diff options
Diffstat (limited to 'arch/arm/cpu/tegra-common')
-rw-r--r-- | arch/arm/cpu/tegra-common/Makefile | 2 | ||||
-rw-r--r-- | arch/arm/cpu/tegra-common/clock.c | 560 |
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, + ÷r_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]); +} |