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path: root/drivers/clk/qcom/clk-hfpll.c
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-rw-r--r--drivers/clk/qcom/clk-hfpll.c249
1 files changed, 249 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-hfpll.c b/drivers/clk/qcom/clk-hfpll.c
new file mode 100644
index 0000000000..86f728dc69
--- /dev/null
+++ b/drivers/clk/qcom/clk-hfpll.c
@@ -0,0 +1,249 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018, The Linux Foundation. All rights reserved.
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/clk-provider.h>
+#include <linux/spinlock.h>
+
+#include "clk-regmap.h"
+#include "clk-hfpll.h"
+
+#define PLL_OUTCTRL BIT(0)
+#define PLL_BYPASSNL BIT(1)
+#define PLL_RESET_N BIT(2)
+
+/* Initialize a HFPLL at a given rate and enable it. */
+static void __clk_hfpll_init_once(struct clk_hw *hw)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+
+ if (likely(h->init_done))
+ return;
+
+ /* Configure PLL parameters for integer mode. */
+ if (hd->config_val)
+ regmap_write(regmap, hd->config_reg, hd->config_val);
+ regmap_write(regmap, hd->m_reg, 0);
+ regmap_write(regmap, hd->n_reg, 1);
+
+ if (hd->user_reg) {
+ u32 regval = hd->user_val;
+ unsigned long rate;
+
+ rate = clk_hw_get_rate(hw);
+
+ /* Pick the right VCO. */
+ if (hd->user_vco_mask && rate > hd->low_vco_max_rate)
+ regval |= hd->user_vco_mask;
+ regmap_write(regmap, hd->user_reg, regval);
+ }
+
+ if (hd->droop_reg)
+ regmap_write(regmap, hd->droop_reg, hd->droop_val);
+
+ h->init_done = true;
+}
+
+static void __clk_hfpll_enable(struct clk_hw *hw)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+ u32 val;
+
+ __clk_hfpll_init_once(hw);
+
+ /* Disable PLL bypass mode. */
+ regmap_update_bits(regmap, hd->mode_reg, PLL_BYPASSNL, PLL_BYPASSNL);
+
+ /*
+ * H/W requires a 5us delay between disabling the bypass and
+ * de-asserting the reset. Delay 10us just to be safe.
+ */
+ udelay(10);
+
+ /* De-assert active-low PLL reset. */
+ regmap_update_bits(regmap, hd->mode_reg, PLL_RESET_N, PLL_RESET_N);
+
+ /* Wait for PLL to lock. */
+ if (hd->status_reg)
+ /*
+ * Busy wait. Should never timeout, we add a timeout to
+ * prevent any sort of stall.
+ */
+ regmap_read_poll_timeout(regmap, hd->status_reg, val,
+ !(val & BIT(hd->lock_bit)), 0,
+ 100 * USEC_PER_MSEC);
+ else
+ udelay(60);
+
+ /* Enable PLL output. */
+ regmap_update_bits(regmap, hd->mode_reg, PLL_OUTCTRL, PLL_OUTCTRL);
+}
+
+/* Enable an already-configured HFPLL. */
+static int clk_hfpll_enable(struct clk_hw *hw)
+{
+ unsigned long flags;
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+ u32 mode;
+
+ spin_lock_irqsave(&h->lock, flags);
+ regmap_read(regmap, hd->mode_reg, &mode);
+ if (!(mode & (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL)))
+ __clk_hfpll_enable(hw);
+ spin_unlock_irqrestore(&h->lock, flags);
+
+ return 0;
+}
+
+static void __clk_hfpll_disable(struct clk_hfpll *h)
+{
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+
+ /*
+ * Disable the PLL output, disable test mode, enable the bypass mode,
+ * and assert the reset.
+ */
+ regmap_update_bits(regmap, hd->mode_reg,
+ PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL, 0);
+}
+
+static void clk_hfpll_disable(struct clk_hw *hw)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ unsigned long flags;
+
+ spin_lock_irqsave(&h->lock, flags);
+ __clk_hfpll_disable(h);
+ spin_unlock_irqrestore(&h->lock, flags);
+}
+
+static int clk_hfpll_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ unsigned long rrate;
+
+ req->rate = clamp(req->rate, hd->min_rate, hd->max_rate);
+
+ rrate = DIV_ROUND_UP(req->rate, req->best_parent_rate) * req->best_parent_rate;
+ if (rrate > hd->max_rate)
+ rrate -= req->best_parent_rate;
+
+ req->rate = rrate;
+ return 0;
+}
+
+/*
+ * For optimization reasons, assumes no downstream clocks are actively using
+ * it.
+ */
+static int clk_hfpll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+ unsigned long flags;
+ u32 l_val, val;
+ bool enabled;
+
+ l_val = rate / parent_rate;
+
+ spin_lock_irqsave(&h->lock, flags);
+
+ enabled = __clk_is_enabled(hw->clk);
+ if (enabled)
+ __clk_hfpll_disable(h);
+
+ /* Pick the right VCO. */
+ if (hd->user_reg && hd->user_vco_mask) {
+ regmap_read(regmap, hd->user_reg, &val);
+ if (rate <= hd->low_vco_max_rate)
+ val &= ~hd->user_vco_mask;
+ else
+ val |= hd->user_vco_mask;
+ regmap_write(regmap, hd->user_reg, val);
+ }
+
+ regmap_write(regmap, hd->l_reg, l_val);
+
+ if (enabled)
+ __clk_hfpll_enable(hw);
+
+ spin_unlock_irqrestore(&h->lock, flags);
+
+ return 0;
+}
+
+static unsigned long clk_hfpll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+ u32 l_val;
+
+ regmap_read(regmap, hd->l_reg, &l_val);
+
+ return l_val * parent_rate;
+}
+
+static int clk_hfpll_init(struct clk_hw *hw)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+ u32 mode, status;
+
+ regmap_read(regmap, hd->mode_reg, &mode);
+ if (mode != (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL)) {
+ __clk_hfpll_init_once(hw);
+ return 0;
+ }
+
+ if (hd->status_reg) {
+ regmap_read(regmap, hd->status_reg, &status);
+ if (!(status & BIT(hd->lock_bit))) {
+ WARN(1, "HFPLL %s is ON, but not locked!\n",
+ __clk_get_name(hw->clk));
+ clk_hfpll_disable(hw);
+ __clk_hfpll_init_once(hw);
+ }
+ }
+
+ return 0;
+}
+
+static int hfpll_is_enabled(struct clk_hw *hw)
+{
+ struct clk_hfpll *h = to_clk_hfpll(hw);
+ struct hfpll_data const *hd = h->d;
+ struct regmap *regmap = h->clkr.regmap;
+ u32 mode;
+
+ regmap_read(regmap, hd->mode_reg, &mode);
+ mode &= 0x7;
+ return mode == (PLL_BYPASSNL | PLL_RESET_N | PLL_OUTCTRL);
+}
+
+const struct clk_ops clk_ops_hfpll = {
+ .enable = clk_hfpll_enable,
+ .disable = clk_hfpll_disable,
+ .is_enabled = hfpll_is_enabled,
+ .determine_rate = clk_hfpll_determine_rate,
+ .set_rate = clk_hfpll_set_rate,
+ .recalc_rate = clk_hfpll_recalc_rate,
+ .init = clk_hfpll_init,
+};
+EXPORT_SYMBOL_GPL(clk_ops_hfpll);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 13:38:22 +0000