Tegra: Move common clock code to arch/arm/cpu/tegra-common/clock.c

This 'commonizes' much of the clock/pll code. SoC-dependent code
and tables are left in arch/cpu/tegraXXX-common/clock.c

Some T30 tables needed whitespace fixes due to checkpatch complaints.

Signed-off-by: Tom Warren <twarren@nvidia.com>

1 files changed, 560 insertions, 0 deletions

diff --git a/arch/arm/cpu/tegra-common/clock.c b/arch/arm/cpu/tegra-common/clock.c
new file mode 100644
index 000000000..49a06334c
--- /dev/null
+++ b/arch/arm/cpu/tegra-common/clock.c
@@ -0,0 +1,560 @@
+/*
+ * Copyright (c) 2010-2013, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* Tegra SoC common clock control functions */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/tegra.h>
+#include <asm/arch-tegra/clk_rst.h>
+#include <asm/arch-tegra/timer.h>
+#include <div64.h>
+#include <fdtdec.h>
+
+/*
+ * This is our record of the current clock rate of each clock. We don't
+ * fill all of these in since we are only really interested in clocks which
+ * we use as parents.
+ */
+static unsigned pll_rate[CLOCK_ID_COUNT];
+
+/*
+ * The oscillator frequency is fixed to one of four set values. Based on this
+ * the other clocks are set up appropriately.
+ */
+static unsigned osc_freq[CLOCK_OSC_FREQ_COUNT] = {
+	13000000,
+	19200000,
+	12000000,
+	26000000,
+};
+
+/* return 1 if a peripheral ID is in range */
+#define clock_type_id_isvalid(id) ((id) >= 0 && \
+		(id) < CLOCK_TYPE_COUNT)
+
+char pllp_valid = 1;	/* PLLP is set up correctly */
+
+/* return 1 if a periphc_internal_id is in range */
+#define periphc_internal_id_isvalid(id) ((id) >= 0 && \
+		(id) < PERIPHC_COUNT)
+
+/* number of clock outputs of a PLL */
+static const u8 pll_num_clkouts[] = {
+	1,	/* PLLC */
+	1,	/* PLLM */
+	4,	/* PLLP */
+	1,	/* PLLA */
+	0,	/* PLLU */
+	0,	/* PLLD */
+};
+
+int clock_get_osc_bypass(void)
+{
+	struct clk_rst_ctlr *clkrst =
+			(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 reg;
+
+	reg = readl(&clkrst->crc_osc_ctrl);
+	return (reg & OSC_XOBP_MASK) >> OSC_XOBP_SHIFT;
+}
+
+/* Returns a pointer to the registers of the given pll */
+static struct clk_pll *get_pll(enum clock_id clkid)
+{
+	struct clk_rst_ctlr *clkrst =
+			(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+
+	assert(clock_id_is_pll(clkid));
+	return &clkrst->crc_pll[clkid];
+}
+
+int clock_ll_read_pll(enum clock_id clkid, u32 *divm, u32 *divn,
+		u32 *divp, u32 *cpcon, u32 *lfcon)
+{
+	struct clk_pll *pll = get_pll(clkid);
+	u32 data;
+
+	assert(clkid != CLOCK_ID_USB);
+
+	/* Safety check, adds to code size but is small */
+	if (!clock_id_is_pll(clkid) || clkid == CLOCK_ID_USB)
+		return -1;
+	data = readl(&pll->pll_base);
+	*divm = (data & PLL_DIVM_MASK) >> PLL_DIVM_SHIFT;
+	*divn = (data & PLL_DIVN_MASK) >> PLL_DIVN_SHIFT;
+	*divp = (data & PLL_DIVP_MASK) >> PLL_DIVP_SHIFT;
+	data = readl(&pll->pll_misc);
+	*cpcon = (data & PLL_CPCON_MASK) >> PLL_CPCON_SHIFT;
+	*lfcon = (data & PLL_LFCON_MASK) >> PLL_LFCON_SHIFT;
+
+	return 0;
+}
+
+unsigned long clock_start_pll(enum clock_id clkid, u32 divm, u32 divn,
+		u32 divp, u32 cpcon, u32 lfcon)
+{
+	struct clk_pll *pll = get_pll(clkid);
+	u32 data;
+
+	/*
+	 * We cheat by treating all PLL (except PLLU) in the same fashion.
+	 * This works only because:
+	 * - same fields are always mapped at same offsets, except DCCON
+	 * - DCCON is always 0, doesn't conflict
+	 * - M,N, P of PLLP values are ignored for PLLP
+	 */
+	data = (cpcon << PLL_CPCON_SHIFT) | (lfcon << PLL_LFCON_SHIFT);
+	writel(data, &pll->pll_misc);
+
+	data = (divm << PLL_DIVM_SHIFT) | (divn << PLL_DIVN_SHIFT) |
+			(0 << PLL_BYPASS_SHIFT) | (1 << PLL_ENABLE_SHIFT);
+
+	if (clkid == CLOCK_ID_USB)
+		data |= divp << PLLU_VCO_FREQ_SHIFT;
+	else
+		data |= divp << PLL_DIVP_SHIFT;
+	writel(data, &pll->pll_base);
+
+	/* calculate the stable time */
+	return timer_get_us() + CLOCK_PLL_STABLE_DELAY_US;
+}
+
+void clock_ll_set_source_divisor(enum periph_id periph_id, unsigned source,
+			unsigned divisor)
+{
+	u32 *reg = get_periph_source_reg(periph_id);
+	u32 value;
+
+	value = readl(reg);
+
+	value &= ~OUT_CLK_SOURCE_MASK;
+	value |= source << OUT_CLK_SOURCE_SHIFT;
+
+	value &= ~OUT_CLK_DIVISOR_MASK;
+	value |= divisor << OUT_CLK_DIVISOR_SHIFT;
+
+	writel(value, reg);
+}
+
+void clock_ll_set_source(enum periph_id periph_id, unsigned source)
+{
+	u32 *reg = get_periph_source_reg(periph_id);
+
+	clrsetbits_le32(reg, OUT_CLK_SOURCE_MASK,
+			source << OUT_CLK_SOURCE_SHIFT);
+}
+
+/**
+ * Given the parent's rate and the required rate for the children, this works
+ * out the peripheral clock divider to use, in 7.1 binary format.
+ *
+ * @param divider_bits	number of divider bits (8 or 16)
+ * @param parent_rate	clock rate of parent clock in Hz
+ * @param rate		required clock rate for this clock
+ * @return divider which should be used
+ */
+static int clk_get_divider(unsigned divider_bits, unsigned long parent_rate,
+			   unsigned long rate)
+{
+	u64 divider = parent_rate * 2;
+	unsigned max_divider = 1 << divider_bits;
+
+	divider += rate - 1;
+	do_div(divider, rate);
+
+	if ((s64)divider - 2 < 0)
+		return 0;
+
+	if ((s64)divider - 2 >= max_divider)
+		return -1;
+
+	return divider - 2;
+}
+
+int clock_set_pllout(enum clock_id clkid, enum pll_out_id pllout, unsigned rate)
+{
+	struct clk_pll *pll = get_pll(clkid);
+	int data = 0, div = 0, offset = 0;
+
+	if (!clock_id_is_pll(clkid))
+		return -1;
+
+	if (pllout + 1 > pll_num_clkouts[clkid])
+		return -1;
+
+	div = clk_get_divider(8, pll_rate[clkid], rate);
+
+	if (div < 0)
+		return -1;
+
+	/* out2 and out4 are in the high part of the register */
+	if (pllout == PLL_OUT2 || pllout == PLL_OUT4)
+		offset = 16;
+
+	data = (div << PLL_OUT_RATIO_SHIFT) |
+			PLL_OUT_OVRRIDE | PLL_OUT_CLKEN | PLL_OUT_RSTN;
+	clrsetbits_le32(&pll->pll_out[pllout >> 1],
+			PLL_OUT_RATIO_MASK << offset, data << offset);
+
+	return 0;
+}
+
+/**
+ * Given the parent's rate and the divider in 7.1 format, this works out the
+ * resulting peripheral clock rate.
+ *
+ * @param parent_rate	clock rate of parent clock in Hz
+ * @param divider which should be used in 7.1 format
+ * @return effective clock rate of peripheral
+ */
+static unsigned long get_rate_from_divider(unsigned long parent_rate,
+					   int divider)
+{
+	u64 rate;
+
+	rate = (u64)parent_rate * 2;
+	do_div(rate, divider + 2);
+	return rate;
+}
+
+unsigned long clock_get_periph_rate(enum periph_id periph_id,
+		enum clock_id parent)
+{
+	u32 *reg = get_periph_source_reg(periph_id);
+
+	return get_rate_from_divider(pll_rate[parent],
+		(readl(reg) & OUT_CLK_DIVISOR_MASK) >> OUT_CLK_DIVISOR_SHIFT);
+}
+
+/**
+ * Find the best available 7.1 format divisor given a parent clock rate and
+ * required child clock rate. This function assumes that a second-stage
+ * divisor is available which can divide by powers of 2 from 1 to 256.
+ *
+ * @param divider_bits	number of divider bits (8 or 16)
+ * @param parent_rate	clock rate of parent clock in Hz
+ * @param rate		required clock rate for this clock
+ * @param extra_div	value for the second-stage divisor (not set if this
+ *			function returns -1.
+ * @return divider which should be used, or -1 if nothing is valid
+ *
+ */
+static int find_best_divider(unsigned divider_bits, unsigned long parent_rate,
+				unsigned long rate, int *extra_div)
+{
+	int shift;
+	int best_divider = -1;
+	int best_error = rate;
+
+	/* try dividers from 1 to 256 and find closest match */
+	for (shift = 0; shift <= 8 && best_error > 0; shift++) {
+		unsigned divided_parent = parent_rate >> shift;
+		int divider = clk_get_divider(divider_bits, divided_parent,
+						rate);
+		unsigned effective_rate = get_rate_from_divider(divided_parent,
+						divider);
+		int error = rate - effective_rate;
+
+		/* Given a valid divider, look for the lowest error */
+		if (divider != -1 && error < best_error) {
+			best_error = error;
+			*extra_div = 1 << shift;
+			best_divider = divider;
+		}
+	}
+
+	/* return what we found - *extra_div will already be set */
+	return best_divider;
+}
+
+/**
+ * Adjust peripheral PLL to use the given divider and source.
+ *
+ * @param periph_id	peripheral to adjust
+ * @param source	Source number (0-3 or 0-7)
+ * @param mux_bits	Number of mux bits (2 or 4)
+ * @param divider	Required divider in 7.1 or 15.1 format
+ * @return 0 if ok, -1 on error (requesting a parent clock which is not valid
+ *		for this peripheral)
+ */
+static int adjust_periph_pll(enum periph_id periph_id, int source,
+				int mux_bits, unsigned divider)
+{
+	u32 *reg = get_periph_source_reg(periph_id);
+
+	clrsetbits_le32(reg, OUT_CLK_DIVISOR_MASK,
+			divider << OUT_CLK_DIVISOR_SHIFT);
+	udelay(1);
+
+	/* work out the source clock and set it */
+	if (source < 0)
+		return -1;
+	if (mux_bits == 4) {
+		clrsetbits_le32(reg, OUT_CLK_SOURCE4_MASK,
+			source << OUT_CLK_SOURCE4_SHIFT);
+	} else {
+		clrsetbits_le32(reg, OUT_CLK_SOURCE_MASK,
+			source << OUT_CLK_SOURCE_SHIFT);
+	}
+	udelay(2);
+	return 0;
+}
+
+unsigned clock_adjust_periph_pll_div(enum periph_id periph_id,
+		enum clock_id parent, unsigned rate, int *extra_div)
+{
+	unsigned effective_rate;
+	int mux_bits, divider_bits, source;
+	int divider;
+
+	/* work out the source clock and set it */
+	source = get_periph_clock_source(periph_id, parent, &mux_bits,
+					 &divider_bits);
+
+	if (extra_div)
+		divider = find_best_divider(divider_bits, pll_rate[parent],
+						rate, extra_div);
+	else
+		divider = clk_get_divider(divider_bits, pll_rate[parent],
+					  rate);
+	assert(divider >= 0);
+	if (adjust_periph_pll(periph_id, source, mux_bits, divider))
+		return -1U;
+	debug("periph %d, rate=%d, reg=%p = %x\n", periph_id, rate,
+		get_periph_source_reg(periph_id),
+		readl(get_periph_source_reg(periph_id)));
+
+	/* Check what we ended up with. This shouldn't matter though */
+	effective_rate = clock_get_periph_rate(periph_id, parent);
+	if (extra_div)
+		effective_rate /= *extra_div;
+	if (rate != effective_rate)
+		debug("Requested clock rate %u not honored (got %u)\n",
+			rate, effective_rate);
+	return effective_rate;
+}
+
+unsigned clock_start_periph_pll(enum periph_id periph_id,
+		enum clock_id parent, unsigned rate)
+{
+	unsigned effective_rate;
+
+	reset_set_enable(periph_id, 1);
+	clock_enable(periph_id);
+
+	effective_rate = clock_adjust_periph_pll_div(periph_id, parent, rate,
+						 NULL);
+
+	reset_set_enable(periph_id, 0);
+	return effective_rate;
+}
+
+void clock_enable(enum periph_id clkid)
+{
+	clock_set_enable(clkid, 1);
+}
+
+void clock_disable(enum periph_id clkid)
+{
+	clock_set_enable(clkid, 0);
+}
+
+void reset_periph(enum periph_id periph_id, int us_delay)
+{
+	/* Put peripheral into reset */
+	reset_set_enable(periph_id, 1);
+	udelay(us_delay);
+
+	/* Remove reset */
+	reset_set_enable(periph_id, 0);
+
+	udelay(us_delay);
+}
+
+void reset_cmplx_set_enable(int cpu, int which, int reset)
+{
+	struct clk_rst_ctlr *clkrst =
+			(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
+	u32 mask;
+
+	/* Form the mask, which depends on the cpu chosen (2 or 4) */
+	assert(cpu >= 0 && cpu < MAX_NUM_CPU);
+	mask = which << cpu;
+
+	/* either enable or disable those reset for that CPU */
+	if (reset)
+		writel(mask, &clkrst->crc_cpu_cmplx_set);
+	else
+		writel(mask, &clkrst->crc_cpu_cmplx_clr);
+}
+
+unsigned clock_get_rate(enum clock_id clkid)
+{
+	struct clk_pll *pll;
+	u32 base;
+	u32 divm;
+	u64 parent_rate;
+	u64 rate;
+
+	parent_rate = osc_freq[clock_get_osc_freq()];
+	if (clkid == CLOCK_ID_OSC)
+		return parent_rate;
+
+	pll = get_pll(clkid);
+	base = readl(&pll->pll_base);
+
+	/* Oh for bf_unpack()... */
+	rate = parent_rate * ((base & PLL_DIVN_MASK) >> PLL_DIVN_SHIFT);
+	divm = (base & PLL_DIVM_MASK) >> PLL_DIVM_SHIFT;
+	if (clkid == CLOCK_ID_USB)
+		divm <<= (base & PLLU_VCO_FREQ_MASK) >> PLLU_VCO_FREQ_SHIFT;
+	else
+		divm <<= (base & PLL_DIVP_MASK) >> PLL_DIVP_SHIFT;
+	do_div(rate, divm);
+	return rate;
+}
+
+/**
+ * Set the output frequency you want for each PLL clock.
+ * PLL output frequencies are programmed by setting their N, M and P values.
+ * The governing equations are:
+ *     VCO = (Fi / m) * n, Fo = VCO / (2^p)
+ *     where Fo is the output frequency from the PLL.
+ * Example: Set the output frequency to 216Mhz(Fo) with 12Mhz OSC(Fi)
+ *     216Mhz = ((12Mhz / m) * n) / (2^p) so n=432,m=12,p=1
+ * Please see Tegra TRM section 5.3 to get the detail for PLL Programming
+ *
+ * @param n PLL feedback divider(DIVN)
+ * @param m PLL input divider(DIVN)
+ * @param p post divider(DIVP)
+ * @param cpcon base PLL charge pump(CPCON)
+ * @return 0 if ok, -1 on error (the requested PLL is incorrect and cannot
+ *		be overriden), 1 if PLL is already correct
+ */
+int clock_set_rate(enum clock_id clkid, u32 n, u32 m, u32 p, u32 cpcon)
+{
+	u32 base_reg;
+	u32 misc_reg;
+	struct clk_pll *pll;
+
+	pll = get_pll(clkid);
+
+	base_reg = readl(&pll->pll_base);
+
+	/* Set BYPASS, m, n and p to PLL_BASE */
+	base_reg &= ~PLL_DIVM_MASK;
+	base_reg |= m << PLL_DIVM_SHIFT;
+
+	base_reg &= ~PLL_DIVN_MASK;
+	base_reg |= n << PLL_DIVN_SHIFT;
+
+	base_reg &= ~PLL_DIVP_MASK;
+	base_reg |= p << PLL_DIVP_SHIFT;
+
+	if (clkid == CLOCK_ID_PERIPH) {
+		/*
+		 * If the PLL is already set up, check that it is correct
+		 * and record this info for clock_verify() to check.
+		 */
+		if (base_reg & PLL_BASE_OVRRIDE_MASK) {
+			base_reg |= PLL_ENABLE_MASK;
+			if (base_reg != readl(&pll->pll_base))
+				pllp_valid = 0;
+			return pllp_valid ? 1 : -1;
+		}
+		base_reg |= PLL_BASE_OVRRIDE_MASK;
+	}
+
+	base_reg |= PLL_BYPASS_MASK;
+	writel(base_reg, &pll->pll_base);
+
+	/* Set cpcon to PLL_MISC */
+	misc_reg = readl(&pll->pll_misc);
+	misc_reg &= ~PLL_CPCON_MASK;
+	misc_reg |= cpcon << PLL_CPCON_SHIFT;
+	writel(misc_reg, &pll->pll_misc);
+
+	/* Enable PLL */
+	base_reg |= PLL_ENABLE_MASK;
+	writel(base_reg, &pll->pll_base);
+
+	/* Disable BYPASS */
+	base_reg &= ~PLL_BYPASS_MASK;
+	writel(base_reg, &pll->pll_base);
+
+	return 0;
+}
+
+void clock_ll_start_uart(enum periph_id periph_id)
+{
+	/* Assert UART reset and enable clock */
+	reset_set_enable(periph_id, 1);
+	clock_enable(periph_id);
+	clock_ll_set_source(periph_id, 0); /* UARTx_CLK_SRC = 00, PLLP_OUT0 */
+
+	/* wait for 2us */
+	udelay(2);
+
+	/* De-assert reset to UART */
+	reset_set_enable(periph_id, 0);
+}
+
+#ifdef CONFIG_OF_CONTROL
+int clock_decode_periph_id(const void *blob, int node)
+{
+	enum periph_id id;
+	u32 cell[2];
+	int err;
+
+	err = fdtdec_get_int_array(blob, node, "clocks", cell,
+				   ARRAY_SIZE(cell));
+	if (err)
+		return -1;
+	id = clk_id_to_periph_id(cell[1]);
+	assert(clock_periph_id_isvalid(id));
+	return id;
+}
+#endif /* CONFIG_OF_CONTROL */
+
+int clock_verify(void)
+{
+	struct clk_pll *pll = get_pll(CLOCK_ID_PERIPH);
+	u32 reg = readl(&pll->pll_base);
+
+	if (!pllp_valid) {
+		printf("Warning: PLLP %x is not correct\n", reg);
+		return -1;
+	}
+	debug("PLLP %x is correct\n", reg);
+	return 0;
+}
+
+void clock_init(void)
+{
+	pll_rate[CLOCK_ID_MEMORY] = clock_get_rate(CLOCK_ID_MEMORY);
+	pll_rate[CLOCK_ID_PERIPH] = clock_get_rate(CLOCK_ID_PERIPH);
+	pll_rate[CLOCK_ID_CGENERAL] = clock_get_rate(CLOCK_ID_CGENERAL);
+	pll_rate[CLOCK_ID_OSC] = clock_get_rate(CLOCK_ID_OSC);
+	pll_rate[CLOCK_ID_SFROM32KHZ] = 32768;
+	pll_rate[CLOCK_ID_XCPU] = clock_get_rate(CLOCK_ID_XCPU);
+	debug("Osc = %d\n", pll_rate[CLOCK_ID_OSC]);
+	debug("PLLM = %d\n", pll_rate[CLOCK_ID_MEMORY]);
+	debug("PLLP = %d\n", pll_rate[CLOCK_ID_PERIPH]);
+	debug("PLLC = %d\n", pll_rate[CLOCK_ID_CGENERAL]);
+	debug("PLLX = %d\n", pll_rate[CLOCK_ID_XCPU]);
+}