From de0346065b415e03efad5746ffdee99d607a0d3c Mon Sep 17 00:00:00 2001
From: Wolfram Sang <wsa@the-dreams.de>
Date: Mon, 15 Nov 2021 20:46:28 +0100
Subject: Sansa Clip+: add RDS support

Based on a patch by Amaury Pouly which was based on a patch from Ryan
Hitchman.

I mainly moved the code for polling into the tuner driver so it can be
reused by other targets. I added the CONFIG parameter for the polling
frequency (in ticks) to save energy. Also, I did some minor cleanups.

Change-Id: I95a62e7e1e42c62dbf47ecb27a3b312a42be62aa
---
 firmware/drivers/tuner/si4700.c | 55 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

(limited to 'firmware/drivers')

diff --git a/firmware/drivers/tuner/si4700.c b/firmware/drivers/tuner/si4700.c
index 88ff6c69f7..57006b4e3c 100644
--- a/firmware/drivers/tuner/si4700.c
+++ b/firmware/drivers/tuner/si4700.c
@@ -587,12 +587,67 @@ void si4700_rds_process(void)
     if (tuner_powered())
     {
         si4700_read_reg(RDSD);
+#if (CONFIG_RDS & RDS_CFG_POLL)
+	/* we need to keep track of the ready bit because it stays set for 80ms
+	 * and we must avoid processing it twice */
+
+        static bool old_rdsr = false;
+        bool rdsr = (cache[STATUSRSSI] & STATUSRSSI_RDSR);
+        if (rdsr && !old_rdsr)
+            rds_process(&cache[RDSA]);
+        old_rdsr = rdsr;
+#else
         rds_process(&cache[RDSA]);
+#endif /* !(CONFIG_RDS & RDS_CFG_POLL) */
     }
 
     mutex_unlock(&fmr_mutex);
 }
 #endif /* (CONFIG_RDS & RDS_CFG_ISR) */
 
+#if (CONFIG_RDS & RDS_CFG_POLL)
+static struct event_queue rds_queue;
+static uint32_t rds_stack[DEFAULT_STACK_SIZE / sizeof(uint32_t)];
+
+enum {
+    Q_POWERUP,
+};
+
+static void NORETURN_ATTR rds_thread(void)
+{
+    /* start up frozen */
+    int timeout = TIMEOUT_BLOCK;
+    struct queue_event ev;
+
+    while (true) {
+        queue_wait_w_tmo(&rds_queue, &ev, timeout);
+        switch (ev.id) {
+            case Q_POWERUP:
+                /* power up: timeout after 1 tick, else block indefinitely */
+                timeout = ev.data ? CONFIG_RDS_POLL_TICKS : TIMEOUT_BLOCK;
+                break;
+            case SYS_TIMEOUT:;
+                /* Captures RDS data and processes it */
+                si4700_rds_process();
+                break;
+        }
+    }
+}
+
+/* true after full radio power up, and false before powering down */
+void si4700_rds_powerup(bool on)
+{
+    queue_post(&rds_queue, Q_POWERUP, on);
+}
+
+/* One-time RDS init at startup */
+void si4700_rds_init(void)
+{
+    queue_init(&rds_queue, false);
+    create_thread(rds_thread, rds_stack, sizeof(rds_stack), 0, "rds"
+        IF_PRIO(, PRIORITY_PLAYBACK) IF_COP(, CPU));
+}
+#endif /* !(CONFIG_RDS & RDS_CFG_POLL) */
+
 #endif /* HAVE_RDS_CAP */
 
-- 
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