/* Enable a clock with no locking, enabling parent clocks as needed. */
static int local_clk_enable_nolock(unsigned id)
{
struct clk_local *clk = &soc_clk_local_tbl[id];
int rc = 0;
if (clk->type == RESET)
return -EPERM;
if (!clk->count) {
rc = local_vote_sys_vdd(clk->current_freq->sys_vdd);
if (rc)
goto err_vdd;
if (clk->parent != C(NONE)) {
rc = local_clk_enable_nolock(clk->parent);
if (rc)
goto err_par;
}
rc = local_src_enable(clk->current_freq->src);
if (rc)
goto err_src;
local_clk_enable_reg(id);
}
clk->count++;
return rc;
err_src:
if (clk->parent != C(NONE))
rc = local_clk_disable_nolock(clk->parent);
err_par:
local_unvote_sys_vdd(clk->current_freq->sys_vdd);
err_vdd:
return rc;
}
/* Enable a clock with no locking, enabling parent clocks as needed. */
static int local_clk_enable_nolock(unsigned id)
{
struct clk_local *clk = &soc_clk_local_tbl[id];
int rc = 0;
if (clk->type == RESET)
return -EPERM;
if (!clk->count) {
rc = local_vote_sys_vdd(clk->current_freq->sys_vdd);
if (rc)
goto err_vdd;
if (clk->parent != C(NONE)) {
rc = local_clk_enable_nolock(clk->parent);
if (rc)
goto err_par;
}
rc = local_src_enable(clk->current_freq->src);
if (rc)
goto err_src;
local_clk_enable_reg(id);
/*
* With remote rail control, the remote processor might modify
* the clock control register when the rail is enabled/disabled.
* Enable the rail inside the lock to protect against this.
*/
rc = soc_set_pwr_rail(id, 1);
if (rc)
goto err_pwr;
}
clk->count++;
return rc;
err_pwr:
local_clk_disable_reg(id);
err_src:
if (clk->parent != C(NONE))
rc = local_clk_disable_nolock(clk->parent);
err_par:
local_unvote_sys_vdd(clk->current_freq->sys_vdd);
err_vdd:
return rc;
}
/* Set a clock's frequency. */
static int _local_clk_set_rate(unsigned id, struct clk_freq_tbl *nf)
{
struct clk_local *clk = &soc_clk_local_tbl[id];
struct clk_freq_tbl *cf;
const int32_t *chld = clk->children;
int i, rc = 0;
unsigned long flags;
spin_lock_irqsave(&local_clock_reg_lock, flags);
/* Check if frequency is actually changed. */
cf = clk->current_freq;
if (nf == cf)
goto release_lock;
/* Disable branch if clock isn't dual-banked with a glitch-free MUX. */
if (clk->banked_mnd_masks == NULL) {
/* Disable all branches to prevent glitches. */
for (i = 0; chld && chld[i] != C(NONE); i++) {
struct clk_local *ch = &soc_clk_local_tbl[chld[i]];
/* Don't bother turning off if it is already off.
* Checking ch->count is cheaper (cache) than reading
* and writing to a register (uncached/unbuffered). */
if (ch->count)
local_clk_disable_reg(chld[i]);
}
if (clk->count)
local_clk_disable_reg(id);
}
if (clk->count) {
/* Vote for voltage and source for new freq. */
rc = local_vote_sys_vdd(nf->sys_vdd);
if (rc)
goto sys_vdd_vote_failed;
rc = local_src_enable(nf->src);
if (rc) {
local_unvote_sys_vdd(nf->sys_vdd);
goto src_enable_failed;
}
}
/* Perform clock-specific frequency switch operations. */
BUG_ON(!clk->set_rate);
clk->set_rate(clk, nf);
/* Release requirements of the old freq. */
if (clk->count) {
local_src_disable(cf->src);
local_unvote_sys_vdd(cf->sys_vdd);
}
/* Current freq must be updated before local_clk_enable_reg()
* is called to make sure the MNCNTR_EN bit is set correctly. */
clk->current_freq = nf;
src_enable_failed:
sys_vdd_vote_failed:
/* Enable any clocks that were disabled. */
if (clk->banked_mnd_masks == NULL) {
if (clk->count)
local_clk_enable_reg(id);
/* Enable only branches that were ON before. */
for (i = 0; chld && chld[i] != C(NONE); i++) {
struct clk_local *ch = &soc_clk_local_tbl[chld[i]];
if (ch->count)
local_clk_enable_reg(chld[i]);
}
}
release_lock:
spin_unlock_irqrestore(&local_clock_reg_lock, flags);
return rc;
}
