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soundwire: intel: revisit SHIM programming sequences.

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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>
Link: https://lore.kernel.org/r/20200716150947.22119-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Pierre-Louis Bossart 2020-07-16 23:09:40 +08:00 committed by Vinod Koul
parent 7d2845d58d
commit 4a17c441c7
4 changed files with 216 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

247
drivers/soundwire/intel.c
View File

@ -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;
sdw->cdns.link_up = true;
return 0;
if (ret < 0) {
dev_err(sdw->cdns.dev, "Failed to power up link: %d\n", ret);
goto out;
}
static int intel_shim_init(struct sdw_intel *sdw)
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;
out:
mutex_unlock(sdw->link_res->shim_lock);
return ret;
}
/* 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);
}

4
drivers/soundwire/intel.h
View File

@ -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 {

4
drivers/soundwire/intel_init.c
View File

@ -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;

2
include/linux/soundwire/sdw_intel.h
View File

@ -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;
};
/**