[PATCH 4/5] ASoC: wm_adsp: Signal firmware shutdown through event control

[Richard Fitzgerald <rf@opensource.wolfsonmicro.com>]

If the firmware has any system event signalling controls, signal
them during DSP PRE_PMD to tell the firmware it is about to be stopped.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
---
 sound/soc/codecs/wm_adsp.c | 114 +++++++++++++++++++++++++++++++++++++++++++++
 sound/soc/codecs/wmfw.h    |   3 ++
 2 files changed, 117 insertions(+)

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index 82bb3dc..bdbcc44 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -162,6 +162,14 @@
 
 #define ADSP_MAX_STD_CTRL_SIZE               512
 
+#define WM_ADSP_ACKED_CTL_TIMEOUT_MS         100
+#define WM_ADSP_ACKED_CTL_N_QUICKPOLLS       10
+
+/*
+ * Event control messages
+ */
+#define WM_ADSP_FW_EVENT_SHUTDOWN            0x000001
+
 struct wm_adsp_buf {
 	struct list_head list;
 	void *buf;
@@ -776,6 +784,66 @@ static int wm_coeff_info(struct snd_kcontrol *kctl,
 	return 0;
 }
 
+static int wm_coeff_write_acked_control(struct wm_coeff_ctl *ctl,
+					unsigned int event_id)
+{
+	struct wm_adsp *dsp = ctl->dsp;
+	u32 val = cpu_to_be32(event_id);
+	unsigned int reg;
+	int i, ret;
+
+	ret = wm_coeff_base_reg(ctl, &reg);
+	if (ret)
+		return ret;
+
+	adsp_dbg(dsp, "Sending 0x%x to acked control alg 0x%x %s:0x%x\n",
+		 event_id, ctl->alg_region.alg,
+		 wm_adsp_mem_region_name(ctl->alg_region.type), ctl->offset);
+
+	ret = regmap_raw_write(dsp->regmap, reg, &val, sizeof(val));
+	if (ret) {
+		adsp_err(dsp, "Failed to write %x: %d\n", reg, ret);
+		return ret;
+	}
+
+	/*
+	 * Poll for ack, we initially poll at ~1ms intervals for firmwares
+	 * that respond quickly, then go to ~10ms polls. A firmware is unlikely
+	 * to ack instantly so we do the first 1ms delay before reading the
+	 * control to avoid a pointless bus transaction
+	 */
+	for (i = 0; i < WM_ADSP_ACKED_CTL_TIMEOUT_MS;) {
+		switch (i) {
+		case 0 ... WM_ADSP_ACKED_CTL_N_QUICKPOLLS - 1:
+			usleep_range(1000, 2000);
+			i++;
+			break;
+		default:
+			usleep_range(10000, 20000);
+			i += 10;
+			break;
+		}
+
+		ret = regmap_raw_read(dsp->regmap, reg, &val, sizeof(val));
+		if (ret) {
+			adsp_err(dsp, "Failed to read %x: %d\n", reg, ret);
+			return ret;
+		}
+
+		if (val == 0) {
+			adsp_dbg(dsp, "Acked control ACKED at poll %u\n", i);
+			return 0;
+		}
+	}
+
+	adsp_warn(dsp, "Acked control @0x%x alg:0x%x %s:0x%x timed out\n",
+		  reg, ctl->alg_region.alg,
+		  wm_adsp_mem_region_name(ctl->alg_region.type),
+		  ctl->offset);
+
+	return -ETIMEDOUT;
+}
+
 static int wm_coeff_write_control(struct wm_coeff_ctl *ctl,
 				  const void *buf, size_t len)
 {
@@ -1055,6 +1123,24 @@ static int wm_coeff_sync_controls(struct wm_adsp *dsp)
 	return 0;
 }
 
+static void wm_adsp_signal_event_controls(struct wm_adsp *dsp,
+					  unsigned int event)
+{
+	struct wm_coeff_ctl *ctl;
+	int ret;
+
+	list_for_each_entry(ctl, &dsp->ctl_list, list) {
+		if (ctl->type != WMFW_CTL_TYPE_HOSTEVENT)
+			continue;
+
+		ret = wm_coeff_write_acked_control(ctl, event);
+		if (ret)
+			adsp_warn(dsp,
+				  "Failed to send 0x%x event to alg 0x%x (%d)\n",
+				  event, ctl->alg_region.alg, ret);
+	}
+}
+
 static void wm_adsp_ctl_work(struct work_struct *work)
 {
 	struct wmfw_ctl_work *ctl_work = container_of(work,
@@ -1314,6 +1400,21 @@ static inline void wm_coeff_parse_coeff(struct wm_adsp *dsp, const u8 **data,
 	adsp_dbg(dsp, "\tALSA control len: %#x\n", blk->len);
 }
 
+static int wm_adsp_check_coeff_flags(struct wm_adsp *dsp,
+				const struct wm_coeff_parsed_coeff *coeff_blk,
+				unsigned int f_required,
+				unsigned int f_illegal)
+{
+	if ((coeff_blk->flags & f_illegal) ||
+	    ((coeff_blk->flags & f_required) != f_required)) {
+		adsp_err(dsp, "Illegal flags 0x%x for control type 0x%x\n",
+			 coeff_blk->flags, coeff_blk->ctl_type);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static int wm_adsp_parse_coeff(struct wm_adsp *dsp,
 			       const struct wmfw_region *region)
 {
@@ -1330,6 +1431,16 @@ static int wm_adsp_parse_coeff(struct wm_adsp *dsp,
 		switch (coeff_blk.ctl_type) {
 		case SNDRV_CTL_ELEM_TYPE_BYTES:
 			break;
+		case WMFW_CTL_TYPE_HOSTEVENT:
+			ret = wm_adsp_check_coeff_flags(dsp, &coeff_blk,
+						WMFW_CTL_FLAG_SYS |
+						WMFW_CTL_FLAG_VOLATILE |
+						WMFW_CTL_FLAG_WRITEABLE |
+						WMFW_CTL_FLAG_READABLE,
+						0);
+			if (ret)
+				return -EINVAL;
+			break;
 		default:
 			adsp_err(dsp, "Unknown control type: %d\n",
 				 coeff_blk.ctl_type);
@@ -2401,6 +2512,9 @@ int wm_adsp2_event(struct snd_soc_dapm_widget *w,
 		break;
 
 	case SND_SOC_DAPM_PRE_PMD:
+		/* Tell the firmware to cleanup */
+		wm_adsp_signal_event_controls(dsp, WM_ADSP_FW_EVENT_SHUTDOWN);
+
 		/* Log firmware state, it can be useful for analysis */
 		wm_adsp2_show_fw_status(dsp);
 
diff --git a/sound/soc/codecs/wmfw.h b/sound/soc/codecs/wmfw.h
index 7613d60..892fc74 100644
--- a/sound/soc/codecs/wmfw.h
+++ b/sound/soc/codecs/wmfw.h
@@ -26,6 +26,9 @@
 #define WMFW_CTL_FLAG_WRITEABLE   0x0002
 #define WMFW_CTL_FLAG_READABLE    0x0001
 
+/* Non-ALSA coefficient types start at 0x1000 */
+#define WMFW_CTL_TYPE_HOSTEVENT   0x1001 /* event control */
+
 struct wmfw_header {
 	char magic[4];
 	__le32 len;
-- 
1.9.1