Somehow we inverted the two, align with register definition to avoid further confusion.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 9bec270d0fa4..a1a889d1d7dc 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -235,7 +235,7 @@ static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value) * all changes to the MCP_CONFIG, MCP_CONTROL, MCP_CMDCTRL and MCP_PHYCTRL * need to be confirmed with a write to MCP_CONFIG_UPDATE */ -static int cdns_update_config(struct sdw_cdns *cdns) +static int cdns_config_update(struct sdw_cdns *cdns) { int ret;

@@ -838,7 +838,7 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns) CDNS_MCP_CONFIG_OP_NORMAL);

/* commit changes */ - return cdns_update_config(cdns); + return cdns_config_update(cdns); } EXPORT_SYMBOL(sdw_cdns_exit_reset);

@@ -1084,7 +1084,7 @@ int sdw_cdns_init(struct sdw_cdns *cdns, bool clock_stop_exit) cdns_writel(cdns, CDNS_MCP_CONFIG, val);

/* commit changes */ - return cdns_update_config(cdns); + return cdns_config_update(cdns); } EXPORT_SYMBOL(sdw_cdns_init);

From: Rander Wang rander.wang@intel.com

If master is in clock stop state, driver can't modify registers in master except the registers for clock stop setting.

Signed-off-by: Rander Wang rander.wang@intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 11 +++++++++++ drivers/soundwire/cadence_master.h | 2 ++ 2 files changed, 13 insertions(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 941809ea00a8..1bfdc1d4fcb1 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1207,6 +1207,17 @@ static const struct sdw_master_port_ops cdns_port_ops = { .dpn_port_enable_ch = cdns_port_enable, };

+/** + * sdw_cdns_is_clock_stop: Check clock status + * + * @cdns: Cadence instance + */ +bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns) +{ + return !!(cdns_readl(cdns, CDNS_MCP_STAT) & CDNS_MCP_STAT_CLK_STOP); +} +EXPORT_SYMBOL(sdw_cdns_is_clock_stop); + /** * sdw_cdns_probe() - Cadence probe routine * @cdns: Cadence instance diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h index 44e802bba702..691faa386889 100644 --- a/drivers/soundwire/cadence_master.h +++ b/drivers/soundwire/cadence_master.h @@ -144,6 +144,8 @@ int sdw_cdns_pdi_init(struct sdw_cdns *cdns, int sdw_cdns_exit_reset(struct sdw_cdns *cdns); int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns, bool state);

+bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns); + #ifdef CONFIG_DEBUG_FS void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root); #endif

From: Rander Wang rander.wang@intel.com

Add support for clock stop and restart, with two configuration parameters:

1) when entering the ClockStop mode, Slave-initiated wakes can be prevented.

2) When exiting the ClockStop mode, the caller can request a Bus Reset (either if all Slaves were configured in ClockStopMode1 or the Master IP lost context and enumeration is required)

The code handles the case where no Slaves are present by configuring the IP to treat COMMAND_IGNORED as success.

The exit_reset part can be dealt with in the caller, along with the required syncArm/syncGo sequence in multi-link mode.

Signed-off-by: Rander Wang rander.wang@intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 157 +++++++++++++++++++++++++++++ drivers/soundwire/cadence_master.h | 2 + 2 files changed, 159 insertions(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index d7f01d39767b..dc29556eaf94 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -231,6 +231,24 @@ static int cdns_clear_bit(struct sdw_cdns *cdns, int offset, u32 value) return -EAGAIN; }

+static int cdns_set_wait(struct sdw_cdns *cdns, int offset, u32 mask, u32 value) +{ + int timeout = 10; + u32 reg_read; + + /* Wait for bit to be set */ + do { + reg_read = readl(cdns->registers + offset); + if ((reg_read & mask) == value) + return 0; + + timeout--; + usleep_range(50, 100); + } while (timeout != 0); + + return -ETIMEDOUT; +} + /* * all changes to the MCP_CONFIG, MCP_CONTROL, MCP_CMDCTRL and MCP_PHYCTRL * need to be confirmed with a write to MCP_CONFIG_UPDATE @@ -1223,6 +1241,145 @@ bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns) } EXPORT_SYMBOL(sdw_cdns_is_clock_stop);

+/** + * sdw_cdns_clock_stop: Cadence clock stop configuration routine + * + * @cdns: Cadence instance + * @block_wake: prevent wakes if required by the platform + */ +int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake) +{ + bool slave_present = false; + struct sdw_slave *slave; + int ret; + + /* Check suspend status */ + if (sdw_cdns_is_clock_stop(cdns)) { + dev_dbg(cdns->dev, "Clock is already stopped\n"); + return 0; + } + + /* + * For specific platforms, it is required to be able to put + * master into a state in which it ignores wake-up trials + * in clock stop state + */ + if (block_wake) + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_BLOCK_WAKEUP, + CDNS_MCP_CONTROL_BLOCK_WAKEUP); + + list_for_each_entry(slave, &cdns->bus.slaves, node) { + if (slave->status == SDW_SLAVE_ATTACHED || + slave->status == SDW_SLAVE_ALERT) { + slave_present = true; + break; + } + } + + /* + * This CMD_ACCEPT should be used when there are no devices + * attached on the link when entering clock stop mode. If this is + * not set and there is a broadcast write then the command ignored + * will be treated as a failure + */ + if (!slave_present) + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_CMD_ACCEPT, + CDNS_MCP_CONTROL_CMD_ACCEPT); + else + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_CMD_ACCEPT, 0); + + /* commit changes */ + ret = cdns_config_update(cdns); + if (ret < 0) { + dev_err(cdns->dev, "%s: config_update failed\n", __func__); + return ret; + } + + /* Prepare slaves for clock stop */ + ret = sdw_bus_prep_clk_stop(&cdns->bus); + if (ret < 0) { + dev_err(cdns->dev, "prepare clock stop failed %d", ret); + return ret; + } + + /* + * Enter clock stop mode and only report errors if there are + * Slave devices present (ALERT or ATTACHED) + */ + ret = sdw_bus_clk_stop(&cdns->bus); + if (ret < 0 && slave_present && ret != -ENODATA) { + dev_err(cdns->dev, "bus clock stop failed %d", ret); + return ret; + } + + ret = cdns_set_wait(cdns, CDNS_MCP_STAT, + CDNS_MCP_STAT_CLK_STOP, + CDNS_MCP_STAT_CLK_STOP); + if (ret < 0) + dev_err(cdns->dev, "Clock stop failed %d\n", ret); + + return ret; +} +EXPORT_SYMBOL(sdw_cdns_clock_stop); + +/** + * sdw_cdns_clock_restart: Cadence PM clock restart configuration routine + * + * @cdns: Cadence instance + * @bus_reset: context may be lost while in low power modes and the bus + * may require a Severe Reset and re-enumeration after a wake. + */ +int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset) +{ + int ret; + + ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_CLK_STOP_CLR); + if (ret < 0) { + dev_err(cdns->dev, "Couldn't exit from clock stop\n"); + return ret; + } + + ret = cdns_set_wait(cdns, CDNS_MCP_STAT, CDNS_MCP_STAT_CLK_STOP, 0); + if (ret < 0) { + dev_err(cdns->dev, "clock stop exit failed %d\n", ret); + return ret; + } + + cdns_updatel(cdns, CDNS_MCP_CONTROL, + CDNS_MCP_CONTROL_BLOCK_WAKEUP, 0); + + /* + * clear CMD_ACCEPT so that the command ignored + * will be treated as a failure during a broadcast write + */ + cdns_updatel(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CMD_ACCEPT, 0); + + if (!bus_reset) { + + /* enable bus operations with clock and data */ + cdns_updatel(cdns, CDNS_MCP_CONFIG, + CDNS_MCP_CONFIG_OP, + CDNS_MCP_CONFIG_OP_NORMAL); + + ret = cdns_config_update(cdns); + if (ret < 0) { + dev_err(cdns->dev, "%s: config_update failed\n", __func__); + return ret; + } + + ret = sdw_bus_exit_clk_stop(&cdns->bus); + if (ret < 0) + dev_err(cdns->dev, "bus failed to exit clock stop %d\n", ret); + } + + return ret; +} +EXPORT_SYMBOL(sdw_cdns_clock_restart); + /** * sdw_cdns_probe() - Cadence probe routine * @cdns: Cadence instance diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h index 691faa386889..e8fa5c7e09f4 100644 --- a/drivers/soundwire/cadence_master.h +++ b/drivers/soundwire/cadence_master.h @@ -145,6 +145,8 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns); int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns, bool state);

bool sdw_cdns_is_clock_stop(struct sdw_cdns *cdns); +int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake); +int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset);

#ifdef CONFIG_DEBUG_FS void sdw_cdns_debugfs_init(struct sdw_cdns *cdns, struct dentry *root);

Intel QA reported a very rare case, possibly hardware-dependent, where a Slave can become UNATTACHED during a clock stop sequence, which leads to timeouts and failed suspend sequences.

This patch suppresses the handling of all Slave events while this transition happens. The two cases that matter are:

a) alerts: if the Slave wants to signal an alert condition, it can do so using the in-band wake, so there's almost no impact with this patch.

b) sync loss or imp-def reset: in those cases, bringing back the Slave to functional state requires a complete re-enumeration. It's better to just ignore this case and restart cleanly, rather than attempt a 'clean' suspend.

Validation results show the timeouts no longer visible with this patch.

GitHub issue: https://github.com/thesofproject/linux/issues/1678 Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 37e16199933c..613c63359413 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -865,6 +865,24 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns) } EXPORT_SYMBOL(sdw_cdns_exit_reset);

+/** + * sdw_cdns_enable_slave_interrupt() - Enable SDW slave interrupts + * @cdns: Cadence instance + * @state: boolean for true/false + */ +static void cdns_enable_slave_interrupts(struct sdw_cdns *cdns, bool state) +{ + u32 mask; + + mask = cdns_readl(cdns, CDNS_MCP_INTMASK); + if (state) + mask |= CDNS_MCP_INT_SLAVE_MASK; + else + mask &= ~CDNS_MCP_INT_SLAVE_MASK; + + cdns_writel(cdns, CDNS_MCP_INTMASK, mask); +} + /** * sdw_cdns_enable_interrupt() - Enable SDW interrupts * @cdns: Cadence instance @@ -1262,6 +1280,13 @@ int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake) return 0; }

+ /* + * Before entering clock stop we mask the Slave + * interrupts. This helps avoid having to deal with e.g. a + * Slave becoming UNATTACHED while the clock is being stopped + */ + cdns_enable_slave_interrupts(cdns, false); + /* * For specific platforms, it is required to be able to put * master into a state in which it ignores wake-up trials @@ -1339,6 +1364,9 @@ int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset) { int ret;

+ /* unmask Slave interrupts that were masked when stopping the clock */ + cdns_enable_slave_interrupts(cdns, true); + ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CLK_STOP_CLR); if (ret < 0) {

This helps isolate code and align with recommended programming flows

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 7d9fc2c645e3..fb697ff665f5 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1043,11 +1043,7 @@ static u32 cdns_set_initial_frame_shape(int n_rows, int n_cols) return val; }

-/** - * sdw_cdns_init() - Cadence initialization - * @cdns: Cadence instance - */ -int sdw_cdns_init(struct sdw_cdns *cdns) +static void cdns_init_clock_ctrl(struct sdw_cdns *cdns) { struct sdw_bus *bus = &cdns->bus; struct sdw_master_prop *prop = &bus->prop; @@ -1073,6 +1069,18 @@ int sdw_cdns_init(struct sdw_cdns *cdns) /* Set SSP interval to default value */ cdns_writel(cdns, CDNS_MCP_SSP_CTRL0, CDNS_DEFAULT_SSP_INTERVAL); cdns_writel(cdns, CDNS_MCP_SSP_CTRL1, CDNS_DEFAULT_SSP_INTERVAL); +} + +/** + * sdw_cdns_init() - Cadence initialization + * @cdns: Cadence instance + */ +int sdw_cdns_init(struct sdw_cdns *cdns) +{ + u32 val; + int ret; + + cdns_init_clock_ctrl(cdns);

/* reset msg_count to default value of FIFOLEVEL */ cdns->msg_count = cdns_readl(cdns, CDNS_MCP_FIFOLEVEL);

Follow hardware programming flows and add placeholder comment for multi-master mode.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 773341568d7e..9afce1f32076 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1097,20 +1097,22 @@ int sdw_cdns_init(struct sdw_cdns *cdns) /* Configure mcp config */ val = cdns_readl(cdns, CDNS_MCP_CONFIG);

- /* Set Max cmd retry to 15 */ - val |= CDNS_MCP_CONFIG_MCMD_RETRY; + /* Set cmd mode for Tx and Rx cmds */ + val &= ~CDNS_MCP_CONFIG_CMD;

- /* Set frame delay between PREQ and ping frame to 15 frames */ - val |= 0xF << SDW_REG_SHIFT(CDNS_MCP_CONFIG_MPREQ_DELAY); + /* Disable sniffer mode */ + val &= ~CDNS_MCP_CONFIG_SNIFFER;

/* Disable auto bus release */ val &= ~CDNS_MCP_CONFIG_BUS_REL;

- /* Disable sniffer mode */ - val &= ~CDNS_MCP_CONFIG_SNIFFER; + /* Multi-master support to be added here */

- /* Set cmd mode for Tx and Rx cmds */ - val &= ~CDNS_MCP_CONFIG_CMD; + /* Set frame delay between PREQ and ping frame to 15 frames */ + val |= 0xF << SDW_REG_SHIFT(CDNS_MCP_CONFIG_MPREQ_DELAY); + + /* Set Max cmd retry to 15 */ + val |= CDNS_MCP_CONFIG_MCMD_RETRY;

cdns_writel(cdns, CDNS_MCP_CONFIG, val);

The hardware default is 0x1F, and the existing code does an OR with 0xF. This is a no-op, remove.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 6adf41e3fdcf..420ad23c5530 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1107,8 +1107,7 @@ int sdw_cdns_init(struct sdw_cdns *cdns)

/* Multi-master support to be added here */

- /* Set frame delay between PREQ and ping frame to 15 frames */ - val |= 0xF << SDW_REG_SHIFT(CDNS_MCP_CONFIG_MPREQ_DELAY); + /* leave frame delay to hardware default of 0x1F */

/* Set Max cmd retry to 15 */ val |= CDNS_MCP_CONFIG_MCMD_RETRY;

Follow recommended flows, the BUS_RESET must be programmed before the UPDATE_CONFIG.

Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index c9fdd4deb4f5..55cf219cc908 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1074,7 +1074,6 @@ static void cdns_init_clock_ctrl(struct sdw_cdns *cdns) int sdw_cdns_init(struct sdw_cdns *cdns) { u32 val; - int ret;

cdns_init_clock_ctrl(cdns);

@@ -1113,8 +1112,8 @@ int sdw_cdns_init(struct sdw_cdns *cdns)

cdns_writel(cdns, CDNS_MCP_CONFIG, val);

- /* commit changes */ - return cdns_config_update(cdns); + /* changes will be committed later */ + return 0; } EXPORT_SYMBOL(sdw_cdns_init);

From: randerwang rander.wang@linux.intel.com

Driver should clear FIFO in PDI, or the previously stored sample data in FIFO will generate pop noise when stream is started. The soft reset bit will clear all the FIFO to zero and is self-cleared after that.

Signed-off-by: randerwang rander.wang@linux.intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com --- drivers/soundwire/cadence_master.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index eedc4cefdab0..ecd357d1c63d 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -1503,6 +1503,7 @@ void sdw_cdns_config_stream(struct sdw_cdns *cdns, cdns_updatel(cdns, offset, CDNS_PORTCTRL_DIRN, val);

val = pdi->num; + val |= CDNS_PDI_CONFIG_SOFT_RESET; val |= ((1 << ch) - 1) << SDW_REG_SHIFT(CDNS_PDI_CONFIG_CHANNEL); cdns_writel(cdns, CDNS_PDI_CONFIG(pdi->num), val); }