#include <linux/io.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
+#include <linux/cpu_pm.h>
#include <linux/delay.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
#include <linux/sys_soc.h>
+#include <linux/timekeeping.h>
#include <linux/iopoll.h>
#include <linux/platform_data/ti-sysc.h>
struct list_head node;
};
+struct sysc_module {
+ struct sysc *ddata;
+ struct list_head node;
+};
+
struct sysc_soc_info {
unsigned long general_purpose:1;
enum sysc_soc soc;
- struct mutex list_lock; /* disabled modules list lock */
+ struct mutex list_lock; /* disabled and restored modules list lock */
struct list_head disabled_modules;
+ struct list_head restored_modules;
+ struct notifier_block nb;
};
enum sysc_clocks {
struct ti_sysc_cookie cookie;
const char *name;
u32 revision;
+ u32 sysconfig;
unsigned int reserved:1;
unsigned int enabled:1;
unsigned int needs_resume:1;
static void sysc_parse_dts_quirks(struct sysc *ddata, struct device_node *np,
bool is_child);
+static int sysc_reset(struct sysc *ddata);
static void sysc_write(struct sysc *ddata, int offset, u32 value)
{
return sysc_read(ddata, offset);
}
-/* Poll on reset status */
-static int sysc_wait_softreset(struct sysc *ddata)
+static int sysc_poll_reset_sysstatus(struct sysc *ddata)
{
- u32 sysc_mask, syss_done, rstval;
- int syss_offset, error = 0;
-
- if (ddata->cap->regbits->srst_shift < 0)
- return 0;
-
- syss_offset = ddata->offsets[SYSC_SYSSTATUS];
- sysc_mask = BIT(ddata->cap->regbits->srst_shift);
+ int error, retries;
+ u32 syss_done, rstval;
if (ddata->cfg.quirks & SYSS_QUIRK_RESETDONE_INVERTED)
syss_done = 0;
else
syss_done = ddata->cfg.syss_mask;
- if (syss_offset >= 0) {
+ if (likely(!timekeeping_suspended)) {
error = readx_poll_timeout_atomic(sysc_read_sysstatus, ddata,
rstval, (rstval & ddata->cfg.syss_mask) ==
syss_done, 100, MAX_MODULE_SOFTRESET_WAIT);
+ } else {
+ retries = MAX_MODULE_SOFTRESET_WAIT;
+ while (retries--) {
+ rstval = sysc_read_sysstatus(ddata);
+ if ((rstval & ddata->cfg.syss_mask) == syss_done)
+ return 0;
+ udelay(2); /* Account for udelay flakeyness */
+ }
+ error = -ETIMEDOUT;
+ }
+
+ return error;
+}
+
+static int sysc_poll_reset_sysconfig(struct sysc *ddata)
+{
+ int error, retries;
+ u32 sysc_mask, rstval;
- } else if (ddata->cfg.quirks & SYSC_QUIRK_RESET_STATUS) {
+ sysc_mask = BIT(ddata->cap->regbits->srst_shift);
+
+ if (likely(!timekeeping_suspended)) {
error = readx_poll_timeout_atomic(sysc_read_sysconfig, ddata,
rstval, !(rstval & sysc_mask),
100, MAX_MODULE_SOFTRESET_WAIT);
+ } else {
+ retries = MAX_MODULE_SOFTRESET_WAIT;
+ while (retries--) {
+ rstval = sysc_read_sysconfig(ddata);
+ if (!(rstval & sysc_mask))
+ return 0;
+ udelay(2); /* Account for udelay flakeyness */
+ }
+ error = -ETIMEDOUT;
}
return error;
}
+/* Poll on reset status */
+static int sysc_wait_softreset(struct sysc *ddata)
+{
+ int syss_offset, error = 0;
+
+ if (ddata->cap->regbits->srst_shift < 0)
+ return 0;
+
+ syss_offset = ddata->offsets[SYSC_SYSSTATUS];
+
+ if (syss_offset >= 0)
+ error = sysc_poll_reset_sysstatus(ddata);
+ else if (ddata->cfg.quirks & SYSC_QUIRK_RESET_STATUS)
+ error = sysc_poll_reset_sysconfig(ddata);
+
+ return error;
+}
+
static int sysc_add_named_clock_from_child(struct sysc *ddata,
const char *name,
const char *optfck_name)
best_mode = fls(ddata->cfg.midlemodes) - 1;
if (best_mode > SYSC_IDLE_MASK) {
dev_err(dev, "%s: invalid midlemode\n", __func__);
- return -EINVAL;
+ error = -EINVAL;
+ goto save_context;
}
if (ddata->cfg.quirks & SYSC_QUIRK_SWSUP_MSTANDBY)
sysc_write_sysconfig(ddata, reg);
}
- /* Flush posted write */
- sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
+ error = 0;
+
+save_context:
+ /* Save context and flush posted write */
+ ddata->sysconfig = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
if (ddata->module_enable_quirk)
ddata->module_enable_quirk(ddata);
- return 0;
+ return error;
}
static int sysc_best_idle_mode(u32 idlemodes, u32 *best_mode)
set_sidle:
/* Set SIDLE mode */
idlemodes = ddata->cfg.sidlemodes;
- if (!idlemodes || regbits->sidle_shift < 0)
- return 0;
+ if (!idlemodes || regbits->sidle_shift < 0) {
+ ret = 0;
+ goto save_context;
+ }
if (ddata->cfg.quirks & SYSC_QUIRK_SWSUP_SIDLE) {
best_mode = SYSC_IDLE_FORCE;
ret = sysc_best_idle_mode(idlemodes, &best_mode);
if (ret) {
dev_err(dev, "%s: invalid sidlemode\n", __func__);
- return ret;
+ ret = -EINVAL;
+ goto save_context;
}
}
reg |= 1 << regbits->autoidle_shift;
sysc_write_sysconfig(ddata, reg);
- /* Flush posted write */
- sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
+ ret = 0;
- return 0;
+save_context:
+ /* Save context and flush posted write */
+ ddata->sysconfig = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
+
+ return ret;
}
static int __maybe_unused sysc_runtime_suspend_legacy(struct device *dev,
return error;
}
+/*
+ * Checks if device context was lost. Assumes the sysconfig register value
+ * after lost context is different from the configured value. Only works for
+ * enabled devices.
+ *
+ * Eventually we may want to also add support to using the context lost
+ * registers that some SoCs have.
+ */
+static int sysc_check_context(struct sysc *ddata)
+{
+ u32 reg;
+
+ if (!ddata->enabled)
+ return -ENODATA;
+
+ reg = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);
+ if (reg == ddata->sysconfig)
+ return 0;
+
+ return -EACCES;
+}
+
static int sysc_reinit_module(struct sysc *ddata, bool leave_enabled)
{
struct device *dev = ddata->dev;
int error;
- /* Disable target module if it is enabled */
if (ddata->enabled) {
+ /* Nothing to do if enabled and context not lost */
+ error = sysc_check_context(ddata);
+ if (!error)
+ return 0;
+
+ /* Disable target module if it is enabled */
error = sysc_runtime_suspend(dev);
if (error)
dev_warn(dev, "reinit suspend failed: %i\n", error);
if (error)
dev_warn(dev, "reinit resume failed: %i\n", error);
+ /* Some modules like am335x gpmc need reset and restore of sysconfig */
+ if (ddata->cfg.quirks & SYSC_QUIRK_RESET_ON_CTX_LOST) {
+ error = sysc_reset(ddata);
+ if (error)
+ dev_warn(dev, "reinit reset failed: %i\n", error);
+
+ sysc_write_sysconfig(ddata, ddata->sysconfig);
+ }
+
if (leave_enabled)
return error;
}
};
+/* Caller needs to take list_lock if ever used outside of cpu_pm */
+static void sysc_reinit_modules(struct sysc_soc_info *soc)
+{
+ struct sysc_module *module;
+ struct list_head *pos;
+ struct sysc *ddata;
+ int error = 0;
+
+ list_for_each(pos, &sysc_soc->restored_modules) {
+ module = list_entry(pos, struct sysc_module, node);
+ ddata = module->ddata;
+ error = sysc_reinit_module(ddata, ddata->enabled);
+ }
+}
+
+/**
+ * sysc_context_notifier - optionally reset and restore module after idle
+ * @nb: notifier block
+ * @cmd: unused
+ * @v: unused
+ *
+ * Some interconnect target modules need to be restored, or reset and restored
+ * on CPU_PM CPU_PM_CLUSTER_EXIT notifier. This is needed at least for am335x
+ * OTG and GPMC target modules even if the modules are unused.
+ */
+static int sysc_context_notifier(struct notifier_block *nb, unsigned long cmd,
+ void *v)
+{
+ struct sysc_soc_info *soc;
+
+ soc = container_of(nb, struct sysc_soc_info, nb);
+
+ switch (cmd) {
+ case CPU_CLUSTER_PM_ENTER:
+ break;
+ case CPU_CLUSTER_PM_ENTER_FAILED: /* No need to restore context */
+ break;
+ case CPU_CLUSTER_PM_EXIT:
+ sysc_reinit_modules(soc);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+/**
+ * sysc_add_restored - optionally add reset and restore quirk hanlling
+ * @ddata: device data
+ */
+static void sysc_add_restored(struct sysc *ddata)
+{
+ struct sysc_module *restored_module;
+
+ restored_module = kzalloc(sizeof(*restored_module), GFP_KERNEL);
+ if (!restored_module)
+ return;
+
+ restored_module->ddata = ddata;
+
+ mutex_lock(&sysc_soc->list_lock);
+
+ list_add(&restored_module->node, &sysc_soc->restored_modules);
+
+ if (sysc_soc->nb.notifier_call)
+ goto out_unlock;
+
+ sysc_soc->nb.notifier_call = sysc_context_notifier;
+ cpu_pm_register_notifier(&sysc_soc->nb);
+
+out_unlock:
+ mutex_unlock(&sysc_soc->list_lock);
+}
+
/**
* sysc_legacy_idle_quirk - handle children in omap_device compatible way
* @ddata: device driver data
}
/*
- * One time init to detect the booted SoC and disable unavailable features.
+ * One time init to detect the booted SoC, disable unavailable features
+ * and initialize list for optional cpu_pm notifier.
+ *
* Note that we initialize static data shared across all ti-sysc instances
* so ddata is only used for SoC type. This can be called from module_init
* once we no longer need to rely on platform data.
*/
-static int sysc_init_soc(struct sysc *ddata)
+static int sysc_init_static_data(struct sysc *ddata)
{
const struct soc_device_attribute *match;
struct ti_sysc_platform_data *pdata;
mutex_init(&sysc_soc->list_lock);
INIT_LIST_HEAD(&sysc_soc->disabled_modules);
+ INIT_LIST_HEAD(&sysc_soc->restored_modules);
sysc_soc->general_purpose = true;
pdata = dev_get_platdata(ddata->dev);
return 0;
}
-static void sysc_cleanup_soc(void)
+static void sysc_cleanup_static_data(void)
{
+ struct sysc_module *restored_module;
struct sysc_address *disabled_module;
struct list_head *pos, *tmp;
if (!sysc_soc)
return;
+ if (sysc_soc->nb.notifier_call)
+ cpu_pm_unregister_notifier(&sysc_soc->nb);
+
mutex_lock(&sysc_soc->list_lock);
+ list_for_each_safe(pos, tmp, &sysc_soc->restored_modules) {
+ restored_module = list_entry(pos, struct sysc_module, node);
+ list_del(pos);
+ kfree(restored_module);
+ }
list_for_each_safe(pos, tmp, &sysc_soc->disabled_modules) {
disabled_module = list_entry(pos, struct sysc_address, node);
list_del(pos);
ddata->dev = &pdev->dev;
platform_set_drvdata(pdev, ddata);
- error = sysc_init_soc(ddata);
+ error = sysc_init_static_data(ddata);
if (error)
return error;
pm_runtime_put(&pdev->dev);
}
+ if (ddata->cfg.quirks & SYSC_QUIRK_REINIT_ON_CTX_LOST)
+ sysc_add_restored(ddata);
+
return 0;
err:
{
bus_unregister_notifier(&platform_bus_type, &sysc_nb);
platform_driver_unregister(&sysc_driver);
- sysc_cleanup_soc();
+ sysc_cleanup_static_data();
}
module_exit(sysc_exit);
projects / linux-2.6-microblaze.git / blobdiff