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-rw-r--r--drivers/clk/mmp/clk-pll.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/clk/mmp/clk-pll.c b/drivers/clk/mmp/clk-pll.c
new file mode 100644
index 000000000..962014cfd
--- /dev/null
+++ b/drivers/clk/mmp/clk-pll.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MMP PLL clock rate calculation
+ *
+ * Copyright (C) 2020 Lubomir Rintel <lkundrak@v3.sk>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include "clk.h"
+
+#define to_clk_mmp_pll(hw) container_of(hw, struct mmp_clk_pll, hw)
+
+struct mmp_clk_pll {
+ struct clk_hw hw;
+ unsigned long default_rate;
+ void __iomem *enable_reg;
+ u32 enable;
+ void __iomem *reg;
+ u8 shift;
+
+ unsigned long input_rate;
+ void __iomem *postdiv_reg;
+ u8 postdiv_shift;
+};
+
+static int mmp_clk_pll_is_enabled(struct clk_hw *hw)
+{
+ struct mmp_clk_pll *pll = to_clk_mmp_pll(hw);
+ u32 val;
+
+ val = readl_relaxed(pll->enable_reg);
+ if ((val & pll->enable) == pll->enable)
+ return 1;
+
+ /* Some PLLs, if not software controlled, output default clock. */
+ if (pll->default_rate > 0)
+ return 1;
+
+ return 0;
+}
+
+static unsigned long mmp_clk_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct mmp_clk_pll *pll = to_clk_mmp_pll(hw);
+ u32 fbdiv, refdiv, postdiv;
+ u64 rate;
+ u32 val;
+
+ val = readl_relaxed(pll->enable_reg);
+ if ((val & pll->enable) != pll->enable)
+ return pll->default_rate;
+
+ if (pll->reg) {
+ val = readl_relaxed(pll->reg);
+ fbdiv = (val >> pll->shift) & 0x1ff;
+ refdiv = (val >> (pll->shift + 9)) & 0x1f;
+ } else {
+ fbdiv = 2;
+ refdiv = 1;
+ }
+
+ if (pll->postdiv_reg) {
+ /* MMP3 clock rate calculation */
+ static const u8 postdivs[] = {2, 3, 4, 5, 6, 8, 10, 12, 16};
+
+ val = readl_relaxed(pll->postdiv_reg);
+ postdiv = (val >> pll->postdiv_shift) & 0x7;
+
+ rate = pll->input_rate;
+ rate *= 2 * fbdiv;
+ do_div(rate, refdiv);
+ do_div(rate, postdivs[postdiv]);
+ } else {
+ /* MMP2 clock rate calculation */
+ if (refdiv == 3) {
+ rate = 19200000;
+ } else if (refdiv == 4) {
+ rate = 26000000;
+ } else {
+ pr_err("bad refdiv: %d (0x%08x)\n", refdiv, val);
+ return 0;
+ }
+
+ rate *= fbdiv + 2;
+ do_div(rate, refdiv + 2);
+ }
+
+ return (unsigned long)rate;
+}
+
+static const struct clk_ops mmp_clk_pll_ops = {
+ .is_enabled = mmp_clk_pll_is_enabled,
+ .recalc_rate = mmp_clk_pll_recalc_rate,
+};
+
+static struct clk *mmp_clk_register_pll(char *name,
+ unsigned long default_rate,
+ void __iomem *enable_reg, u32 enable,
+ void __iomem *reg, u8 shift,
+ unsigned long input_rate,
+ void __iomem *postdiv_reg, u8 postdiv_shift)
+{
+ struct mmp_clk_pll *pll;
+ struct clk *clk;
+ struct clk_init_data init;
+
+ pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+ if (!pll)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &mmp_clk_pll_ops;
+ init.flags = 0;
+ init.parent_names = NULL;
+ init.num_parents = 0;
+
+ pll->default_rate = default_rate;
+ pll->enable_reg = enable_reg;
+ pll->enable = enable;
+ pll->reg = reg;
+ pll->shift = shift;
+
+ pll->input_rate = input_rate;
+ pll->postdiv_reg = postdiv_reg;
+ pll->postdiv_shift = postdiv_shift;
+
+ pll->hw.init = &init;
+
+ clk = clk_register(NULL, &pll->hw);
+
+ if (IS_ERR(clk))
+ kfree(pll);
+
+ return clk;
+}
+
+void mmp_register_pll_clks(struct mmp_clk_unit *unit,
+ struct mmp_param_pll_clk *clks,
+ void __iomem *base, int size)
+{
+ struct clk *clk;
+ int i;
+
+ for (i = 0; i < size; i++) {
+ void __iomem *reg = NULL;
+
+ if (clks[i].offset)
+ reg = base + clks[i].offset;
+
+ clk = mmp_clk_register_pll(clks[i].name,
+ clks[i].default_rate,
+ base + clks[i].enable_offset,
+ clks[i].enable,
+ reg, clks[i].shift,
+ clks[i].input_rate,
+ base + clks[i].postdiv_offset,
+ clks[i].postdiv_shift);
+ if (IS_ERR(clk)) {
+ pr_err("%s: failed to register clock %s\n",
+ __func__, clks[i].name);
+ continue;
+ }
+ if (clks[i].id)
+ unit->clk_table[clks[i].id] = clk;
+ }
+}