static int kempld_wdt_probe_stages(struct watchdog_device *wdd)
{
struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
struct kempld_device_data *pld = wdt_data->pld;
struct kempld_wdt_stage *pretimeout_stage;
struct kempld_wdt_stage *timeout_stage;
u8 index, data, data_orig;
u32 mask;
int i, j;
pretimeout_stage = &wdt_data->stage[STAGE_PRETIMEOUT];
timeout_stage = &wdt_data->stage[STAGE_TIMEOUT];
pretimeout_stage->mask = 0;
timeout_stage->mask = 0;
for (i = 0; i < 3; i++) {
index = KEMPLD_WDT_STAGE_TIMEOUT(i);
mask = 0;
kempld_get_mutex(pld);
/* Probe each byte individually. */
for (j = 0; j < 4; j++) {
data_orig = kempld_read8(pld, index + j);
kempld_write8(pld, index + j, 0x00);
data = kempld_read8(pld, index + j);
/* A failed write means this byte is reserved */
if (data != 0x00)
break;
kempld_write8(pld, index + j, data_orig);
mask |= 0xff << (j * 8);
}
kempld_release_mutex(pld);
/* Assign available stages to timeout and pretimeout */
if (!timeout_stage->mask) {
timeout_stage->mask = mask;
timeout_stage->id = i;
} else {
if (pld->feature_mask & KEMPLD_FEATURE_BIT_NMI) {
pretimeout_stage->mask = timeout_stage->mask;
timeout_stage->mask = mask;
pretimeout_stage->id = timeout_stage->id;
timeout_stage->id = i;
}
break;
}
}
if (!timeout_stage->mask)
return -ENODEV;
return 0;
}
static int kempld_get_info_generic(struct kempld_device_data *pld)
{
u16 version;
u8 spec;
kempld_get_mutex(pld);
version = kempld_read16(pld, KEMPLD_VERSION);
spec = kempld_read8(pld, KEMPLD_SPEC);
pld->info.buildnr = kempld_read16(pld, KEMPLD_BUILDNR);
pld->info.minor = KEMPLD_VERSION_GET_MINOR(version);
pld->info.major = KEMPLD_VERSION_GET_MAJOR(version);
pld->info.number = KEMPLD_VERSION_GET_NUMBER(version);
pld->info.type = KEMPLD_VERSION_GET_TYPE(version);
if (spec == 0xff) {
pld->info.spec_minor = 0;
pld->info.spec_major = 1;
} else {
pld->info.spec_minor = KEMPLD_SPEC_GET_MINOR(spec);
pld->info.spec_major = KEMPLD_SPEC_GET_MAJOR(spec);
}
if (pld->info.spec_major > 0)
pld->feature_mask = kempld_read16(pld, KEMPLD_FEATURE);
else
pld->feature_mask = 0;
kempld_release_mutex(pld);
return 0;
}
/*
* kempld_get_mutex must be called prior to calling this function.
*/
static unsigned int kempld_wdt_get_timeout(struct kempld_wdt_data *wdt_data,
struct kempld_wdt_stage *stage)
{
struct kempld_device_data *pld = wdt_data->pld;
unsigned int timeout;
u64 stage_timeout;
u32 prescaler;
u32 remainder;
u8 stage_cfg;
if (!stage->mask)
return 0;
stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id));
stage_timeout = kempld_read32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id));
prescaler = kempld_prescaler[STAGE_CFG_GET_PRESCALER(stage_cfg)];
stage_timeout = (stage_timeout & stage->mask) * prescaler;
remainder = do_div(stage_timeout, pld->pld_clock);
if (remainder)
stage_timeout++;
timeout = stage_timeout;
WARN_ON_ONCE(timeout != stage_timeout);
return timeout;
}
static int kempld_wdt_set_stage_timeout(struct kempld_wdt_data *wdt_data,
struct kempld_wdt_stage *stage,
unsigned int timeout)
{
struct kempld_device_data *pld = wdt_data->pld;
u32 prescaler = kempld_prescaler[PRESCALER_21];
u64 stage_timeout64;
u32 stage_timeout;
u32 remainder;
u8 stage_cfg;
if (!stage)
return -EINVAL;
stage_timeout64 = (u64)timeout * pld->pld_clock;
remainder = do_div(stage_timeout64, prescaler);
if (remainder)
stage_timeout64++;
if (stage_timeout64 > stage->mask)
return -EINVAL;
stage_timeout = stage_timeout64 & stage->mask;
kempld_get_mutex(pld);
stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id));
stage_cfg &= ~STAGE_CFG_PRESCALER_MASK;
stage_cfg |= STAGE_CFG_SET_PRESCALER(PRESCALER_21);
kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg);
kempld_write32(pld, KEMPLD_WDT_STAGE_TIMEOUT(stage->id),
stage_timeout);
kempld_release_mutex(pld);
return 0;
}
static int kempld_wdt_set_stage_action(struct kempld_wdt_data *wdt_data,
struct kempld_wdt_stage *stage,
u8 action)
{
struct kempld_device_data *pld = wdt_data->pld;
u8 stage_cfg;
if (!stage || !stage->mask)
return -EINVAL;
kempld_get_mutex(pld);
stage_cfg = kempld_read8(pld, KEMPLD_WDT_STAGE_CFG(stage->id));
stage_cfg &= ~STAGE_CFG_ACTION_MASK;
stage_cfg |= (action & STAGE_CFG_ACTION_MASK);
if (action == ACTION_RESET)
stage_cfg |= STAGE_CFG_ASSERT;
else
stage_cfg &= ~STAGE_CFG_ASSERT;
kempld_write8(pld, KEMPLD_WDT_STAGE_CFG(stage->id), stage_cfg);
kempld_release_mutex(pld);
return 0;
}
static int kempld_wdt_probe(struct platform_device *pdev)
{
struct kempld_device_data *pld = dev_get_drvdata(pdev->dev.parent);
struct kempld_wdt_data *wdt_data;
struct device *dev = &pdev->dev;
struct watchdog_device *wdd;
u8 status;
int ret = 0;
wdt_data = devm_kzalloc(dev, sizeof(*wdt_data), GFP_KERNEL);
if (!wdt_data)
return -ENOMEM;
wdt_data->pld = pld;
wdd = &wdt_data->wdd;
wdd->parent = dev;
kempld_get_mutex(pld);
status = kempld_read8(pld, KEMPLD_WDT_CFG);
kempld_release_mutex(pld);
/* Enable nowayout if watchdog is already locked */
if (status & (KEMPLD_WDT_CFG_ENABLE_LOCK |
KEMPLD_WDT_CFG_GLOBAL_LOCK)) {
if (!nowayout)
dev_warn(dev,
"Forcing nowayout - watchdog lock enabled!\n");
nowayout = true;
}
wdd->info = &kempld_wdt_info;
wdd->ops = &kempld_wdt_ops;
watchdog_set_drvdata(wdd, wdt_data);
watchdog_set_nowayout(wdd, nowayout);
ret = kempld_wdt_probe_stages(wdd);
if (ret)
return ret;
kempld_wdt_set_timeout(wdd, timeout);
kempld_wdt_set_pretimeout(wdd, pretimeout);
/* Check if watchdog is already enabled */
if (status & KEMPLD_WDT_CFG_ENABLE) {
/* Get current watchdog settings */
kempld_wdt_update_timeouts(wdt_data);
dev_info(dev, "Watchdog was already enabled\n");
}
platform_set_drvdata(pdev, wdt_data);
ret = watchdog_register_device(wdd);
if (ret)
return ret;
dev_info(dev, "Watchdog registered with %ds timeout\n", wdd->timeout);
return 0;
}
static int kempld_wdt_stop(struct watchdog_device *wdd)
{
struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
struct kempld_device_data *pld = wdt_data->pld;
u8 status;
kempld_get_mutex(pld);
status = kempld_read8(pld, KEMPLD_WDT_CFG);
status &= ~KEMPLD_WDT_CFG_ENABLE;
kempld_write8(pld, KEMPLD_WDT_CFG, status);
status = kempld_read8(pld, KEMPLD_WDT_CFG);
kempld_release_mutex(pld);
/* Check if the watchdog was disabled */
if (status & KEMPLD_WDT_CFG_ENABLE)
return -EACCES;
return 0;
}
static int kempld_gpio_get_bit(struct kempld_device_data *pld, u8 reg, u8 bit)
{
u8 status;
kempld_get_mutex(pld);
status = kempld_read8(pld, reg);
kempld_release_mutex(pld);
return !!(status & KEMPLD_GPIO_MASK(bit));
}
/*
* Set or clear GPIO bit
* kempld_get_mutex must be called prior to calling this function.
*/
static void kempld_gpio_bitop(struct kempld_device_data *pld,
u8 reg, u8 bit, u8 val)
{
u8 status;
status = kempld_read8(pld, reg);
if (val)
status |= KEMPLD_GPIO_MASK(bit);
else
status &= ~KEMPLD_GPIO_MASK(bit);
kempld_write8(pld, reg, status);
}
static int kempld_wdt_start(struct watchdog_device *wdd)
{
struct kempld_wdt_data *wdt_data = watchdog_get_drvdata(wdd);
struct kempld_device_data *pld = wdt_data->pld;
u8 status;
int ret;
ret = kempld_wdt_set_timeout(wdd, wdd->timeout);
if (ret)
return ret;
kempld_get_mutex(pld);
status = kempld_read8(pld, KEMPLD_WDT_CFG);
status |= KEMPLD_WDT_CFG_ENABLE;
kempld_write8(pld, KEMPLD_WDT_CFG, status);
status = kempld_read8(pld, KEMPLD_WDT_CFG);
kempld_release_mutex(pld);
/* Check if the watchdog was enabled */
if (!(status & KEMPLD_WDT_CFG_ENABLE))
return -EACCES;
return 0;
}
/* Disable watchdog if it is active during suspend */
static int kempld_wdt_suspend(struct platform_device *pdev,
pm_message_t message)
{
struct kempld_wdt_data *wdt_data = platform_get_drvdata(pdev);
struct kempld_device_data *pld = wdt_data->pld;
struct watchdog_device *wdd = &wdt_data->wdd;
kempld_get_mutex(pld);
wdt_data->pm_status_store = kempld_read8(pld, KEMPLD_WDT_CFG);
kempld_release_mutex(pld);
kempld_wdt_update_timeouts(wdt_data);
if (wdt_data->pm_status_store & KEMPLD_WDT_CFG_ENABLE)
return kempld_wdt_stop(wdd);
return 0;
}
/**
* kempld_read16 - read 16 bit register
* @pld: kempld_device_data structure describing the PLD
* @index: register index on the chip
*
* kempld_get_mutex must be called prior to calling this function.
*/
u16 kempld_read16(struct kempld_device_data *pld, u8 index)
{
return kempld_read8(pld, index) | kempld_read8(pld, index + 1) << 8;
}
