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authorTom Warren <twarren@nvidia.com>2013-01-23 14:01:01 -0700
committerTom Warren <twarren@nvidia.com>2013-02-11 10:35:24 -0700
commitf29f086a098a8462f8b375da0509246843f7fdd1 (patch)
tree8a8b14f6e45bc232e0aea4668b07129f025ce311 /arch/arm/cpu/tegra-common
parentd83152d8e42940d193589b351f874a8600335468 (diff)
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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>
Diffstat (limited to 'arch/arm/cpu/tegra-common')
-rw-r--r--arch/arm/cpu/tegra-common/Makefile2
-rw-r--r--arch/arm/cpu/tegra-common/clock.c560
2 files changed, 561 insertions, 1 deletions
diff --git a/arch/arm/cpu/tegra-common/Makefile b/arch/arm/cpu/tegra-common/Makefile
index 38e90d3..8e95c7e 100644
--- a/arch/arm/cpu/tegra-common/Makefile
+++ b/arch/arm/cpu/tegra-common/Makefile
@@ -28,7 +28,7 @@ include $(TOPDIR)/config.mk
LIB = $(obj)libcputegra-common.o
SOBJS += lowlevel_init.o
-COBJS-y += ap.o board.o sys_info.o timer.o
+COBJS-y += ap.o board.o sys_info.o timer.o clock.o
SRCS := $(SOBJS:.o=.S) $(COBJS-y:.o=.c)
OBJS := $(addprefix $(obj),$(SOBJS) $(COBJS-y))
diff --git a/arch/arm/cpu/tegra-common/clock.c b/arch/arm/cpu/tegra-common/clock.c
new file mode 100644
index 0000000..49a0633
--- /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]);
+}