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-rw-r--r--drivers/clk/imx/clk-pfdv2.c242
1 files changed, 242 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk-pfdv2.c b/drivers/clk/imx/clk-pfdv2.c
new file mode 100644
index 000000000..6ca53a960
--- /dev/null
+++ b/drivers/clk/imx/clk-pfdv2.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2016 Freescale Semiconductor, Inc.
+ * Copyright 2017~2018 NXP
+ *
+ * Author: Dong Aisheng <aisheng.dong@nxp.com>
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/slab.h>
+
+#include "clk.h"
+
+/**
+ * struct clk_pfdv2 - IMX PFD clock
+ * @hw: clock source
+ * @reg: PFD register address
+ * @gate_bit: Gate bit offset
+ * @vld_bit: Valid bit offset
+ * @frac_off: PLL Fractional Divider offset
+ */
+
+struct clk_pfdv2 {
+ struct clk_hw hw;
+ void __iomem *reg;
+ u8 gate_bit;
+ u8 vld_bit;
+ u8 frac_off;
+};
+
+#define to_clk_pfdv2(_hw) container_of(_hw, struct clk_pfdv2, hw)
+
+#define CLK_PFDV2_FRAC_MASK 0x3f
+
+#define LOCK_TIMEOUT_US USEC_PER_MSEC
+
+static DEFINE_SPINLOCK(pfd_lock);
+
+static int clk_pfdv2_wait(struct clk_pfdv2 *pfd)
+{
+ u32 val;
+
+ return readl_poll_timeout(pfd->reg, val, val & (1 << pfd->vld_bit),
+ 0, LOCK_TIMEOUT_US);
+}
+
+static int clk_pfdv2_enable(struct clk_hw *hw)
+{
+ struct clk_pfdv2 *pfd = to_clk_pfdv2(hw);
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&pfd_lock, flags);
+ val = readl_relaxed(pfd->reg);
+ val &= ~(1 << pfd->gate_bit);
+ writel_relaxed(val, pfd->reg);
+ spin_unlock_irqrestore(&pfd_lock, flags);
+
+ return clk_pfdv2_wait(pfd);
+}
+
+static void clk_pfdv2_disable(struct clk_hw *hw)
+{
+ struct clk_pfdv2 *pfd = to_clk_pfdv2(hw);
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&pfd_lock, flags);
+ val = readl_relaxed(pfd->reg);
+ val |= (1 << pfd->gate_bit);
+ writel_relaxed(val, pfd->reg);
+ spin_unlock_irqrestore(&pfd_lock, flags);
+}
+
+static unsigned long clk_pfdv2_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_pfdv2 *pfd = to_clk_pfdv2(hw);
+ u64 tmp = parent_rate;
+ u8 frac;
+
+ frac = (readl_relaxed(pfd->reg) >> pfd->frac_off)
+ & CLK_PFDV2_FRAC_MASK;
+
+ if (!frac) {
+ pr_debug("clk_pfdv2: %s invalid pfd frac value 0\n",
+ clk_hw_get_name(hw));
+ return 0;
+ }
+
+ tmp *= 18;
+ do_div(tmp, frac);
+
+ return tmp;
+}
+
+static int clk_pfdv2_determine_rate(struct clk_hw *hw,
+ struct clk_rate_request *req)
+{
+ unsigned long parent_rates[] = {
+ 480000000,
+ 528000000,
+ req->best_parent_rate
+ };
+ unsigned long best_rate = -1UL, rate = req->rate;
+ unsigned long best_parent_rate = req->best_parent_rate;
+ u64 tmp;
+ u8 frac;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(parent_rates); i++) {
+ tmp = parent_rates[i];
+ tmp = tmp * 18 + rate / 2;
+ do_div(tmp, rate);
+ frac = tmp;
+
+ if (frac < 12)
+ frac = 12;
+ else if (frac > 35)
+ frac = 35;
+
+ tmp = parent_rates[i];
+ tmp *= 18;
+ do_div(tmp, frac);
+
+ if (abs(tmp - req->rate) < abs(best_rate - req->rate)) {
+ best_rate = tmp;
+ best_parent_rate = parent_rates[i];
+ }
+ }
+
+ req->best_parent_rate = best_parent_rate;
+ req->rate = best_rate;
+
+ return 0;
+}
+
+static int clk_pfdv2_is_enabled(struct clk_hw *hw)
+{
+ struct clk_pfdv2 *pfd = to_clk_pfdv2(hw);
+
+ if (readl_relaxed(pfd->reg) & (1 << pfd->gate_bit))
+ return 0;
+
+ return 1;
+}
+
+static int clk_pfdv2_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_pfdv2 *pfd = to_clk_pfdv2(hw);
+ unsigned long flags;
+ u64 tmp = parent_rate;
+ u32 val;
+ u8 frac;
+
+ if (!rate)
+ return -EINVAL;
+
+ /*
+ * PFD can NOT change rate without gating.
+ * as the PFDs may enabled in HW by default but no
+ * consumer used it, the enable count is '0', so the
+ * 'SET_RATE_GATE' can NOT help on blocking the set_rate
+ * ops especially for 'assigned-clock-xxx'. In order
+ * to simplify the case, just disable the PFD if it is
+ * enabled in HW but not in SW.
+ */
+ if (clk_pfdv2_is_enabled(hw))
+ clk_pfdv2_disable(hw);
+
+ tmp = tmp * 18 + rate / 2;
+ do_div(tmp, rate);
+ frac = tmp;
+ if (frac < 12)
+ frac = 12;
+ else if (frac > 35)
+ frac = 35;
+
+ spin_lock_irqsave(&pfd_lock, flags);
+ val = readl_relaxed(pfd->reg);
+ val &= ~(CLK_PFDV2_FRAC_MASK << pfd->frac_off);
+ val |= frac << pfd->frac_off;
+ writel_relaxed(val, pfd->reg);
+ spin_unlock_irqrestore(&pfd_lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops clk_pfdv2_ops = {
+ .enable = clk_pfdv2_enable,
+ .disable = clk_pfdv2_disable,
+ .recalc_rate = clk_pfdv2_recalc_rate,
+ .determine_rate = clk_pfdv2_determine_rate,
+ .set_rate = clk_pfdv2_set_rate,
+ .is_enabled = clk_pfdv2_is_enabled,
+};
+
+struct clk_hw *imx_clk_hw_pfdv2(enum imx_pfdv2_type type, const char *name,
+ const char *parent_name, void __iomem *reg, u8 idx)
+{
+ struct clk_init_data init;
+ struct clk_pfdv2 *pfd;
+ struct clk_hw *hw;
+ int ret;
+
+ WARN_ON(idx > 3);
+
+ pfd = kzalloc(sizeof(*pfd), GFP_KERNEL);
+ if (!pfd)
+ return ERR_PTR(-ENOMEM);
+
+ pfd->reg = reg;
+ pfd->gate_bit = (idx + 1) * 8 - 1;
+ pfd->vld_bit = pfd->gate_bit - 1;
+ pfd->frac_off = idx * 8;
+
+ init.name = name;
+ init.ops = &clk_pfdv2_ops;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+ if (type == IMX_PFDV2_IMX7ULP)
+ init.flags = CLK_SET_RATE_GATE | CLK_SET_RATE_PARENT;
+ else
+ init.flags = CLK_SET_RATE_GATE;
+
+ pfd->hw.init = &init;
+
+ hw = &pfd->hw;
+ ret = clk_hw_register(NULL, hw);
+ if (ret) {
+ kfree(pfd);
+ hw = ERR_PTR(ret);
+ }
+
+ return hw;
+}
+EXPORT_SYMBOL_GPL(imx_clk_hw_pfdv2);