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path: root/drivers/clk/meson/clk-pll.c
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Diffstat (limited to 'drivers/clk/meson/clk-pll.c')
-rw-r--r--drivers/clk/meson/clk-pll.c53
1 files changed, 51 insertions, 2 deletions
diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index 4adc1e89212c..01341553f50b 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -116,6 +116,30 @@ static const struct pll_rate_table *meson_clk_get_pll_settings(struct meson_clk_
return NULL;
}
+/* Specific wait loop for GXL/GXM GP0 PLL */
+static int meson_clk_pll_wait_lock_reset(struct meson_clk_pll *pll,
+ struct parm *p_n)
+{
+ int delay = 100;
+ u32 reg;
+
+ while (delay > 0) {
+ reg = readl(pll->base + p_n->reg_off);
+ writel(reg | MESON_PLL_RESET, pll->base + p_n->reg_off);
+ udelay(10);
+ writel(reg & ~MESON_PLL_RESET, pll->base + p_n->reg_off);
+
+ /* This delay comes from AMLogic tree clk-gp0-gxl driver */
+ mdelay(1);
+
+ reg = readl(pll->base + p_n->reg_off);
+ if (reg & MESON_PLL_LOCK)
+ return 0;
+ delay--;
+ }
+ return -ETIMEDOUT;
+}
+
static int meson_clk_pll_wait_lock(struct meson_clk_pll *pll,
struct parm *p_n)
{
@@ -132,6 +156,15 @@ static int meson_clk_pll_wait_lock(struct meson_clk_pll *pll,
return -ETIMEDOUT;
}
+static void meson_clk_pll_init_params(struct meson_clk_pll *pll)
+{
+ int i;
+
+ for (i = 0 ; i < pll->params.params_count ; ++i)
+ writel(pll->params.params_table[i].value,
+ pll->base + pll->params.params_table[i].reg_off);
+}
+
static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
@@ -151,10 +184,16 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
if (!rate_set)
return -EINVAL;
+ /* Initialize the PLL in a clean state if specified */
+ if (pll->params.params_count)
+ meson_clk_pll_init_params(pll);
+
/* PLL reset */
p = &pll->n;
reg = readl(pll->base + p->reg_off);
- writel(reg | MESON_PLL_RESET, pll->base + p->reg_off);
+ /* If no_init_reset is provided, avoid resetting at this point */
+ if (!pll->params.no_init_reset)
+ writel(reg | MESON_PLL_RESET, pll->base + p->reg_off);
reg = PARM_SET(p->width, p->shift, reg, rate_set->n);
writel(reg, pll->base + p->reg_off);
@@ -184,7 +223,17 @@ static int meson_clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
}
p = &pll->n;
- ret = meson_clk_pll_wait_lock(pll, p);
+ /* If clear_reset_for_lock is provided, remove the reset bit here */
+ if (pll->params.clear_reset_for_lock) {
+ reg = readl(pll->base + p->reg_off);
+ writel(reg & ~MESON_PLL_RESET, pll->base + p->reg_off);
+ }
+
+ /* If reset_lock_loop, use a special loop including resetting */
+ if (pll->params.reset_lock_loop)
+ ret = meson_clk_pll_wait_lock_reset(pll, p);
+ else
+ ret = meson_clk_pll_wait_lock(pll, p);
if (ret) {
pr_warn("%s: pll did not lock, trying to restore old rate %lu\n",
__func__, old_rate);