define MAX3100_B(x) ((x) & 0x000F) /* baud rate select bits */
+
+/* data register bits (write) */
+#define MAX3100_TE (1 << 10) /* transmit enable bit (active low) */
+#define MAX3100_RTS (1 << 9) /* request-to-send bit (inverted ~RTS pin) */
+
+/* data register bits (read) */
+#define MAX3100_RA (1 << 10) /* receiver activity when in shutdown mode */
+#define MAX3100_FE (1 << 10) /* framing error when in normal mode */
+#define MAX3100_CTS (1 << 9) /* clear-to-send bit (inverted ~CTS pin) */
+
+/* data register bits (both directions) */
+#define MAX3100_R (1 << 15) /* receive bit */
+#define MAX3100_T (1 << 14) /* transmit bit */
+#define MAX3100_P (1 << 8) /* parity bit */
+#define MAX3100_D_MASK 0x00FF /* data bits mask */
+#define MAX3100_D(x) ((x) & 0x00FF) /* data bits */
+
+/* these definitions are valid only for fOSC = 3.6864MHz */
+#define MAX3100_B_230400 MAX3100_B(0)
+#define MAX3100_B_115200 MAX3100_B(1)
+#define MAX3100_B_57600 MAX3100_B(2)
+#define MAX3100_B_38400 MAX3100_B(9)
+#define MAX3100_B_19200 MAX3100_B(10)
+#define MAX3100_B_9600 MAX3100_B(11)
+#define MAX3100_B_4800 MAX3100_B(12)
+#define MAX3100_B_2400 MAX3100_B(13)
+#define MAX3100_B_1200 MAX3100_B(14)
+#define MAX3100_B_600 MAX3100_B(15)
+
+/**************************************************************/
+
+static inline unsigned int max3100_transfer(unsigned int val)
+{
+ unsigned int rx;
+ int b;
+
+ MAX3100_SPI_CLK(0);
+ MAX3100_CS(0);
+
+ rx = 0; b = 16;
+ while (--b >= 0) {
+ MAX3100_SPI_TXD(val & 0x8000);
+ val <<= 1;
+ MAX3100_SPI_CLK_TOGGLE();
+ udelay(1);
+ rx <<= 1;
+ if (MAX3100_SPI_RXD())
+ rx |= 1;
+ MAX3100_SPI_CLK_TOGGLE();
+ udelay(1);
+ }
+
+ MAX3100_SPI_CLK(1);
+ MAX3100_CS(1);
+
+ return rx;
+}
+
+/**************************************************************/
+
+/* must be power of 2 */
+#define RXFIFO_SZ 16
+
+static int rxfifo_cnt;
+static int rxfifo_in;
+static int rxfifo_out;
+static unsigned char rxfifo_buf[16];
+
+static void max3100_serial_putc_raw(int c)
+{
+ unsigned int rx;
+
+ while (((rx = max3100_transfer(MAX3100_RC)) & MAX3100_T) == 0)
+ WATCHDOG_RESET();
+
+ rx = max3100_transfer(MAX3100_WD | (c & 0xff));
+ if ((rx & MAX3100_RD) != 0 && rxfifo_cnt < RXFIFO_SZ) {
+ rxfifo_cnt++;
+ rxfifo_buf[rxfifo_in++] = rx & 0xff;
+ rxfifo_in &= RXFIFO_SZ - 1;
+ }
+}
+
+static int max3100_serial_getc(void)
+{
+ int c;
+ unsigned int rx;
+
+ while (rxfifo_cnt == 0) {
+ rx = max3100_transfer(MAX3100_RD);
+ if ((rx & MAX3100_R) != 0) {
+ do {
+ rxfifo_cnt++;
+ rxfifo_buf[rxfifo_in++] = rx & 0xff;
+ rxfifo_in &= RXFIFO_SZ - 1;
+
+ if (rxfifo_cnt >= RXFIFO_SZ)
+ break;
+ } while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
+ }
+ WATCHDOG_RESET();
+ }
+
+ rxfifo_cnt--;
+ c = rxfifo_buf[rxfifo_out++];
+ rxfifo_out &= RXFIFO_SZ - 1;
+ return c;
+}
+
+static int max3100_serial_tstc(void)
+{
+ unsigned int rx;
+
+ if (rxfifo_cnt > 0)
+ return 1;
+
+ rx = max3100_transfer(MAX3100_RD);
+ if ((rx & MAX3100_R) == 0)
+ return 0;
+
+ do {
+ rxfifo_cnt++;
+ rxfifo_buf[rxfifo_in++] = rx & 0xff;
+ rxfifo_in &= RXFIFO_SZ - 1;
+
+ if (rxfifo_cnt >= RXFIFO_SZ)
+ break;
+ } while (((rx = max3100_transfer(MAX3100_RD)) & MAX3100_R) != 0);
+
+ return 1;
+}
+
+static int max3100_serial_init(void)
+{
+ unsigned int wconf, rconf;
+ int i;
+
+ wconf = 0;
+
+ /* Set baud rate */
+ switch (gd->baudrate) {
+ case 1200:
+ wconf = MAX3100_B_1200;
+ break;
+ case 2400:
+ wconf = MAX3100_B_2400;
+ break;
+ case 4800:
+ wconf = MAX3100_B_4800;
+ break;
+ case 9600:
+ wconf = MAX3100_B_9600;
+ break;
+ case 19200:
+ wconf = MAX3100_B_19200;
+ break;
+ case 38400:
+ wconf = MAX3100_B_38400;
+ break;
+ case 57600:
+ wconf = MAX3100_B_57600;
+ break;
+ default:
+ case 115200:
+ wconf = MAX3100_B_115200;
+ break;
+ case 230400:
+ wconf = MAX3100_B_230400;
+ break;
+ }
+
+ /* try for 10ms, with a 100us gap */
+ for (i = 0; i < 10000; i += 100) {
+
+ max3100_transfer(MAX3100_WC | wconf);
+ rconf = max3100_transfer(MAX3100_RC) & 0x3fff;
+
+ if (rconf == wconf)
+ break;
+ udelay(100);
+ }
+
+ rxfifo_in = rxfifo_out = rxfifo_cnt = 0;
+
+ return (0);
+}
+
+static void max3100_serial_putc(const char c)
+{
+ if (c == '\n')
+ max3100_serial_putc_raw('\r');
+
+ max3100_serial_putc_raw(c);
+}
+
+static void max3100_serial_puts(const char *s)
+{
+ while (*s)
+ max3100_serial_putc_raw(*s++);
+}
+
+static void max3100_serial_setbrg(void)
+{
+}
+
+static struct serial_device max3100_serial_drv = {
+ .name = "max3100_serial",
+ .start = max3100_serial_init,
+ .stop = NULL,
+ .setbrg = max3100_serial_setbrg,
+ .putc = max3100_serial_putc,
+ .puts = max3100_serial_puts,
+ .getc = max3100_serial_getc,
+ .tstc = max3100_serial_tstc,
+};
+
+void max3100_serial_initialize(void)
+{
+ serial_register(&max3100_serial_drv);
+}
+
+__weak struct serial_device *default_serial_console(void)
+{
+ return &max3100_serial_drv;
+}
Code Review / kvmfornfv.git / blobdiff