From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
Somehow the existing code is not aligned with the steps described in the documentation, refactor code and make sure the register programming sequences are correct. Also add missing power-up, power-down and wake capabilities (the last two are used in follow-up patches but introduced here for consistency).
Some of the SHIM registers exposed fields that are link specific, and in addition some of the power-related registers (SPA/CPA) take time to be updated. Uncontrolled access leads to timeouts or errors. Add a mutex, shared by all links, so that all accesses to such registers are serialized, and follow a pattern of read-modify-write.
This includes making sure SHIM_SYNC is programmed only once, before the first master is powered on. We use a 'shim_mask' field, shared between all links and protected by a mutex, to deal with power-up and power-down sequences.
Note that the SYNCPRD value is tied only to the XTAL value and not the current bus frequency or the frame rate.
BugLink: https://github.com/thesofproject/linux/issues/1555 Signed-off-by: Rander Wang rander.wang@intel.com Signed-off-by: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com Signed-off-by: Bard Liao yung-chuan.liao@linux.intel.com --- drivers/soundwire/intel.c | 241 +++++++++++++++++++++++----- drivers/soundwire/intel.h | 4 + drivers/soundwire/intel_init.c | 4 + include/linux/soundwire/sdw_intel.h | 2 + 4 files changed, 215 insertions(+), 36 deletions(-)
diff --git a/drivers/soundwire/intel.c b/drivers/soundwire/intel.c index 8c7ae07c0fe1..4792613e8e5a 100644 --- a/drivers/soundwire/intel.c +++ b/drivers/soundwire/intel.c @@ -46,7 +46,8 @@ #define SDW_SHIM_LCTL_SPA BIT(0) #define SDW_SHIM_LCTL_CPA BIT(8)
-#define SDW_SHIM_SYNC_SYNCPRD_VAL 0x176F +#define SDW_SHIM_SYNC_SYNCPRD_VAL_24 (24000 / SDW_CADENCE_GSYNC_KHZ - 1) +#define SDW_SHIM_SYNC_SYNCPRD_VAL_38_4 (38400 / SDW_CADENCE_GSYNC_KHZ - 1) #define SDW_SHIM_SYNC_SYNCPRD GENMASK(14, 0) #define SDW_SHIM_SYNC_SYNCCPU BIT(15) #define SDW_SHIM_SYNC_CMDSYNC_MASK GENMASK(19, 16) @@ -272,8 +273,46 @@ static int intel_link_power_up(struct sdw_intel *sdw) { unsigned int link_id = sdw->instance; void __iomem *shim = sdw->link_res->shim; + u32 *shim_mask = sdw->link_res->shim_mask; + struct sdw_bus *bus = &sdw->cdns.bus; + struct sdw_master_prop *prop = &bus->prop; int spa_mask, cpa_mask; - int link_control, ret; + int link_control; + int ret = 0; + u32 syncprd; + u32 sync_reg; + + mutex_lock(sdw->link_res->shim_lock); + + /* + * The hardware relies on an internal counter, typically 4kHz, + * to generate the SoundWire SSP - which defines a 'safe' + * synchronization point between commands and audio transport + * and allows for multi link synchronization. The SYNCPRD value + * is only dependent on the oscillator clock provided to + * the IP, so adjust based on _DSD properties reported in DSDT + * tables. The values reported are based on either 24MHz + * (CNL/CML) or 38.4 MHz (ICL/TGL+). + */ + if (prop->mclk_freq % 6000000) + syncprd = SDW_SHIM_SYNC_SYNCPRD_VAL_38_4; + else + syncprd = SDW_SHIM_SYNC_SYNCPRD_VAL_24; + + if (!*shim_mask) { + /* we first need to program the SyncPRD/CPU registers */ + dev_dbg(sdw->cdns.dev, + "%s: first link up, programming SYNCPRD\n", __func__); + + /* set SyncPRD period */ + sync_reg = intel_readl(shim, SDW_SHIM_SYNC); + sync_reg |= (syncprd << + SDW_REG_SHIFT(SDW_SHIM_SYNC_SYNCPRD)); + + /* Set SyncCPU bit */ + sync_reg |= SDW_SHIM_SYNC_SYNCCPU; + intel_writel(shim, SDW_SHIM_SYNC, sync_reg); + }
/* Link power up sequence */ link_control = intel_readl(shim, SDW_SHIM_LCTL); @@ -282,70 +321,182 @@ static int intel_link_power_up(struct sdw_intel *sdw) link_control |= spa_mask;
ret = intel_set_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask); - if (ret < 0) - return ret; + if (ret < 0) { + dev_err(sdw->cdns.dev, "Failed to power up link: %d\n", ret); + goto out; + } + + if (!*shim_mask) { + /* SyncCPU will change once link is active */ + ret = intel_wait_bit(shim, SDW_SHIM_SYNC, + SDW_SHIM_SYNC_SYNCCPU, 0); + if (ret < 0) { + dev_err(sdw->cdns.dev, + "Failed to set SHIM_SYNC: %d\n", ret); + goto out; + } + } + + *shim_mask |= BIT(link_id);
sdw->cdns.link_up = true; - return 0; +out: + mutex_unlock(sdw->link_res->shim_lock); + + return ret; }
-static int intel_shim_init(struct sdw_intel *sdw) +/* this needs to be called with shim_lock */ +static void intel_shim_glue_to_master_ip(struct sdw_intel *sdw) { void __iomem *shim = sdw->link_res->shim; unsigned int link_id = sdw->instance; - int sync_reg, ret; - u16 ioctl = 0, act = 0; - - /* Initialize Shim */ - ioctl |= SDW_SHIM_IOCTL_BKE; - intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); - - ioctl |= SDW_SHIM_IOCTL_WPDD; - intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); - - ioctl |= SDW_SHIM_IOCTL_DO; - intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); - - ioctl |= SDW_SHIM_IOCTL_DOE; - intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + u16 ioctl;
/* Switch to MIP from Glue logic */ ioctl = intel_readw(shim, SDW_SHIM_IOCTL(link_id));
ioctl &= ~(SDW_SHIM_IOCTL_DOE); intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15);
ioctl &= ~(SDW_SHIM_IOCTL_DO); intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15);
ioctl |= (SDW_SHIM_IOCTL_MIF); intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15);
ioctl &= ~(SDW_SHIM_IOCTL_BKE); ioctl &= ~(SDW_SHIM_IOCTL_COE); + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15); + + /* at this point Master IP has full control of the I/Os */ +} + +/* this needs to be called with shim_lock */ +static void intel_shim_master_ip_to_glue(struct sdw_intel *sdw) +{ + unsigned int link_id = sdw->instance; + void __iomem *shim = sdw->link_res->shim; + u16 ioctl; + + /* Glue logic */ + ioctl = intel_readw(shim, SDW_SHIM_IOCTL(link_id)); + ioctl |= SDW_SHIM_IOCTL_BKE; + ioctl |= SDW_SHIM_IOCTL_COE; + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15);
+ ioctl &= ~(SDW_SHIM_IOCTL_MIF); intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15); + + /* at this point Integration Glue has full control of the I/Os */ +} + +static int intel_shim_init(struct sdw_intel *sdw, bool clock_stop) +{ + void __iomem *shim = sdw->link_res->shim; + unsigned int link_id = sdw->instance; + int ret = 0; + u16 ioctl = 0, act = 0; + + mutex_lock(sdw->link_res->shim_lock); + + /* Initialize Shim */ + ioctl |= SDW_SHIM_IOCTL_BKE; + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15); + + ioctl |= SDW_SHIM_IOCTL_WPDD; + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15); + + ioctl |= SDW_SHIM_IOCTL_DO; + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15); + + ioctl |= SDW_SHIM_IOCTL_DOE; + intel_writew(shim, SDW_SHIM_IOCTL(link_id), ioctl); + usleep_range(10, 15); + + intel_shim_glue_to_master_ip(sdw);
act |= 0x1 << SDW_REG_SHIFT(SDW_SHIM_CTMCTL_DOAIS); act |= SDW_SHIM_CTMCTL_DACTQE; act |= SDW_SHIM_CTMCTL_DODS; intel_writew(shim, SDW_SHIM_CTMCTL(link_id), act); + usleep_range(10, 15);
- /* Now set SyncPRD period */ - sync_reg = intel_readl(shim, SDW_SHIM_SYNC); - sync_reg |= (SDW_SHIM_SYNC_SYNCPRD_VAL << - SDW_REG_SHIFT(SDW_SHIM_SYNC_SYNCPRD)); - - /* Set SyncCPU bit */ - sync_reg |= SDW_SHIM_SYNC_SYNCCPU; - ret = intel_clear_bit(shim, SDW_SHIM_SYNC, sync_reg, - SDW_SHIM_SYNC_SYNCCPU); - if (ret < 0) - dev_err(sdw->cdns.dev, "Failed to set sync period: %d\n", ret); + mutex_unlock(sdw->link_res->shim_lock);
return ret; }
+static void __maybe_unused intel_shim_wake(struct sdw_intel *sdw, bool wake_enable) +{ + void __iomem *shim = sdw->link_res->shim; + unsigned int link_id = sdw->instance; + u16 wake_en, wake_sts; + + mutex_lock(sdw->link_res->shim_lock); + wake_en = intel_readw(shim, SDW_SHIM_WAKEEN); + + if (wake_enable) { + /* Enable the wakeup */ + wake_en |= (SDW_SHIM_WAKEEN_ENABLE << link_id); + intel_writew(shim, SDW_SHIM_WAKEEN, wake_en); + } else { + /* Disable the wake up interrupt */ + wake_en &= ~(SDW_SHIM_WAKEEN_ENABLE << link_id); + intel_writew(shim, SDW_SHIM_WAKEEN, wake_en); + + /* Clear wake status */ + wake_sts = intel_readw(shim, SDW_SHIM_WAKESTS); + wake_sts |= (SDW_SHIM_WAKEEN_ENABLE << link_id); + intel_writew(shim, SDW_SHIM_WAKESTS_STATUS, wake_sts); + } + mutex_unlock(sdw->link_res->shim_lock); +} + +static int __maybe_unused intel_link_power_down(struct sdw_intel *sdw) +{ + int link_control, spa_mask, cpa_mask; + unsigned int link_id = sdw->instance; + void __iomem *shim = sdw->link_res->shim; + u32 *shim_mask = sdw->link_res->shim_mask; + int ret = 0; + + mutex_lock(sdw->link_res->shim_lock); + + intel_shim_master_ip_to_glue(sdw); + + /* Link power down sequence */ + link_control = intel_readl(shim, SDW_SHIM_LCTL); + spa_mask = ~(SDW_SHIM_LCTL_SPA << link_id); + cpa_mask = (SDW_SHIM_LCTL_CPA << link_id); + link_control &= spa_mask; + + ret = intel_clear_bit(shim, SDW_SHIM_LCTL, link_control, cpa_mask); + + if (!(*shim_mask & BIT(link_id))) + dev_err(sdw->cdns.dev, + "%s: Unbalanced power-up/down calls\n", __func__); + + *shim_mask &= ~BIT(link_id); + + mutex_unlock(sdw->link_res->shim_lock); + + if (ret < 0) + return ret; + + sdw->cdns.link_up = false; + return 0; +} + /* * PDI routines */ @@ -566,11 +717,15 @@ static int intel_pre_bank_switch(struct sdw_bus *bus) if (!bus->multi_link) return 0;
+ mutex_lock(sdw->link_res->shim_lock); + /* Read SYNC register */ sync_reg = intel_readl(shim, SDW_SHIM_SYNC); sync_reg |= SDW_SHIM_SYNC_CMDSYNC << sdw->instance; intel_writel(shim, SDW_SHIM_SYNC, sync_reg);
+ mutex_unlock(sdw->link_res->shim_lock); + return 0; }
@@ -585,6 +740,8 @@ static int intel_post_bank_switch(struct sdw_bus *bus) if (!bus->multi_link) return 0;
+ mutex_lock(sdw->link_res->shim_lock); + /* Read SYNC register */ sync_reg = intel_readl(shim, SDW_SHIM_SYNC);
@@ -596,9 +753,10 @@ static int intel_post_bank_switch(struct sdw_bus *bus) * * So, set the SYNCGO bit only if CMDSYNC bit is set for any Master. */ - if (!(sync_reg & SDW_SHIM_SYNC_CMDSYNC_MASK)) - return 0; - + if (!(sync_reg & SDW_SHIM_SYNC_CMDSYNC_MASK)) { + ret = 0; + goto unlock; + } /* * Set SyncGO bit to synchronously trigger a bank switch for * all the masters. A write to SYNCGO bit clears CMDSYNC bit for all @@ -608,6 +766,9 @@ static int intel_post_bank_switch(struct sdw_bus *bus)
ret = intel_clear_bit(shim, SDW_SHIM_SYNC, sync_reg, SDW_SHIM_SYNC_SYNCGO); +unlock: + mutex_unlock(sdw->link_res->shim_lock); + if (ret < 0) dev_err(sdw->cdns.dev, "Post bank switch failed: %d\n", ret);
@@ -1011,9 +1172,17 @@ static struct sdw_master_ops sdw_intel_ops = {
static int intel_init(struct sdw_intel *sdw) { + bool clock_stop; + /* Initialize shim and controller */ intel_link_power_up(sdw); - intel_shim_init(sdw); + + clock_stop = sdw_cdns_is_clock_stop(&sdw->cdns); + + intel_shim_init(sdw, clock_stop); + + if (clock_stop) + return 0;
return sdw_cdns_init(&sdw->cdns); } diff --git a/drivers/soundwire/intel.h b/drivers/soundwire/intel.h index 694117370ac3..d6bdd4d63e08 100644 --- a/drivers/soundwire/intel.h +++ b/drivers/soundwire/intel.h @@ -15,6 +15,8 @@ * @irq: Interrupt line * @ops: Shim callback ops * @dev: device implementing hw_params and free callbacks + * @shim_lock: mutex to handle access to shared SHIM registers + * @shim_mask: global pointer to check SHIM register initialization */ struct sdw_intel_link_res { struct platform_device *pdev; @@ -25,6 +27,8 @@ struct sdw_intel_link_res { int irq; const struct sdw_intel_ops *ops; struct device *dev; + struct mutex *shim_lock; /* protect shared registers */ + u32 *shim_mask; };
struct sdw_intel { diff --git a/drivers/soundwire/intel_init.c b/drivers/soundwire/intel_init.c index 3f2e884b4f6d..f50a93130d12 100644 --- a/drivers/soundwire/intel_init.c +++ b/drivers/soundwire/intel_init.c @@ -180,6 +180,7 @@ static struct sdw_intel_ctx ctx->mmio_base = res->mmio_base; ctx->link_mask = res->link_mask; ctx->handle = res->handle; + mutex_init(&ctx->shim_lock);
link = ctx->links; link_mask = ctx->link_mask; @@ -201,6 +202,9 @@ static struct sdw_intel_ctx link->ops = res->ops; link->dev = res->dev;
+ link->shim_lock = &ctx->shim_lock; + link->shim_mask = &ctx->shim_mask; + memset(&pdevinfo, 0, sizeof(pdevinfo));
pdevinfo.parent = res->parent; diff --git a/include/linux/soundwire/sdw_intel.h b/include/linux/soundwire/sdw_intel.h index 979b41b5dcb4..120ffddc03d2 100644 --- a/include/linux/soundwire/sdw_intel.h +++ b/include/linux/soundwire/sdw_intel.h @@ -115,6 +115,7 @@ struct sdw_intel_slave_id { * links * @link_list: list to handle interrupts across all links * @shim_lock: mutex to handle concurrent rmw access to shared SHIM registers. + * @shim_mask: flags to track initialization of SHIM shared registers */ struct sdw_intel_ctx { int count; @@ -126,6 +127,7 @@ struct sdw_intel_ctx { struct sdw_intel_slave_id *ids; struct list_head link_list; struct mutex shim_lock; /* lock for access to shared SHIM registers */ + u32 shim_mask; };
/**