[PATCH V4 08/12] clk: sprd: add adjustable pll support
Chunyan Zhang
chunyan.zhang at spreadtrum.com
Thu Nov 9 22:36:03 PST 2017
Introduced a common adjustable pll clock driver for Spreadtrum SoCs.
Signed-off-by: Chunyan Zhang <chunyan.zhang at spreadtrum.com>
---
drivers/clk/sprd/Makefile | 1 +
drivers/clk/sprd/pll.c | 268 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/clk/sprd/pll.h | 110 +++++++++++++++++++
3 files changed, 379 insertions(+)
create mode 100644 drivers/clk/sprd/pll.c
create mode 100644 drivers/clk/sprd/pll.h
diff --git a/drivers/clk/sprd/Makefile b/drivers/clk/sprd/Makefile
index 2262e76..d693969 100644
--- a/drivers/clk/sprd/Makefile
+++ b/drivers/clk/sprd/Makefile
@@ -5,3 +5,4 @@ clk-sprd-y += gate.o
clk-sprd-y += mux.o
clk-sprd-y += div.o
clk-sprd-y += composite.o
+clk-sprd-y += pll.o
diff --git a/drivers/clk/sprd/pll.c b/drivers/clk/sprd/pll.c
new file mode 100644
index 0000000..1fd8d32
--- /dev/null
+++ b/drivers/clk/sprd/pll.c
@@ -0,0 +1,268 @@
+/*
+ * Spreadtrum pll clock driver
+ *
+ * Copyright (C) 2015~2017 Spreadtrum, Inc.
+ * Author: Chunyan Zhang <chunyan.zhang at spreadtrum.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "pll.h"
+
+#define CLK_PLL_1M 1000000
+#define CLK_PLL_10M (CLK_PLL_1M * 10)
+
+#define pindex(pll, member) \
+ (pll->factors[member].shift / (8 * sizeof(pll->regs_num)))
+
+#define pshift(pll, member) \
+ (pll->factors[member].shift % (8 * sizeof(pll->regs_num)))
+
+#define pwidth(pll, member) \
+ pll->factors[member].width
+
+#define pmask(pll, member) \
+ ((pwidth(pll, member)) ? \
+ GENMASK(pwidth(pll, member) + pshift(pll, member) - 1, \
+ pshift(pll, member)) : 0)
+
+#define pinternal(pll, cfg, member) \
+ (cfg[pindex(pll, member)] & pmask(pll, member))
+
+#define pinternal_val(pll, cfg, member) \
+ (pinternal(pll, cfg, member) >> pshift(pll, member))
+
+static inline unsigned int
+sprd_pll_read(const struct sprd_pll *pll, u8 index)
+{
+ const struct sprd_clk_common *common = &pll->common;
+ unsigned int val = 0;
+
+ if (WARN_ON(index >= pll->regs_num))
+ return 0;
+
+ sprd_regmap_read(common->regmap, common->reg + index * 4, &val);
+
+ return val;
+}
+
+static inline void
+sprd_pll_write(const struct sprd_pll *pll, u8 index,
+ u32 msk, u32 val)
+{
+ const struct sprd_clk_common *common = &pll->common;
+ unsigned int offset, reg;
+ int ret = 0;
+
+ if (WARN_ON(index >= pll->regs_num))
+ return;
+
+ offset = common->reg + index * 4;
+ ret = sprd_regmap_read(common->regmap, offset, ®);
+ if (!ret)
+ sprd_regmap_write(common->regmap, offset, (reg & ~msk) | val);
+}
+
+static unsigned long pll_get_refin(const struct sprd_pll *pll)
+{
+ u32 shift, mask, index, refin_id = 3;
+ const unsigned long refin[4] = { 2, 4, 13, 26 };
+
+ if (pwidth(pll, PLL_REFIN)) {
+ index = pindex(pll, PLL_REFIN);
+ shift = pshift(pll, PLL_REFIN);
+ mask = pmask(pll, PLL_REFIN);
+ refin_id = (sprd_pll_read(pll, index) & mask) >> shift;
+ if (refin_id > 3)
+ refin_id = 3;
+ }
+
+ return refin[refin_id];
+}
+
+static u32 pll_get_ibias(u64 rate, const u64 *table)
+{
+ u32 i, num = table[0];
+
+ for (i = 1; i < num + 1; i++)
+ if (rate <= table[i])
+ break;
+
+ return (i == num + 1) ? num : i;
+}
+
+static unsigned long _sprd_pll_recalc_rate(const struct sprd_pll *pll,
+ unsigned long parent_rate)
+{
+ u32 *cfg;
+ u32 i, mask, regs_num = pll->regs_num;
+ unsigned long rate, nint, kint = 0;
+ u64 refin;
+ u16 k1, k2;
+
+ cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL);
+ if (!cfg)
+ return -ENOMEM;
+
+ for (i = 0; i < regs_num; i++)
+ cfg[i] = sprd_pll_read(pll, i);
+
+ refin = pll_get_refin(pll);
+
+ if (pinternal(pll, cfg, PLL_PREDIV))
+ refin = refin * 2;
+
+ if (pwidth(pll, PLL_POSTDIV) &&
+ ((pll->fflag == 1 && pinternal(pll, cfg, PLL_POSTDIV)) ||
+ (!pll->fflag && !pinternal(pll, cfg, PLL_POSTDIV))))
+ refin = refin / 2;
+
+ if (!pinternal(pll, cfg, PLL_DIV_S)) {
+ rate = refin * pinternal_val(pll, cfg, PLL_N) * CLK_PLL_10M;
+ } else {
+ nint = pinternal_val(pll, cfg, PLL_NINT);
+ if (pinternal(pll, cfg, PLL_SDM_EN))
+ kint = pinternal_val(pll, cfg, PLL_KINT);
+
+ mask = pmask(pll, PLL_KINT);
+
+ k1 = pll->k1;
+ k2 = pll->k2;
+ rate = DIV_ROUND_CLOSEST_ULL(refin * kint * k1,
+ ((mask >> __ffs(mask)) + 1)) *
+ k2 + refin * nint * CLK_PLL_1M;
+ }
+
+ return rate;
+}
+
+#define SPRD_PLL_WRITE_CHECK(pll, i, mask, val) \
+ (((sprd_pll_read(pll, i) & mask) == val) ? 0 : (-EFAULT))
+
+static int _sprd_pll_set_rate(const struct sprd_pll *pll,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct reg_cfg *cfg;
+ int ret = 0;
+ u32 mask, shift, width, ibias_val, index;
+ u32 regs_num = pll->regs_num, i = 0;
+ unsigned long kint, nint;
+ u64 tmp, refin, fvco = rate;
+
+ cfg = kcalloc(regs_num, sizeof(*cfg), GFP_KERNEL);
+ if (!cfg)
+ return -ENOMEM;
+
+ refin = pll_get_refin(pll);
+
+ mask = pmask(pll, PLL_PREDIV);
+ index = pindex(pll, PLL_PREDIV);
+ width = pwidth(pll, PLL_PREDIV);
+ if (width && (sprd_pll_read(pll, index) & mask))
+ refin = refin * 2;
+
+ mask = pmask(pll, PLL_POSTDIV);
+ index = pindex(pll, PLL_POSTDIV);
+ width = pwidth(pll, PLL_POSTDIV);
+ cfg[index].msk = mask;
+ if (width && ((pll->fflag == 1 && fvco <= pll->fvco) ||
+ (pll->fflag == 0 && fvco > pll->fvco)))
+ cfg[index].val |= mask;
+
+ if (width && fvco <= pll->fvco)
+ fvco = fvco * 2;
+
+ mask = pmask(pll, PLL_DIV_S);
+ index = pindex(pll, PLL_DIV_S);
+ cfg[index].val |= mask;
+ cfg[index].msk |= mask;
+
+ mask = pmask(pll, PLL_SDM_EN);
+ index = pindex(pll, PLL_SDM_EN);
+ cfg[index].val |= mask;
+ cfg[index].msk |= mask;
+
+ nint = do_div(fvco, refin * CLK_PLL_1M);
+ mask = pmask(pll, PLL_NINT);
+ index = pindex(pll, PLL_NINT);
+ shift = pshift(pll, PLL_NINT);
+ cfg[index].val |= (nint << shift) & mask;
+ cfg[index].msk |= mask;
+
+ mask = pmask(pll, PLL_KINT);
+ index = pindex(pll, PLL_KINT);
+ width = pwidth(pll, PLL_KINT);
+ shift = pshift(pll, PLL_KINT);
+ tmp = fvco - refin * nint * CLK_PLL_1M;
+ tmp = do_div(tmp, 10000) * ((mask >> shift) + 1);
+ kint = DIV_ROUND_CLOSEST_ULL(tmp, refin * 100);
+ cfg[index].val |= (kint << shift) & mask;
+ cfg[index].msk |= mask;
+
+ ibias_val = pll_get_ibias(fvco, pll->itable);
+
+ mask = pmask(pll, PLL_IBIAS);
+ index = pindex(pll, PLL_IBIAS);
+ shift = pshift(pll, PLL_IBIAS);
+ cfg[index].val |= ibias_val << shift & mask;
+ cfg[index].msk |= mask;
+
+ for (i = 0; i < regs_num; i++) {
+ if (cfg[i].msk) {
+ sprd_pll_write(pll, i, cfg[i].msk, cfg[i].val);
+ ret |= SPRD_PLL_WRITE_CHECK(pll, i, cfg[i].msk,
+ cfg[i].val);
+ }
+ }
+
+ if (!ret)
+ udelay(pll->udelay);
+
+ return ret;
+}
+
+static unsigned long sprd_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct sprd_pll *pll = hw_to_sprd_pll(hw);
+
+ return _sprd_pll_recalc_rate(pll, parent_rate);
+}
+
+static int sprd_pll_set_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct sprd_pll *pll = hw_to_sprd_pll(hw);
+
+ return _sprd_pll_set_rate(pll, rate, parent_rate);
+}
+
+static int sprd_pll_clk_prepare(struct clk_hw *hw)
+{
+ struct sprd_pll *pll = hw_to_sprd_pll(hw);
+
+ udelay(pll->udelay);
+
+ return 0;
+}
+
+static long sprd_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *prate)
+{
+ return rate;
+}
+
+const struct clk_ops sprd_pll_ops = {
+ .prepare = sprd_pll_clk_prepare,
+ .recalc_rate = sprd_pll_recalc_rate,
+ .round_rate = sprd_pll_round_rate,
+ .set_rate = sprd_pll_set_rate,
+};
+EXPORT_SYMBOL_GPL(sprd_pll_ops);
diff --git a/drivers/clk/sprd/pll.h b/drivers/clk/sprd/pll.h
new file mode 100644
index 0000000..a25b003
--- /dev/null
+++ b/drivers/clk/sprd/pll.h
@@ -0,0 +1,110 @@
+/*
+ * Spreadtrum clock pll configurations
+ *
+ * Copyright (C) 2015~2017 Spreadtrum, Inc.
+ * Author: Chunyan Zhang <chunyan.zhang at spreadtrum.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef _SPRD_PLL_H_
+#define _SPRD_PLL_H_
+
+#include "common.h"
+
+struct reg_cfg {
+ u32 val;
+ u32 msk;
+};
+
+struct clk_bit_field {
+ u8 shift;
+ u8 width;
+};
+
+enum {
+ PLL_LOCK_DONE,
+ PLL_DIV_S,
+ PLL_MOD_EN,
+ PLL_SDM_EN,
+ PLL_REFIN,
+ PLL_IBIAS,
+ PLL_N,
+ PLL_NINT,
+ PLL_KINT,
+ PLL_PREDIV,
+ PLL_POSTDIV,
+
+ PLL_FACT_MAX
+};
+
+/*
+ * struct sprd_pll - definition of adjustable pll clock
+ *
+ * @reg: registers used to set the configuration of pll clock,
+ * reg[0] shows how many registers this pll clock uses.
+ * @itable: pll ibias table, itable[0] means how many items this
+ * table includes
+ * @udelay delay time after setting rate
+ * @factors used to calculate the pll clock rate
+ * @fvco: fvco threshold rate
+ * @fflag: fvco flag
+ */
+struct sprd_pll {
+ u32 regs_num;
+ const u64 *itable;
+ const struct clk_bit_field *factors;
+ u16 udelay;
+ u16 k1;
+ u16 k2;
+ u16 fflag;
+ u64 fvco;
+
+ struct sprd_clk_common common;
+};
+
+#define SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg, \
+ _regs_num, _itable, _factors, \
+ _udelay, _k1, _k2, _fflag, _fvco) \
+ struct sprd_pll _struct = { \
+ .regs_num = _regs_num, \
+ .itable = _itable, \
+ .factors = _factors, \
+ .udelay = _udelay, \
+ .k1 = _k1, \
+ .k2 = _k2, \
+ .fflag = _fflag, \
+ .fvco = _fvco, \
+ .common = { \
+ .regmap = NULL, \
+ .reg = _reg, \
+ .hw.init = CLK_HW_INIT(_name, \
+ _parent, \
+ &sprd_pll_ops, \
+ 0), \
+ }, \
+ }
+
+#define SPRD_PLL_WITH_ITABLE_K(_struct, _name, _parent, _reg, \
+ _regs_num, _itable, _factors, \
+ _udelay, _k1, _k2) \
+ SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg, \
+ _regs_num, _itable, _factors, \
+ _udelay, _k1, _k2, 0, 0)
+
+#define SPRD_PLL_WITH_ITABLE_1K(_struct, _name, _parent, _reg, \
+ _regs_num, _itable, _factors, _udelay) \
+ SPRD_PLL_WITH_ITABLE_K_FVCO(_struct, _name, _parent, _reg, \
+ _regs_num, _itable, _factors, \
+ _udelay, 1000, 1000, 0, 0)
+
+static inline struct sprd_pll *hw_to_sprd_pll(struct clk_hw *hw)
+{
+ struct sprd_clk_common *common = hw_to_sprd_clk_common(hw);
+
+ return container_of(common, struct sprd_pll, common);
+}
+
+extern const struct clk_ops sprd_pll_ops;
+
+#endif /* _SPRD_PLL_H_ */
--
2.7.4
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