[PATCH v2] remoteproc: mediatek: fix side effect of mt8195 sram power on

Tinghan Shen
2022-03-11T12:31:16Z

The definition of L1TCM_SRAM_PDN bits on mt8195 is different to mt8192.

L1TCM_SRAM_PDN bits[3:0] control the power of mt8195 L1TCM SRAM.

L1TCM_SRAM_PDN bits[7:4] control the access path to EMI for SCP.
These bits have to be powered on to allow EMI access for SCP.

Bits[7:4] also affect audio DSP because audio DSP and SCP are
placed on the same hardware bus. If SCP cannot access EMI, audio DSP is
blocked too.

L1TCM_SRAM_PDN bits[31:8] are not used.

This fix removes modification of bits[7:4] when power on/off mt8195 SCP
L1TCM. It's because the modification introduces a short period of time
blocking audio DSP to access EMI. This was not a problem until we have
to load both SCP module and audio DSP module. audio DSP needs to access
EMI because it has source/data on DRAM. Audio DSP will have unexpected
behavior when it accesses EMI and the SCP driver blocks the EMI path at
the same time.

Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
---
drivers/remoteproc/mtk_common.h | 2 +
drivers/remoteproc/mtk_scp.c | 67 +++++++++++++++++++++++++--------
2 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/drivers/remoteproc/mtk_common.h b/drivers/remoteproc/mtk_common.h
index 5ff3867c72f3..ff954a06637c 100644
--- a/drivers/remoteproc/mtk_common.h
+++ b/drivers/remoteproc/mtk_common.h
@@ -51,6 +51,8 @@
#define MT8192_CORE0_WDT_IRQ 0x10030
#define MT8192_CORE0_WDT_CFG 0x10034

+#define MT8195_L1TCM_SRAM_PDN_RESERVED_RSI_BITS GENMASK(7, 4)
+
#define SCP_FW_VER_LEN 32
#define SCP_SHARE_BUFFER_SIZE 288

diff --git a/drivers/remoteproc/mtk_scp.c b/drivers/remoteproc/mtk_scp.c
index dcddb33e9997..086cf8263f6c 100644
--- a/drivers/remoteproc/mtk_scp.c
+++ b/drivers/remoteproc/mtk_scp.c
@@ -365,22 +365,22 @@ static int mt8183_scp_before_load(struct mtk_scp *scp)
return 0;
}

-static void mt8192_power_on_sram(void __iomem *addr)
+static void scp_sram_power_on(void __iomem *addr, u32 reserved_mask)
{
int i;

for (i = 31; i >= 0; i--)
- writel(GENMASK(i, 0), addr);
+ writel(GENMASK(i, 0) & ~reserved_mask, addr);
writel(0, addr);
}

-static void mt8192_power_off_sram(void __iomem *addr)
+static void scp_sram_power_off(void __iomem *addr, u32 reserved_mask)
{
int i;

writel(0, addr);
for (i = 0; i < 32; i++)
- writel(GENMASK(i, 0), addr);
+ writel(GENMASK(i, 0) & ~reserved_mask, addr);
}

static int mt8192_scp_before_load(struct mtk_scp *scp)
@@ -391,11 +391,32 @@ static int mt8192_scp_before_load(struct mtk_scp *scp)
writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);

/* enable SRAM clock */
- mt8192_power_on_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_0);
- mt8192_power_on_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_1);
- mt8192_power_on_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_2);
- mt8192_power_on_sram(scp->reg_base + MT8192_L1TCM_SRAM_PDN);
- mt8192_power_on_sram(scp->reg_base + MT8192_CPU0_SRAM_PD);
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
+
+ /* enable MPU for all memory regions */
+ writel(0xff, scp->reg_base + MT8192_CORE0_MEM_ATT_PREDEF);
+
+ return 0;
+}
+
+static int mt8195_scp_before_load(struct mtk_scp *scp)
+{
+ /* clear SPM interrupt, SCP2SPM_IPC_CLR */
+ writel(0xff, scp->reg_base + MT8192_SCP2SPM_IPC_CLR);
+
+ writel(1, scp->reg_base + MT8192_CORE0_SW_RSTN_SET);
+
+ /* enable SRAM clock */
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
+ scp_sram_power_on(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
+ MT8195_L1TCM_SRAM_PDN_RESERVED_BITS);
+ scp_sram_power_on(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);

/* enable MPU for all memory regions */
writel(0xff, scp->reg_base + MT8192_CORE0_MEM_ATT_PREDEF);
@@ -551,11 +572,25 @@ static void mt8183_scp_stop(struct mtk_scp *scp)
static void mt8192_scp_stop(struct mtk_scp *scp)
{
/* Disable SRAM clock */
- mt8192_power_off_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_0);
- mt8192_power_off_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_1);
- mt8192_power_off_sram(scp->reg_base + MT8192_L2TCM_SRAM_PD_2);
- mt8192_power_off_sram(scp->reg_base + MT8192_L1TCM_SRAM_PDN);
- mt8192_power_off_sram(scp->reg_base + MT8192_CPU0_SRAM_PD);
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);
+
+ /* Disable SCP watchdog */
+ writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
+}
+
+static void mt8195_scp_stop(struct mtk_scp *scp)
+{
+ /* Disable SRAM clock */
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_0, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_1, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L2TCM_SRAM_PD_2, 0);
+ scp_sram_power_off(scp->reg_base + MT8192_L1TCM_SRAM_PDN,
+ MT8195_L1TCM_SRAM_PDN_RESERVED_BITS);
+ scp_sram_power_off(scp->reg_base + MT8192_CPU0_SRAM_PD, 0);

/* Disable SCP watchdog */
writel(0, scp->reg_base + MT8192_CORE0_WDT_CFG);
@@ -888,11 +923,11 @@ static const struct mtk_scp_of_data mt8192_of_data = {

static const struct mtk_scp_of_data mt8195_of_data = {
.scp_clk_get = mt8195_scp_clk_get,
- .scp_before_load = mt8192_scp_before_load,
+ .scp_before_load = mt8195_scp_before_load,
.scp_irq_handler = mt8192_scp_irq_handler,
.scp_reset_assert = mt8192_scp_reset_assert,
.scp_reset_deassert = mt8192_scp_reset_deassert,
- .scp_stop = mt8192_scp_stop,
+ .scp_stop = mt8195_scp_stop,
.scp_da_to_va = mt8192_scp_da_to_va,
.host_to_scp_reg = MT8192_GIPC_IN_SET,
.host_to_scp_int_bit = MT8192_HOST_IPC_INT_BIT,
--
2.18.0