SoC: rsnd: add interrupt support for SSI BUSIF buffer

SSI BUSIF buffer is possible to overflow or underflow, especially in a
hypervisor environment. If there is no interrupt support, it will eventually
lead to errors in pcm data.
This patch adds overflow and underflow interrupt support for SSI BUSIF buffer.
Reported-by: Chen Li <licheng0822@thundersoft.com>
Signed-off-by: Yongbo Zhang <giraffesnn123@gmail.com>
Tested-by: Chen Li <licheng0822@thundersoft.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/20200512093003.28332-1-giraffesnn123@gmail.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sh/rcar/gen.c

@@ -224,6 +224,14 @@ static int rsnd_gen2_probe(struct rsnd_priv *priv)
 		RSND_GEN_S_REG(SSI_SYS_STATUS5,	0x884),
 		RSND_GEN_S_REG(SSI_SYS_STATUS6,	0x888),
 		RSND_GEN_S_REG(SSI_SYS_STATUS7,	0x88c),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE0, 0x850),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE1, 0x854),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE2, 0x858),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE3, 0x85c),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE4, 0x890),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE5, 0x894),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE6, 0x898),
+		RSND_GEN_S_REG(SSI_SYS_INT_ENABLE7, 0x89c),
 		RSND_GEN_S_REG(HDMI0_SEL,	0x9e0),
 		RSND_GEN_S_REG(HDMI1_SEL,	0x9e4),
 

sound/soc/sh/rcar/rsnd.h

@@ -189,6 +189,14 @@ enum rsnd_reg {
 	SSI_SYS_STATUS5,
 	SSI_SYS_STATUS6,
 	SSI_SYS_STATUS7,
+	SSI_SYS_INT_ENABLE0,
+	SSI_SYS_INT_ENABLE1,
+	SSI_SYS_INT_ENABLE2,
+	SSI_SYS_INT_ENABLE3,
+	SSI_SYS_INT_ENABLE4,
+	SSI_SYS_INT_ENABLE5,
+	SSI_SYS_INT_ENABLE6,
+	SSI_SYS_INT_ENABLE7,
 	HDMI0_SEL,
 	HDMI1_SEL,
 	SSI9_BUSIF0_MODE,
@@ -237,6 +245,7 @@ enum rsnd_reg {
 #define SSI9_BUSIF_ADINR(i)	(SSI9_BUSIF0_ADINR + (i))
 #define SSI9_BUSIF_DALIGN(i)	(SSI9_BUSIF0_DALIGN + (i))
 #define SSI_SYS_STATUS(i)	(SSI_SYS_STATUS0 + (i))
+#define SSI_SYS_INT_ENABLE(i) (SSI_SYS_INT_ENABLE0 + (i))
 
 
 struct rsnd_priv;

sound/soc/sh/rcar/ssi.c

@@ -372,6 +372,9 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 	u32 wsr		= ssi->wsr;
 	int width;
 	int is_tdm, is_tdm_split;
+	int id = rsnd_mod_id(mod);
+	int i;
+	u32 sys_int_enable = 0;
 
 	is_tdm		= rsnd_runtime_is_tdm(io);
 	is_tdm_split	= rsnd_runtime_is_tdm_split(io);
@@ -447,6 +450,38 @@ static void rsnd_ssi_config_init(struct rsnd_mod *mod,
 		cr_mode = DIEN;		/* PIO : enable Data interrupt */
 	}
 
+	/* enable busif buffer over/under run interrupt. */
+	if (is_tdm || is_tdm_split) {
+		switch (id) {
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+		case 4:
+			for (i = 0; i < 4; i++) {
+				sys_int_enable = rsnd_mod_read(mod,
+					SSI_SYS_INT_ENABLE(i * 2));
+				sys_int_enable |= 0xf << (id * 4);
+				rsnd_mod_write(mod,
+					       SSI_SYS_INT_ENABLE(i * 2),
+					       sys_int_enable);
+			}
+
+			break;
+		case 9:
+			for (i = 0; i < 4; i++) {
+				sys_int_enable = rsnd_mod_read(mod,
+					SSI_SYS_INT_ENABLE((i * 2) + 1));
+				sys_int_enable |= 0xf << 4;
+				rsnd_mod_write(mod,
+					       SSI_SYS_INT_ENABLE((i * 2) + 1),
+					       sys_int_enable);
+			}
+
+			break;
+		}
+	}
+
 init_end:
 	ssi->cr_own	= cr_own;
 	ssi->cr_mode	= cr_mode;
@@ -496,6 +531,13 @@ static int rsnd_ssi_quit(struct rsnd_mod *mod,
 {
 	struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
 	struct device *dev = rsnd_priv_to_dev(priv);
+	int is_tdm, is_tdm_split;
+	int id = rsnd_mod_id(mod);
+	int i;
+	u32 sys_int_enable = 0;
+
+	is_tdm		= rsnd_runtime_is_tdm(io);
+	is_tdm_split	= rsnd_runtime_is_tdm_split(io);
 
 	if (!rsnd_ssi_is_run_mods(mod, io))
 		return 0;
@@ -517,6 +559,38 @@ static int rsnd_ssi_quit(struct rsnd_mod *mod,
 		ssi->wsr	= 0;
 	}
 
+	/* disable busif buffer over/under run interrupt. */
+	if (is_tdm || is_tdm_split) {
+		switch (id) {
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+		case 4:
+			for (i = 0; i < 4; i++) {
+				sys_int_enable = rsnd_mod_read(mod,
+						SSI_SYS_INT_ENABLE(i * 2));
+				sys_int_enable &= ~(0xf << (id * 4));
+				rsnd_mod_write(mod,
+					       SSI_SYS_INT_ENABLE(i * 2),
+					       sys_int_enable);
+			}
+
+			break;
+		case 9:
+			for (i = 0; i < 4; i++) {
+				sys_int_enable = rsnd_mod_read(mod,
+					SSI_SYS_INT_ENABLE((i * 2) + 1));
+				sys_int_enable &= ~(0xf << 4);
+				rsnd_mod_write(mod,
+					       SSI_SYS_INT_ENABLE((i * 2) + 1),
+					       sys_int_enable);
+			}
+
+			break;
+		}
+	}
+
 	return 0;
 }
 
@@ -622,6 +696,11 @@ static int rsnd_ssi_irq(struct rsnd_mod *mod,
 			int enable)
 {
 	u32 val = 0;
+	int is_tdm, is_tdm_split;
+	int id = rsnd_mod_id(mod);
+
+	is_tdm		= rsnd_runtime_is_tdm(io);
+	is_tdm_split	= rsnd_runtime_is_tdm_split(io);
 
 	if (rsnd_is_gen1(priv))
 		return 0;
@@ -635,6 +714,19 @@ static int rsnd_ssi_irq(struct rsnd_mod *mod,
 	if (enable)
 		val = rsnd_ssi_is_dma_mode(mod) ? 0x0e000000 : 0x0f000000;
 
+	if (is_tdm || is_tdm_split) {
+		switch (id) {
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+		case 4:
+		case 9:
+			val |= 0x0000ff00;
+			break;
+		}
+	}
+
 	rsnd_mod_write(mod, SSI_INT_ENABLE, val);
 
 	return 0;
@@ -651,6 +743,12 @@ static void __rsnd_ssi_interrupt(struct rsnd_mod *mod,
 	u32 status;
 	bool elapsed = false;
 	bool stop = false;
+	int id = rsnd_mod_id(mod);
+	int i;
+	int is_tdm, is_tdm_split;
+
+	is_tdm		= rsnd_runtime_is_tdm(io);
+	is_tdm_split	= rsnd_runtime_is_tdm_split(io);
 
 	spin_lock(&priv->lock);
 
@@ -672,6 +770,53 @@ static void __rsnd_ssi_interrupt(struct rsnd_mod *mod,
 		stop = true;
 	}
 
+	status = 0;
+
+	if (is_tdm || is_tdm_split) {
+		switch (id) {
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+		case 4:
+			for (i = 0; i < 4; i++) {
+				status = rsnd_mod_read(mod,
+						       SSI_SYS_STATUS(i * 2));
+				status &= 0xf << (id * 4);
+
+				if (status) {
+					rsnd_dbg_irq_status(dev,
+						"%s err status : 0x%08x\n",
+						rsnd_mod_name(mod), status);
+					rsnd_mod_write(mod,
+						       SSI_SYS_STATUS(i * 2),
+						       0xf << (id * 4));
+					stop = true;
+					break;
+				}
+			}
+			break;
+		case 9:
+			for (i = 0; i < 4; i++) {
+				status = rsnd_mod_read(mod,
+						SSI_SYS_STATUS((i * 2) + 1));
+				status &= 0xf << 4;
+
+				if (status) {
+					rsnd_dbg_irq_status(dev,
+						"%s err status : 0x%08x\n",
+						rsnd_mod_name(mod), status);
+					rsnd_mod_write(mod,
+						SSI_SYS_STATUS((i * 2) + 1),
+						0xf << 4);
+					stop = true;
+					break;
+				}
+			}
+			break;
+		}
+	}
+
 	rsnd_ssi_status_clear(mod);
 rsnd_ssi_interrupt_out:
 	spin_unlock(&priv->lock);