u-boot/arch/arm/mach-tegra/clock.c

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/*
* Copyright (c) 2010-2014, 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/ap.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_31_30_MASK;
value |= source << OUT_CLK_SOURCE_31_30_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_31_30_MASK,
source << OUT_CLK_SOURCE_31_30_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;
switch (mux_bits) {
case MASK_BITS_31_30:
clrsetbits_le32(reg, OUT_CLK_SOURCE_31_30_MASK,
source << OUT_CLK_SOURCE_31_30_SHIFT);
break;
case MASK_BITS_31_29:
clrsetbits_le32(reg, OUT_CLK_SOURCE_31_29_MASK,
source << OUT_CLK_SOURCE_31_29_SHIFT);
break;
case MASK_BITS_31_28:
clrsetbits_le32(reg, OUT_CLK_SOURCE_31_28_MASK,
source << OUT_CLK_SOURCE_31_28_SHIFT);
break;
default:
return -1;
}
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;
int xdiv = 0;
/* work out the source clock and set it */
source = get_periph_clock_source(periph_id, parent, &mux_bits,
&divider_bits);
divider = find_best_divider(divider_bits, pll_rate[parent],
rate, &xdiv);
if (extra_div)
*extra_div = xdiv;
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]);
/* Do any special system timer/TSC setup */
#if defined(CONFIG_TEGRA_SUPPORT_NON_SECURE)
if (!tegra_cpu_is_non_secure())
#endif
arch_timer_init();
}
static void set_avp_clock_source(u32 src)
{
struct clk_rst_ctlr *clkrst =
(struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
u32 val;
val = (src << SCLK_SWAKEUP_FIQ_SOURCE_SHIFT) |
(src << SCLK_SWAKEUP_IRQ_SOURCE_SHIFT) |
(src << SCLK_SWAKEUP_RUN_SOURCE_SHIFT) |
(src << SCLK_SWAKEUP_IDLE_SOURCE_SHIFT) |
(SCLK_SYS_STATE_RUN << SCLK_SYS_STATE_SHIFT);
writel(val, &clkrst->crc_sclk_brst_pol);
udelay(3);
}
/*
* This function is useful on Tegra30, and any later SoCs that have compatible
* PLLP configuration registers.
*/
void tegra30_set_up_pllp(void)
{
struct clk_rst_ctlr *clkrst = (struct clk_rst_ctlr *)NV_PA_CLK_RST_BASE;
u32 reg;
/*
* Based on the Tegra TRM, the system clock (which is the AVP clock) can
* run up to 275MHz. On power on, the default sytem clock source is set
* to PLLP_OUT0. This function sets PLLP's (hence PLLP_OUT0's) rate to
* 408MHz which is beyond system clock's upper limit.
*
* The fix is to set the system clock to CLK_M before initializing PLLP,
* and then switch back to PLLP_OUT4, which has an appropriate divider
* configured, after PLLP has been configured
*/
set_avp_clock_source(SCLK_SOURCE_CLKM);
/*
* PLLP output frequency set to 408Mhz
* PLLC output frequency set to 228Mhz
*/
switch (clock_get_osc_freq()) {
case CLOCK_OSC_FREQ_12_0: /* OSC is 12Mhz */
clock_set_rate(CLOCK_ID_PERIPH, 408, 12, 0, 8);
clock_set_rate(CLOCK_ID_CGENERAL, 456, 12, 1, 8);
break;
case CLOCK_OSC_FREQ_26_0: /* OSC is 26Mhz */
clock_set_rate(CLOCK_ID_PERIPH, 408, 26, 0, 8);
clock_set_rate(CLOCK_ID_CGENERAL, 600, 26, 0, 8);
break;
case CLOCK_OSC_FREQ_13_0: /* OSC is 13Mhz */
clock_set_rate(CLOCK_ID_PERIPH, 408, 13, 0, 8);
clock_set_rate(CLOCK_ID_CGENERAL, 600, 13, 0, 8);
break;
case CLOCK_OSC_FREQ_19_2:
default:
/*
* These are not supported. It is too early to print a
* message and the UART likely won't work anyway due to the
* oscillator being wrong.
*/
break;
}
/* Set PLLP_OUT1, 2, 3 & 4 freqs to 9.6, 48, 102 & 204MHz */
/* OUT1, 2 */
/* Assert RSTN before enable */
reg = PLLP_OUT2_RSTN_EN | PLLP_OUT1_RSTN_EN;
writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[0]);
/* Set divisor and reenable */
reg = (IN_408_OUT_48_DIVISOR << PLLP_OUT2_RATIO)
| PLLP_OUT2_OVR | PLLP_OUT2_CLKEN | PLLP_OUT2_RSTN_DIS
| (IN_408_OUT_9_6_DIVISOR << PLLP_OUT1_RATIO)
| PLLP_OUT1_OVR | PLLP_OUT1_CLKEN | PLLP_OUT1_RSTN_DIS;
writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[0]);
/* OUT3, 4 */
/* Assert RSTN before enable */
reg = PLLP_OUT4_RSTN_EN | PLLP_OUT3_RSTN_EN;
writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[1]);
/* Set divisor and reenable */
reg = (IN_408_OUT_204_DIVISOR << PLLP_OUT4_RATIO)
| PLLP_OUT4_OVR | PLLP_OUT4_CLKEN | PLLP_OUT4_RSTN_DIS
| (IN_408_OUT_102_DIVISOR << PLLP_OUT3_RATIO)
| PLLP_OUT3_OVR | PLLP_OUT3_CLKEN | PLLP_OUT3_RSTN_DIS;
writel(reg, &clkrst->crc_pll[CLOCK_ID_PERIPH].pll_out[1]);
set_avp_clock_source(SCLK_SOURCE_PLLP_OUT4);
}