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-rw-r--r--drivers/clk/at91/clk-pll.c522
1 files changed, 522 insertions, 0 deletions
diff --git a/drivers/clk/at91/clk-pll.c b/drivers/clk/at91/clk-pll.c
new file mode 100644
index 000000000..dc7fbc796
--- /dev/null
+++ b/drivers/clk/at91/clk-pll.c
@@ -0,0 +1,522 @@
+/*
+ * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/at91_pmc.h>
+#include <linux/of.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+
+#include "pmc.h"
+
+#define PLL_STATUS_MASK(id) (1 << (1 + (id)))
+#define PLL_REG(id) (AT91_CKGR_PLLAR + ((id) * 4))
+#define PLL_DIV_MASK 0xff
+#define PLL_DIV_MAX PLL_DIV_MASK
+#define PLL_DIV(reg) ((reg) & PLL_DIV_MASK)
+#define PLL_MUL(reg, layout) (((reg) >> (layout)->mul_shift) & \
+ (layout)->mul_mask)
+#define PLL_MUL_MIN 2
+#define PLL_MUL_MASK(layout) ((layout)->mul_mask)
+#define PLL_MUL_MAX(layout) (PLL_MUL_MASK(layout) + 1)
+#define PLL_ICPR_SHIFT(id) ((id) * 16)
+#define PLL_ICPR_MASK(id) (0xffff << PLL_ICPR_SHIFT(id))
+#define PLL_MAX_COUNT 0x3f
+#define PLL_COUNT_SHIFT 8
+#define PLL_OUT_SHIFT 14
+#define PLL_MAX_ID 1
+
+struct clk_pll_characteristics {
+ struct clk_range input;
+ int num_output;
+ struct clk_range *output;
+ u16 *icpll;
+ u8 *out;
+};
+
+struct clk_pll_layout {
+ u32 pllr_mask;
+ u16 mul_mask;
+ u8 mul_shift;
+};
+
+#define to_clk_pll(hw) container_of(hw, struct clk_pll, hw)
+
+struct clk_pll {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ u8 id;
+ u8 div;
+ u8 range;
+ u16 mul;
+ const struct clk_pll_layout *layout;
+ const struct clk_pll_characteristics *characteristics;
+};
+
+static inline bool clk_pll_ready(struct regmap *regmap, int id)
+{
+ unsigned int status;
+
+ regmap_read(regmap, AT91_PMC_SR, &status);
+
+ return status & PLL_STATUS_MASK(id) ? 1 : 0;
+}
+
+static int clk_pll_prepare(struct clk_hw *hw)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+ struct regmap *regmap = pll->regmap;
+ const struct clk_pll_layout *layout = pll->layout;
+ const struct clk_pll_characteristics *characteristics =
+ pll->characteristics;
+ u8 id = pll->id;
+ u32 mask = PLL_STATUS_MASK(id);
+ int offset = PLL_REG(id);
+ u8 out = 0;
+ unsigned int pllr;
+ unsigned int status;
+ u8 div;
+ u16 mul;
+
+ regmap_read(regmap, offset, &pllr);
+ div = PLL_DIV(pllr);
+ mul = PLL_MUL(pllr, layout);
+
+ regmap_read(regmap, AT91_PMC_SR, &status);
+ if ((status & mask) &&
+ (div == pll->div && mul == pll->mul))
+ return 0;
+
+ if (characteristics->out)
+ out = characteristics->out[pll->range];
+
+ if (characteristics->icpll)
+ regmap_update_bits(regmap, AT91_PMC_PLLICPR, PLL_ICPR_MASK(id),
+ characteristics->icpll[pll->range] << PLL_ICPR_SHIFT(id));
+
+ regmap_update_bits(regmap, offset, layout->pllr_mask,
+ pll->div | (PLL_MAX_COUNT << PLL_COUNT_SHIFT) |
+ (out << PLL_OUT_SHIFT) |
+ ((pll->mul & layout->mul_mask) << layout->mul_shift));
+
+ while (!clk_pll_ready(regmap, pll->id))
+ cpu_relax();
+
+ return 0;
+}
+
+static int clk_pll_is_prepared(struct clk_hw *hw)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ return clk_pll_ready(pll->regmap, pll->id);
+}
+
+static void clk_pll_unprepare(struct clk_hw *hw)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+ unsigned int mask = pll->layout->pllr_mask;
+
+ regmap_update_bits(pll->regmap, PLL_REG(pll->id), mask, ~mask);
+}
+
+static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ if (!pll->div || !pll->mul)
+ return 0;
+
+ return (parent_rate / pll->div) * (pll->mul + 1);
+}
+
+static long clk_pll_get_best_div_mul(struct clk_pll *pll, unsigned long rate,
+ unsigned long parent_rate,
+ u32 *div, u32 *mul,
+ u32 *index) {
+ const struct clk_pll_layout *layout = pll->layout;
+ const struct clk_pll_characteristics *characteristics =
+ pll->characteristics;
+ unsigned long bestremainder = ULONG_MAX;
+ unsigned long maxdiv, mindiv, tmpdiv;
+ long bestrate = -ERANGE;
+ unsigned long bestdiv;
+ unsigned long bestmul;
+ int i = 0;
+
+ /* Check if parent_rate is a valid input rate */
+ if (parent_rate < characteristics->input.min)
+ return -ERANGE;
+
+ /*
+ * Calculate minimum divider based on the minimum multiplier, the
+ * parent_rate and the requested rate.
+ * Should always be 2 according to the input and output characteristics
+ * of the PLL blocks.
+ */
+ mindiv = (parent_rate * PLL_MUL_MIN) / rate;
+ if (!mindiv)
+ mindiv = 1;
+
+ if (parent_rate > characteristics->input.max) {
+ tmpdiv = DIV_ROUND_UP(parent_rate, characteristics->input.max);
+ if (tmpdiv > PLL_DIV_MAX)
+ return -ERANGE;
+
+ if (tmpdiv > mindiv)
+ mindiv = tmpdiv;
+ }
+
+ /*
+ * Calculate the maximum divider which is limited by PLL register
+ * layout (limited by the MUL or DIV field size).
+ */
+ maxdiv = DIV_ROUND_UP(parent_rate * PLL_MUL_MAX(layout), rate);
+ if (maxdiv > PLL_DIV_MAX)
+ maxdiv = PLL_DIV_MAX;
+
+ /*
+ * Iterate over the acceptable divider values to find the best
+ * divider/multiplier pair (the one that generates the closest
+ * rate to the requested one).
+ */
+ for (tmpdiv = mindiv; tmpdiv <= maxdiv; tmpdiv++) {
+ unsigned long remainder;
+ unsigned long tmprate;
+ unsigned long tmpmul;
+
+ /*
+ * Calculate the multiplier associated with the current
+ * divider that provide the closest rate to the requested one.
+ */
+ tmpmul = DIV_ROUND_CLOSEST(rate, parent_rate / tmpdiv);
+ tmprate = (parent_rate / tmpdiv) * tmpmul;
+ if (tmprate > rate)
+ remainder = tmprate - rate;
+ else
+ remainder = rate - tmprate;
+
+ /*
+ * Compare the remainder with the best remainder found until
+ * now and elect a new best multiplier/divider pair if the
+ * current remainder is smaller than the best one.
+ */
+ if (remainder < bestremainder) {
+ bestremainder = remainder;
+ bestdiv = tmpdiv;
+ bestmul = tmpmul;
+ bestrate = tmprate;
+ }
+
+ /*
+ * We've found a perfect match!
+ * Stop searching now and use this multiplier/divider pair.
+ */
+ if (!remainder)
+ break;
+ }
+
+ /* We haven't found any multiplier/divider pair => return -ERANGE */
+ if (bestrate < 0)
+ return bestrate;
+
+ /* Check if bestrate is a valid output rate */
+ for (i = 0; i < characteristics->num_output; i++) {
+ if (bestrate >= characteristics->output[i].min &&
+ bestrate <= characteristics->output[i].max)
+ break;
+ }
+
+ if (i >= characteristics->num_output)
+ return -ERANGE;
+
+ if (div)
+ *div = bestdiv;
+ if (mul)
+ *mul = bestmul - 1;
+ if (index)
+ *index = i;
+
+ return bestrate;
+}
+
+static long clk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+
+ return clk_pll_get_best_div_mul(pll, rate, *parent_rate,
+ NULL, NULL, NULL);
+}
+
+static int clk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_pll *pll = to_clk_pll(hw);
+ long ret;
+ u32 div;
+ u32 mul;
+ u32 index;
+
+ ret = clk_pll_get_best_div_mul(pll, rate, parent_rate,
+ &div, &mul, &index);
+ if (ret < 0)
+ return ret;
+
+ pll->range = index;
+ pll->div = div;
+ pll->mul = mul;
+
+ return 0;
+}
+
+static const struct clk_ops pll_ops = {
+ .prepare = clk_pll_prepare,
+ .unprepare = clk_pll_unprepare,
+ .is_prepared = clk_pll_is_prepared,
+ .recalc_rate = clk_pll_recalc_rate,
+ .round_rate = clk_pll_round_rate,
+ .set_rate = clk_pll_set_rate,
+};
+
+static struct clk_hw * __init
+at91_clk_register_pll(struct regmap *regmap, const char *name,
+ const char *parent_name, u8 id,
+ const struct clk_pll_layout *layout,
+ const struct clk_pll_characteristics *characteristics)
+{
+ struct clk_pll *pll;
+ struct clk_hw *hw;
+ struct clk_init_data init;
+ int offset = PLL_REG(id);
+ unsigned int pllr;
+ int ret;
+
+ if (id > PLL_MAX_ID)
+ return ERR_PTR(-EINVAL);
+
+ pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+ if (!pll)
+ return ERR_PTR(-ENOMEM);
+
+ init.name = name;
+ init.ops = &pll_ops;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+ init.flags = CLK_SET_RATE_GATE;
+
+ pll->id = id;
+ pll->hw.init = &init;
+ pll->layout = layout;
+ pll->characteristics = characteristics;
+ pll->regmap = regmap;
+ regmap_read(regmap, offset, &pllr);
+ pll->div = PLL_DIV(pllr);
+ pll->mul = PLL_MUL(pllr, layout);
+
+ hw = &pll->hw;
+ ret = clk_hw_register(NULL, &pll->hw);
+ if (ret) {
+ kfree(pll);
+ hw = ERR_PTR(ret);
+ }
+
+ return hw;
+}
+
+
+static const struct clk_pll_layout at91rm9200_pll_layout = {
+ .pllr_mask = 0x7FFFFFF,
+ .mul_shift = 16,
+ .mul_mask = 0x7FF,
+};
+
+static const struct clk_pll_layout at91sam9g45_pll_layout = {
+ .pllr_mask = 0xFFFFFF,
+ .mul_shift = 16,
+ .mul_mask = 0xFF,
+};
+
+static const struct clk_pll_layout at91sam9g20_pllb_layout = {
+ .pllr_mask = 0x3FFFFF,
+ .mul_shift = 16,
+ .mul_mask = 0x3F,
+};
+
+static const struct clk_pll_layout sama5d3_pll_layout = {
+ .pllr_mask = 0x1FFFFFF,
+ .mul_shift = 18,
+ .mul_mask = 0x7F,
+};
+
+
+static struct clk_pll_characteristics * __init
+of_at91_clk_pll_get_characteristics(struct device_node *np)
+{
+ int i;
+ int offset;
+ u32 tmp;
+ int num_output;
+ u32 num_cells;
+ struct clk_range input;
+ struct clk_range *output;
+ u8 *out = NULL;
+ u16 *icpll = NULL;
+ struct clk_pll_characteristics *characteristics;
+
+ if (of_at91_get_clk_range(np, "atmel,clk-input-range", &input))
+ return NULL;
+
+ if (of_property_read_u32(np, "#atmel,pll-clk-output-range-cells",
+ &num_cells))
+ return NULL;
+
+ if (num_cells < 2 || num_cells > 4)
+ return NULL;
+
+ if (!of_get_property(np, "atmel,pll-clk-output-ranges", &tmp))
+ return NULL;
+ num_output = tmp / (sizeof(u32) * num_cells);
+
+ characteristics = kzalloc(sizeof(*characteristics), GFP_KERNEL);
+ if (!characteristics)
+ return NULL;
+
+ output = kcalloc(num_output, sizeof(*output), GFP_KERNEL);
+ if (!output)
+ goto out_free_characteristics;
+
+ if (num_cells > 2) {
+ out = kcalloc(num_output, sizeof(*out), GFP_KERNEL);
+ if (!out)
+ goto out_free_output;
+ }
+
+ if (num_cells > 3) {
+ icpll = kcalloc(num_output, sizeof(*icpll), GFP_KERNEL);
+ if (!icpll)
+ goto out_free_output;
+ }
+
+ for (i = 0; i < num_output; i++) {
+ offset = i * num_cells;
+ if (of_property_read_u32_index(np,
+ "atmel,pll-clk-output-ranges",
+ offset, &tmp))
+ goto out_free_output;
+ output[i].min = tmp;
+ if (of_property_read_u32_index(np,
+ "atmel,pll-clk-output-ranges",
+ offset + 1, &tmp))
+ goto out_free_output;
+ output[i].max = tmp;
+
+ if (num_cells == 2)
+ continue;
+
+ if (of_property_read_u32_index(np,
+ "atmel,pll-clk-output-ranges",
+ offset + 2, &tmp))
+ goto out_free_output;
+ out[i] = tmp;
+
+ if (num_cells == 3)
+ continue;
+
+ if (of_property_read_u32_index(np,
+ "atmel,pll-clk-output-ranges",
+ offset + 3, &tmp))
+ goto out_free_output;
+ icpll[i] = tmp;
+ }
+
+ characteristics->input = input;
+ characteristics->num_output = num_output;
+ characteristics->output = output;
+ characteristics->out = out;
+ characteristics->icpll = icpll;
+ return characteristics;
+
+out_free_output:
+ kfree(icpll);
+ kfree(out);
+ kfree(output);
+out_free_characteristics:
+ kfree(characteristics);
+ return NULL;
+}
+
+static void __init
+of_at91_clk_pll_setup(struct device_node *np,
+ const struct clk_pll_layout *layout)
+{
+ u32 id;
+ struct clk_hw *hw;
+ struct regmap *regmap;
+ const char *parent_name;
+ const char *name = np->name;
+ struct clk_pll_characteristics *characteristics;
+
+ if (of_property_read_u32(np, "reg", &id))
+ return;
+
+ parent_name = of_clk_get_parent_name(np, 0);
+
+ of_property_read_string(np, "clock-output-names", &name);
+
+ regmap = syscon_node_to_regmap(of_get_parent(np));
+ if (IS_ERR(regmap))
+ return;
+
+ characteristics = of_at91_clk_pll_get_characteristics(np);
+ if (!characteristics)
+ return;
+
+ hw = at91_clk_register_pll(regmap, name, parent_name, id, layout,
+ characteristics);
+ if (IS_ERR(hw))
+ goto out_free_characteristics;
+
+ of_clk_add_hw_provider(np, of_clk_hw_simple_get, hw);
+ return;
+
+out_free_characteristics:
+ kfree(characteristics);
+}
+
+static void __init of_at91rm9200_clk_pll_setup(struct device_node *np)
+{
+ of_at91_clk_pll_setup(np, &at91rm9200_pll_layout);
+}
+CLK_OF_DECLARE(at91rm9200_clk_pll, "atmel,at91rm9200-clk-pll",
+ of_at91rm9200_clk_pll_setup);
+
+static void __init of_at91sam9g45_clk_pll_setup(struct device_node *np)
+{
+ of_at91_clk_pll_setup(np, &at91sam9g45_pll_layout);
+}
+CLK_OF_DECLARE(at91sam9g45_clk_pll, "atmel,at91sam9g45-clk-pll",
+ of_at91sam9g45_clk_pll_setup);
+
+static void __init of_at91sam9g20_clk_pllb_setup(struct device_node *np)
+{
+ of_at91_clk_pll_setup(np, &at91sam9g20_pllb_layout);
+}
+CLK_OF_DECLARE(at91sam9g20_clk_pllb, "atmel,at91sam9g20-clk-pllb",
+ of_at91sam9g20_clk_pllb_setup);
+
+static void __init of_sama5d3_clk_pll_setup(struct device_node *np)
+{
+ of_at91_clk_pll_setup(np, &sama5d3_pll_layout);
+}
+CLK_OF_DECLARE(sama5d3_clk_pll, "atmel,sama5d3-clk-pll",
+ of_sama5d3_clk_pll_setup);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-21 04:23:32 +0000