1 files changed, 249 insertions, 0 deletions

diff --git a/firmware/target/arm/s5l8702/ipod6g/serial-6g.c b/firmware/target/arm/s5l8702/ipod6g/serial-6g.c
new file mode 100644
index 0000000000..f1f06987bc
--- /dev/null
+++ b/firmware/target/arm/s5l8702/ipod6g/serial-6g.c
@@ -0,0 +1,249 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2014 by Cástor Muñoz
+ *
+ * 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
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "config.h"
+#include "cpu.h"
+#include "system.h"
+#include "serial.h"
+
+#include "s5l8702.h"
+#include "uc870x.h"
+
+/* Define LOGF_ENABLE to enable logf output in this file */
+#define LOGF_ENABLE
+#include "logf.h"
+
+
+/* shall include serial HW configuracion for specific target */
+#define IPOD6G_UART_CLK_HZ      12000000  /* external OSC0 ??? */
+
+/* This values below are valid with a UCLK of 12MHz */
+#define BRDATA_9600         (77)                    /* 9615   */
+#define BRDATA_19200        (38)                    /* 19231  */
+#define BRDATA_28800        (25)                    /* 28846  */
+#define BRDATA_38400        (19 | (0xc330c << 8))   /* 38305  */
+#define BRDATA_57600        (12)                    /* 57692  */
+#define BRDATA_115200       (6 | (0xffffff << 8))   /* 114286 */
+
+
+extern const struct uartc s5l8702_uartc;
+#ifdef IPOD_ACCESSORY_PROTOCOL
+static void iap_rx_isr(int, char*, char*, uint32_t);
+#endif
+
+struct uartc_port ser_port IDATA_ATTR =
+{
+    /* location */
+    .uartc = &s5l8702_uartc,
+    .id = 0,
+
+    /* configuration */
+    .rx_trg = UFCON_RX_FIFO_TRG_4,
+    .tx_trg = UFCON_TX_FIFO_TRG_EMPTY,
+    .clksel = UCON_CLKSEL_ECLK,
+    .clkhz = IPOD6G_UART_CLK_HZ,
+
+    /* interrupt callbacks */
+#ifdef IPOD_ACCESSORY_PROTOCOL
+    .rx_cb = iap_rx_isr,
+#else
+    .rx_cb = NULL,
+#endif
+    .tx_cb = NULL,  /* polling */
+};
+
+/*
+ * serial driver API
+ */
+int tx_rdy(void)
+{
+    return uartc_port_tx_ready(&ser_port) ? 1 : 0;
+}
+
+void tx_writec(unsigned char c)
+{
+    uartc_port_tx_byte(&ser_port, c);
+}
+
+#ifndef IPOD_ACCESSORY_PROTOCOL
+void serial_setup(void)
+{
+    uartc_port_open(&ser_port);
+
+    /* set a default configuration, Tx and Rx modes are
+       disabled when the port is initialized */
+    uartc_port_config(&ser_port, ULCON_DATA_BITS_8,
+                        ULCON_PARITY_NONE, ULCON_STOP_BITS_1);
+    uartc_port_set_bitrate_raw(&ser_port, BRDATA_115200);
+
+    /* enable Tx interrupt request or POLLING mode */
+    uartc_port_set_tx_mode(&ser_port, UCON_MODE_INTREQ);
+
+    logf("[%lu] "MODEL_NAME" port %d ready!", USEC_TIMER, ser_port.id);
+}
+
+
+#else /* IPOD_ACCESSORY_PROTOCOL */
+#include "kernel.h"
+#include "pmu-target.h"
+#include "iap.h"
+
+static enum {
+    ABR_STATUS_LAUNCHED,    /* ST_SYNC */
+    ABR_STATUS_SYNCING,     /* ST_SOF */
+    ABR_STATUS_DONE
+} abr_status;
+
+static int bitrate = 0;
+static bool acc_plugged = false;
+
+static void serial_acc_tick(void)
+{
+    bool plugged = pmu_accessory_present();
+    if (acc_plugged != plugged)
+    {
+        acc_plugged = plugged;
+        if (acc_plugged)
+        {
+            uartc_open(ser_port.uartc);
+            uartc_port_open(&ser_port);
+            /* set a default configuration, Tx and Rx modes are
+               disabled when the port is initialized */
+            uartc_port_config(&ser_port, ULCON_DATA_BITS_8,
+                                ULCON_PARITY_NONE, ULCON_STOP_BITS_1);
+            uartc_port_set_tx_mode(&ser_port, UCON_MODE_INTREQ);
+            serial_bitrate(bitrate);
+        }
+        else
+        {
+            uartc_port_close(&ser_port);
+            uartc_close(ser_port.uartc);
+        }
+    }
+}
+
+void serial_setup(void)
+{
+    uartc_close(ser_port.uartc);
+    tick_add_task(serial_acc_tick);
+}
+
+void serial_bitrate(int rate)
+{
+    bitrate = rate;
+    if (!acc_plugged)
+        return;
+
+    logf("[%lu] serial_bitrate(%d)", USEC_TIMER, rate);
+
+    if (rate == 0) {
+        /* Using auto-bitrate (ABR) to detect accessory Tx speed:
+         *
+         * + Here:
+         *   - Disable Rx logic to clean the FIFO and the shift
+         *     register, thus no Rx data interrupts are generated.
+         *   - Launch ABR and wait for a low pulse in Rx line.
+         *
+         * + In ISR, when a low pulse is detected (ideally it is the
+         *   start bit of 0xff):
+         *   - Calculate and configure detected speed.
+         *   - Enable Rx to verify that the next received data frame
+         *     is 0x55 or 0xff:
+         *     - If so, it's assumed bit rate is correctly detected,
+         *       it will not be modified until speed is changed using
+         *       RB options menu.
+         *     - If not, reset iAP state machine and launch a new ABR.
+         */
+        uartc_port_set_rx_mode(&ser_port, UCON_MODE_DISABLED);
+        uartc_port_abr_start(&ser_port);
+        abr_status = ABR_STATUS_LAUNCHED;
+    }
+    else {
+        uint32_t brdata;
+        if      (rate == 57600) brdata = BRDATA_57600;
+        else if (rate == 38400) brdata = BRDATA_38400;
+        else if (rate == 19200) brdata = BRDATA_19200;
+        else brdata = BRDATA_9600;
+        uartc_port_abr_stop(&ser_port); /* abort ABR if already launched */
+        uartc_port_set_bitrate_raw(&ser_port, brdata);
+        uartc_port_set_rx_mode(&ser_port, UCON_MODE_INTREQ);
+        abr_status = ABR_STATUS_DONE;
+    }
+}
+
+static void iap_rx_isr(int len, char *data, char *err, uint32_t abr_cnt)
+{
+    /* ignore Rx errors, upper layer will discard bad packets */
+    (void) err;
+
+    static int sync_retry;
+
+    if (abr_status == ABR_STATUS_LAUNCHED) {
+        /* autobauding */
+        if (abr_cnt) {
+            #define BR2CNT(s) (IPOD6G_UART_CLK_HZ / (unsigned)(s))
+            if (abr_cnt < BR2CNT(57600*1.1) || abr_cnt > BR2CNT(9600*0.9)) {
+                /* detected speed out of range, relaunch ABR */
+                uartc_port_abr_start(&ser_port);
+                return;
+            }
+            /* valid speed detected, select it */
+            uint32_t brdata;
+            if      (abr_cnt < BR2CNT(48000)) brdata = BRDATA_57600;
+            else if (abr_cnt < BR2CNT(33600)) brdata = BRDATA_38400;
+            else if (abr_cnt < BR2CNT(24000)) brdata = BRDATA_28800;
+            else if (abr_cnt < BR2CNT(14400)) brdata = BRDATA_19200;
+            else brdata = BRDATA_9600;
+
+            /* set detected speed */
+            uartc_port_set_bitrate_raw(&ser_port, brdata);
+            uartc_port_set_rx_mode(&ser_port, UCON_MODE_INTREQ);
+
+            /* enter SOF state */
+            iap_getc(0xff);
+
+            abr_status = ABR_STATUS_SYNCING;
+            sync_retry = 2; /* we are expecting [0xff] 0x55 */
+        }
+    }
+
+    /* process received data */
+    while (len--)
+    {
+        bool sync_done = !iap_getc(*data++);
+
+        if (abr_status == ABR_STATUS_SYNCING)
+        {
+            if (sync_done) {
+                abr_status = ABR_STATUS_DONE;
+            }
+            else if (--sync_retry == 0) {
+                /* invalid speed detected, relaunch ABR
+                   discarding remaining data (if any) */
+                serial_bitrate(0);
+                break;
+            }
+        }
+    }
+}
+#endif /* IPOD_ACCESSORY_PROTOCOL */