Initial import

1 files changed, 541 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..cbbe40377
--- /dev/null
+++ b/drivers/clk/at91/clk-pll.c
@@ -0,0 +1,541 @@
+/*
+ *  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/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/irq.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 at91_pmc *pmc;
+	unsigned int irq;
+	wait_queue_head_t wait;
+	u8 id;
+	u8 div;
+	u8 range;
+	u16 mul;
+	const struct clk_pll_layout *layout;
+	const struct clk_pll_characteristics *characteristics;
+};
+
+static irqreturn_t clk_pll_irq_handler(int irq, void *dev_id)
+{
+	struct clk_pll *pll = (struct clk_pll *)dev_id;
+
+	wake_up(&pll->wait);
+	disable_irq_nosync(pll->irq);
+
+	return IRQ_HANDLED;
+}
+
+static int clk_pll_prepare(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	struct at91_pmc *pmc = pll->pmc;
+	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;
+	u32 pllr, icpr;
+	u8 div;
+	u16 mul;
+
+	pllr = pmc_read(pmc, offset);
+	div = PLL_DIV(pllr);
+	mul = PLL_MUL(pllr, layout);
+
+	if ((pmc_read(pmc, AT91_PMC_SR) & mask) &&
+	    (div == pll->div && mul == pll->mul))
+		return 0;
+
+	if (characteristics->out)
+		out = characteristics->out[pll->range];
+	if (characteristics->icpll) {
+		icpr = pmc_read(pmc, AT91_PMC_PLLICPR) & ~PLL_ICPR_MASK(id);
+		icpr |= (characteristics->icpll[pll->range] <<
+			PLL_ICPR_SHIFT(id));
+		pmc_write(pmc, AT91_PMC_PLLICPR, icpr);
+	}
+
+	pllr &= ~layout->pllr_mask;
+	pllr |= layout->pllr_mask &
+	       (pll->div | (PLL_MAX_COUNT << PLL_COUNT_SHIFT) |
+		(out << PLL_OUT_SHIFT) |
+		((pll->mul & layout->mul_mask) << layout->mul_shift));
+	pmc_write(pmc, offset, pllr);
+
+	while (!(pmc_read(pmc, AT91_PMC_SR) & mask)) {
+		enable_irq(pll->irq);
+		wait_event(pll->wait,
+			   pmc_read(pmc, AT91_PMC_SR) & mask);
+	}
+
+	return 0;
+}
+
+static int clk_pll_is_prepared(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	struct at91_pmc *pmc = pll->pmc;
+
+	return !!(pmc_read(pmc, AT91_PMC_SR) &
+		  PLL_STATUS_MASK(pll->id));
+}
+
+static void clk_pll_unprepare(struct clk_hw *hw)
+{
+	struct clk_pll *pll = to_clk_pll(hw);
+	struct at91_pmc *pmc = pll->pmc;
+	const struct clk_pll_layout *layout = pll->layout;
+	int offset = PLL_REG(pll->id);
+	u32 tmp = pmc_read(pmc, offset) & ~(layout->pllr_mask);
+
+	pmc_write(pmc, offset, tmp);
+}
+
+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 * __init
+at91_clk_register_pll(struct at91_pmc *pmc, unsigned int irq, 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 *clk = NULL;
+	struct clk_init_data init;
+	int ret;
+	int offset = PLL_REG(id);
+	u32 tmp;
+
+	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->pmc = pmc;
+	pll->irq = irq;
+	tmp = pmc_read(pmc, offset) & layout->pllr_mask;
+	pll->div = PLL_DIV(tmp);
+	pll->mul = PLL_MUL(tmp, layout);
+	init_waitqueue_head(&pll->wait);
+	irq_set_status_flags(pll->irq, IRQ_NOAUTOEN);
+	ret = request_irq(pll->irq, clk_pll_irq_handler, IRQF_TRIGGER_HIGH,
+			  id ? "clk-pllb" : "clk-plla", pll);
+	if (ret)
+		return ERR_PTR(ret);
+
+	clk = clk_register(NULL, &pll->hw);
+	if (IS_ERR(clk))
+		kfree(pll);
+
+	return clk;
+}
+
+
+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 = kzalloc(sizeof(*output) * num_output, GFP_KERNEL);
+	if (!output)
+		goto out_free_characteristics;
+
+	if (num_cells > 2) {
+		out = kzalloc(sizeof(*out) * num_output, GFP_KERNEL);
+		if (!out)
+			goto out_free_output;
+	}
+
+	if (num_cells > 3) {
+		icpll = kzalloc(sizeof(*icpll) * num_output, 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, struct at91_pmc *pmc,
+		      const struct clk_pll_layout *layout)
+{
+	u32 id;
+	unsigned int irq;
+	struct clk *clk;
+	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);
+
+	characteristics = of_at91_clk_pll_get_characteristics(np);
+	if (!characteristics)
+		return;
+
+	irq = irq_of_parse_and_map(np, 0);
+	if (!irq)
+		return;
+
+	clk = at91_clk_register_pll(pmc, irq, name, parent_name, id, layout,
+				    characteristics);
+	if (IS_ERR(clk))
+		goto out_free_characteristics;
+
+	of_clk_add_provider(np, of_clk_src_simple_get, clk);
+	return;
+
+out_free_characteristics:
+	kfree(characteristics);
+}
+
+void __init of_at91rm9200_clk_pll_setup(struct device_node *np,
+					       struct at91_pmc *pmc)
+{
+	of_at91_clk_pll_setup(np, pmc, &at91rm9200_pll_layout);
+}
+
+void __init of_at91sam9g45_clk_pll_setup(struct device_node *np,
+						struct at91_pmc *pmc)
+{
+	of_at91_clk_pll_setup(np, pmc, &at91sam9g45_pll_layout);
+}
+
+void __init of_at91sam9g20_clk_pllb_setup(struct device_node *np,
+						 struct at91_pmc *pmc)
+{
+	of_at91_clk_pll_setup(np, pmc, &at91sam9g20_pllb_layout);
+}
+
+void __init of_sama5d3_clk_pll_setup(struct device_node *np,
+					    struct at91_pmc *pmc)
+{
+	of_at91_clk_pll_setup(np, pmc, &sama5d3_pll_layout);
+}