1 files changed, 513 insertions, 0 deletions
diff --git a/arch/arm/cpu/armv7/bcm281xx/clk-core.c b/arch/arm/cpu/armv7/bcm281xx/clk-core.c
new file mode 100644
index 0000000000..d4425835a1
--- /dev/null
+++ b/arch/arm/cpu/armv7/bcm281xx/clk-core.c
@@ -0,0 +1,513 @@
+/*
+ * Copyright 2013 Broadcom Corporation.
+ *
+ * SPDX-License-Identifier:      GPL-2.0+
+ */
+
+/*
+ *
+ * bcm281xx architecture clock framework
+ *
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include <bitfield.h>
+#include <asm/arch/sysmap.h>
+#include <asm/kona-common/clk.h>
+#include "clk-core.h"
+
+#define CLK_WR_ACCESS_PASSWORD	0x00a5a501
+#define WR_ACCESS_OFFSET	0	/* common to all clock blocks */
+#define POLICY_CTL_GO		1	/* Load and refresh policy masks */
+#define POLICY_CTL_GO_ATL	4	/* Active Load */
+
+/* Helper function */
+int clk_get_and_enable(char *clkstr)
+{
+	int ret = 0;
+	struct clk *c;
+
+	debug("%s: %s\n", __func__, clkstr);
+
+	c = clk_get(clkstr);
+	if (c) {
+		ret = clk_enable(c);
+		if (ret)
+			return ret;
+	} else {
+		printf("%s: Couldn't find %s\n", __func__, clkstr);
+		return -EINVAL;
+	}
+	return ret;
+}
+
+/*
+ * Poll a register in a CCU's address space, returning when the
+ * specified bit in that register's value is set (or clear).  Delay
+ * a microsecond after each read of the register.  Returns true if
+ * successful, or false if we gave up trying.
+ *
+ * Caller must ensure the CCU lock is held.
+ */
+#define CLK_GATE_DELAY_USEC 2000
+static inline int wait_bit(void *base, u32 offset, u32 bit, bool want)
+{
+	unsigned int tries;
+	u32 bit_mask = 1 << bit;
+
+	for (tries = 0; tries < CLK_GATE_DELAY_USEC; tries++) {
+		u32 val;
+		bool bit_val;
+
+		val = readl(base + offset);
+		bit_val = (val & bit_mask) ? 1 : 0;
+		if (bit_val == want)
+			return 0;	/* success */
+		udelay(1);
+	}
+
+	debug("%s: timeout on addr 0x%p, waiting for bit %d to go to %d\n",
+	      __func__, base + offset, bit, want);
+
+	return -ETIMEDOUT;
+}
+
+/* Enable a peripheral clock */
+static int peri_clk_enable(struct clk *c, int enable)
+{
+	int ret = 0;
+	u32 reg;
+	struct peri_clock *peri_clk = to_peri_clk(c);
+	struct peri_clk_data *cd = peri_clk->data;
+	struct bcm_clk_gate *gate = &cd->gate;
+	void *base = (void *)c->ccu_clk_mgr_base;
+
+
+	debug("%s: %s\n", __func__, c->name);
+
+	clk_get_rate(c);	/* Make sure rate and sel are filled in */
+
+	/* enable access */
+	writel(CLK_WR_ACCESS_PASSWORD, base + WR_ACCESS_OFFSET);
+
+	if (enable) {
+		debug("%s %s set rate %lu div %lu sel %d parent %lu\n",
+		      __func__, c->name, c->rate, c->div, c->sel,
+		      c->parent->rate);
+
+		/*
+		 * clkgate - only software controllable gates are
+		 * supported by u-boot which includes all clocks
+		 * that matter. This avoids bringing in a lot of extra
+		 * complexity as done in the kernel framework.
+		 */
+		if (gate_exists(gate)) {
+			reg = readl(base + cd->gate.offset);
+			reg |= (1 << cd->gate.en_bit);
+			writel(reg, base + cd->gate.offset);
+		}
+
+		/* div and pll select */
+		if (divider_exists(&cd->div)) {
+			reg = readl(base + cd->div.offset);
+			bitfield_replace(reg, cd->div.shift, cd->div.width,
+					 c->div - 1);
+			writel(reg, base + cd->div.offset);
+		}
+
+		/* frequency selector */
+		if (selector_exists(&cd->sel)) {
+			reg = readl(base + cd->sel.offset);
+			bitfield_replace(reg, cd->sel.shift, cd->sel.width,
+					 c->sel);
+			writel(reg, base + cd->sel.offset);
+		}
+
+		/* trigger */
+		if (trigger_exists(&cd->trig)) {
+			writel((1 << cd->trig.bit), base + cd->trig.offset);
+
+			/* wait for trigger status bit to go to 0 */
+			ret = wait_bit(base, cd->trig.offset, cd->trig.bit, 0);
+			if (ret)
+				return ret;
+		}
+
+		/* wait for running (status_bit = 1) */
+		ret = wait_bit(base, cd->gate.offset, cd->gate.status_bit, 1);
+		if (ret)
+			return ret;
+	} else {
+		debug("%s disable clock %s\n", __func__, c->name);
+
+		/* clkgate */
+		reg = readl(base + cd->gate.offset);
+		reg &= ~(1 << cd->gate.en_bit);
+		writel(reg, base + cd->gate.offset);
+
+		/* wait for stop (status_bit = 0) */
+		ret = wait_bit(base, cd->gate.offset, cd->gate.status_bit, 0);
+	}
+
+	/* disable access */
+	writel(0, base + WR_ACCESS_OFFSET);
+
+	return ret;
+}
+
+/* Set the rate of a peripheral clock */
+static int peri_clk_set_rate(struct clk *c, unsigned long rate)
+{
+	int ret = 0;
+	int i;
+	unsigned long diff;
+	unsigned long new_rate = 0, div = 1;
+	struct peri_clock *peri_clk = to_peri_clk(c);
+	struct peri_clk_data *cd = peri_clk->data;
+	const char **clock;
+
+	debug("%s: %s\n", __func__, c->name);
+	diff = rate;
+
+	i = 0;
+	for (clock = cd->clocks; *clock; clock++, i++) {
+		struct refclk *ref = refclk_str_to_clk(*clock);
+		if (!ref) {
+			printf("%s: Lookup of %s failed\n", __func__, *clock);
+			return -EINVAL;
+		}
+
+		/* round to the new rate */
+		div = ref->clk.rate / rate;
+		if (div == 0)
+			div = 1;
+
+		new_rate = ref->clk.rate / div;
+
+		/* get the min diff */
+		if (abs(new_rate - rate) < diff) {
+			diff = abs(new_rate - rate);
+			c->sel = i;
+			c->parent = &ref->clk;
+			c->rate = new_rate;
+			c->div = div;
+		}
+	}
+
+	debug("%s %s set rate %lu div %lu sel %d parent %lu\n", __func__,
+	      c->name, c->rate, c->div, c->sel, c->parent->rate);
+	return ret;
+}
+
+/* Get the rate of a peripheral clock */
+static unsigned long peri_clk_get_rate(struct clk *c)
+{
+	struct peri_clock *peri_clk = to_peri_clk(c);
+	struct peri_clk_data *cd = peri_clk->data;
+	void *base = (void *)c->ccu_clk_mgr_base;
+	int div = 1;
+	const char **clock;
+	struct refclk *ref;
+	u32 reg;
+
+	debug("%s: %s\n", __func__, c->name);
+	if (selector_exists(&cd->sel)) {
+		reg = readl(base + cd->sel.offset);
+		c->sel = bitfield_extract(reg, cd->sel.shift, cd->sel.width);
+	} else {
+		/*
+		 * For peri clocks that don't have a selector, the single
+		 * reference clock will always exist at index 0.
+		 */
+		c->sel = 0;
+	}
+
+	if (divider_exists(&cd->div)) {
+		reg = readl(base + cd->div.offset);
+		div = bitfield_extract(reg, cd->div.shift, cd->div.width);
+		div += 1;
+	}
+
+	clock = cd->clocks;
+	ref = refclk_str_to_clk(clock[c->sel]);
+	if (!ref) {
+		printf("%s: Can't lookup %s\n", __func__, clock[c->sel]);
+		return 0;
+	}
+
+	c->parent = &ref->clk;
+	c->div = div;
+	c->rate = c->parent->rate / c->div;
+	debug("%s parent rate %lu div %d sel %d rate %lu\n", __func__,
+	      c->parent->rate, div, c->sel, c->rate);
+
+	return c->rate;
+}
+
+/* Peripheral clock operations */
+struct clk_ops peri_clk_ops = {
+	.enable = peri_clk_enable,
+	.set_rate = peri_clk_set_rate,
+	.get_rate = peri_clk_get_rate,
+};
+
+/* Enable a CCU clock */
+static int ccu_clk_enable(struct clk *c, int enable)
+{
+	struct ccu_clock *ccu_clk = to_ccu_clk(c);
+	void *base = (void *)c->ccu_clk_mgr_base;
+	int ret = 0;
+	u32 reg;
+
+	debug("%s: %s\n", __func__, c->name);
+	if (!enable)
+		return -EINVAL;	/* CCU clock cannot shutdown */
+
+	/* enable access */
+	writel(CLK_WR_ACCESS_PASSWORD, base + WR_ACCESS_OFFSET);
+
+	/* config enable for policy engine */
+	writel(1, base + ccu_clk->lvm_en_offset);
+
+	/* wait for bit to go to 0 */
+	ret = wait_bit(base, ccu_clk->lvm_en_offset, 0, 0);
+	if (ret)
+		return ret;
+
+	/* freq ID */
+	if (!ccu_clk->freq_bit_shift)
+		ccu_clk->freq_bit_shift = 8;
+
+	/* Set frequency id for each of the 4 policies */
+	reg = ccu_clk->freq_id |
+	    (ccu_clk->freq_id << (ccu_clk->freq_bit_shift)) |
+	    (ccu_clk->freq_id << (ccu_clk->freq_bit_shift * 2)) |
+	    (ccu_clk->freq_id << (ccu_clk->freq_bit_shift * 3));
+	writel(reg, base + ccu_clk->policy_freq_offset);
+
+	/* enable all clock mask */
+	writel(0x7fffffff, base + ccu_clk->policy0_mask_offset);
+	writel(0x7fffffff, base + ccu_clk->policy1_mask_offset);
+	writel(0x7fffffff, base + ccu_clk->policy2_mask_offset);
+	writel(0x7fffffff, base + ccu_clk->policy3_mask_offset);
+
+	if (ccu_clk->num_policy_masks == 2) {
+		writel(0x7fffffff, base + ccu_clk->policy0_mask2_offset);
+		writel(0x7fffffff, base + ccu_clk->policy1_mask2_offset);
+		writel(0x7fffffff, base + ccu_clk->policy2_mask2_offset);
+		writel(0x7fffffff, base + ccu_clk->policy3_mask2_offset);
+	}
+
+	/* start policy engine */
+	reg = readl(base + ccu_clk->policy_ctl_offset);
+	reg |= (POLICY_CTL_GO + POLICY_CTL_GO_ATL);
+	writel(reg, base + ccu_clk->policy_ctl_offset);
+
+	/* wait till started */
+	ret = wait_bit(base, ccu_clk->policy_ctl_offset, 0, 0);
+	if (ret)
+		return ret;
+
+	/* disable access */
+	writel(0, base + WR_ACCESS_OFFSET);
+
+	return ret;
+}
+
+/* Get the CCU clock rate */
+static unsigned long ccu_clk_get_rate(struct clk *c)
+{
+	struct ccu_clock *ccu_clk = to_ccu_clk(c);
+	debug("%s: %s\n", __func__, c->name);
+	c->rate = ccu_clk->freq_tbl[ccu_clk->freq_id];
+	return c->rate;
+}
+
+/* CCU clock operations */
+struct clk_ops ccu_clk_ops = {
+	.enable = ccu_clk_enable,
+	.get_rate = ccu_clk_get_rate,
+};
+
+/* Enable a bus clock */
+static int bus_clk_enable(struct clk *c, int enable)
+{
+	struct bus_clock *bus_clk = to_bus_clk(c);
+	struct bus_clk_data *cd = bus_clk->data;
+	void *base = (void *)c->ccu_clk_mgr_base;
+	int ret = 0;
+	u32 reg;
+
+	debug("%s: %s\n", __func__, c->name);
+	/* enable access */
+	writel(CLK_WR_ACCESS_PASSWORD, base + WR_ACCESS_OFFSET);
+
+	/* enable gating */
+	reg = readl(base + cd->gate.offset);
+	if (!!(reg & (1 << cd->gate.status_bit)) == !!enable)
+		debug("%s already %s\n", c->name,
+		      enable ? "enabled" : "disabled");
+	else {
+		int want = (enable) ? 1 : 0;
+		reg |= (1 << cd->gate.hw_sw_sel_bit);
+
+		if (enable)
+			reg |= (1 << cd->gate.en_bit);
+		else
+			reg &= ~(1 << cd->gate.en_bit);
+
+		writel(reg, base + cd->gate.offset);
+		ret = wait_bit(base, cd->gate.offset, cd->gate.status_bit,
+			       want);
+		if (ret)
+			return ret;
+	}
+
+	/* disable access */
+	writel(0, base + WR_ACCESS_OFFSET);
+
+	return ret;
+}
+
+/* Get the rate of a bus clock */
+static unsigned long bus_clk_get_rate(struct clk *c)
+{
+	struct bus_clock *bus_clk = to_bus_clk(c);
+	struct ccu_clock *ccu_clk;
+
+	debug("%s: %s\n", __func__, c->name);
+	ccu_clk = to_ccu_clk(c->parent);
+
+	c->rate = bus_clk->freq_tbl[ccu_clk->freq_id];
+	c->div = ccu_clk->freq_tbl[ccu_clk->freq_id] / c->rate;
+	return c->rate;
+}
+
+/* Bus clock operations */
+struct clk_ops bus_clk_ops = {
+	.enable = bus_clk_enable,
+	.get_rate = bus_clk_get_rate,
+};
+
+/* Enable a reference clock */
+static int ref_clk_enable(struct clk *c, int enable)
+{
+	debug("%s: %s\n", __func__, c->name);
+	return 0;
+}
+
+/* Reference clock operations */
+struct clk_ops ref_clk_ops = {
+	.enable = ref_clk_enable,
+};
+
+/*
+ * clk.h implementation follows
+ */
+
+/* Initialize the clock framework */
+int clk_init(void)
+{
+	debug("%s:\n", __func__);
+	return 0;
+}
+
+/* Get a clock handle, give a name string */
+struct clk *clk_get(const char *con_id)
+{
+	int i;
+	struct clk_lookup *clk_tblp;
+
+	debug("%s: %s\n", __func__, con_id);
+
+	clk_tblp = arch_clk_tbl;
+	for (i = 0; i < arch_clk_tbl_array_size; i++, clk_tblp++) {
+		if (clk_tblp->con_id) {
+			if (!con_id || strcmp(clk_tblp->con_id, con_id))
+				continue;
+			return clk_tblp->clk;
+		}
+	}
+	return NULL;
+}
+
+/* Enable a clock */
+int clk_enable(struct clk *c)
+{
+	int ret = 0;
+
+	debug("%s: %s\n", __func__, c->name);
+	if (!c->ops || !c->ops->enable)
+		return -1;
+
+	/* enable parent clock first */
+	if (c->parent)
+		ret = clk_enable(c->parent);
+
+	if (ret)
+		return ret;
+
+	if (!c->use_cnt) {
+		c->use_cnt++;
+		ret = c->ops->enable(c, 1);
+	}
+
+	return ret;
+}
+
+/* Disable a clock */
+void clk_disable(struct clk *c)
+{
+	debug("%s: %s\n", __func__, c->name);
+	if (!c->ops || !c->ops->enable)
+		return;
+
+	if (c->use_cnt) {
+		c->use_cnt--;
+		c->ops->enable(c, 0);
+	}
+
+	/* disable parent */
+	if (c->parent)
+		clk_disable(c->parent);
+}
+
+/* Get the clock rate */
+unsigned long clk_get_rate(struct clk *c)
+{
+	unsigned long rate;
+
+	debug("%s: %s\n", __func__, c->name);
+	if (!c || !c->ops || !c->ops->get_rate)
+		return 0;
+
+	rate = c->ops->get_rate(c);
+	debug("%s: rate = %ld\n", __func__, rate);
+	return rate;
+}
+
+/* Set the clock rate */
+int clk_set_rate(struct clk *c, unsigned long rate)
+{
+	int ret;
+
+	debug("%s: %s rate=%ld\n", __func__, c->name, rate);
+	if (!c || !c->ops || !c->ops->set_rate)
+		return -EINVAL;
+
+	if (c->use_cnt)
+		return -EINVAL;
+
+	ret = c->ops->set_rate(c, rate);
+
+	return ret;
+}
+
+/* Not required for this arch */
+/*
+long clk_round_rate(struct clk *clk, unsigned long rate);
+int clk_set_parent(struct clk *clk, struct clk *parent);
+struct clk *clk_get_parent(struct clk *clk);
+*/