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u-boot/drivers/clk/clk_pic32.c
Purna Chandra Mandal a0e7908326 drivers: clk: Add clock driver for Microchip PIC32 Microcontroller. 
PIC32 clock module consists of multiple oscillators, PLLs, mutiplexers
and dividers capable of supplying clock to various controllers
on or off-chip.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
2016-02-01 22:14:00 +01:00

433 lines
9.2 KiB
C
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/*
* Copyright (C) 2015 Purna Chandra Mandal <purna.mandal@microchip.com>
*
* SPDX-License-Identifier: GPL-2.0+
*
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <div64.h>
#include <wait_bit.h>
#include <dm/lists.h>
#include <asm/io.h>
#include <mach/pic32.h>
#include <dt-bindings/clock/microchip,clock.h>
DECLARE_GLOBAL_DATA_PTR;
/* Primary oscillator */
#define SYS_POSC_CLK_HZ 24000000
/* FRC clk rate */
#define SYS_FRC_CLK_HZ 8000000
/* Clock Registers */
#define OSCCON 0x0000
#define OSCTUNE 0x0010
#define SPLLCON 0x0020
#define REFO1CON 0x0080
#define REFO1TRIM 0x0090
#define PB1DIV 0x0140
/* SPLL */
#define ICLK_MASK 0x00000080
#define PLLIDIV_MASK 0x00000007
#define PLLODIV_MASK 0x00000007
#define CUROSC_MASK 0x00000007
#define PLLMUL_MASK 0x0000007F
#define FRCDIV_MASK 0x00000007
/* PBCLK */
#define PBDIV_MASK 0x00000007
/* SYSCLK MUX */
#define SCLK_SRC_FRC1 0
#define SCLK_SRC_SPLL 1
#define SCLK_SRC_POSC 2
#define SCLK_SRC_FRC2 7
/* Reference Oscillator Control Reg fields */
#define REFO_SEL_MASK 0x0f
#define REFO_SEL_SHIFT 0
#define REFO_ACTIVE BIT(8)
#define REFO_DIVSW_EN BIT(9)
#define REFO_OE BIT(12)
#define REFO_ON BIT(15)
#define REFO_DIV_SHIFT 16
#define REFO_DIV_MASK 0x7fff
/* Reference Oscillator Trim Register Fields */
#define REFO_TRIM_REG 0x10
#define REFO_TRIM_MASK 0x1ff
#define REFO_TRIM_SHIFT 23
#define REFO_TRIM_MAX 511
#define ROCLK_SRC_SCLK 0x0
#define ROCLK_SRC_SPLL 0x7
#define ROCLK_SRC_ROCLKI 0x8
/* Memory PLL */
#define MPLL_IDIV 0x3f
#define MPLL_MULT 0xff
#define MPLL_ODIV1 0x7
#define MPLL_ODIV2 0x7
#define MPLL_VREG_RDY BIT(23)
#define MPLL_RDY BIT(31)
#define MPLL_IDIV_SHIFT 0
#define MPLL_MULT_SHIFT 8
#define MPLL_ODIV1_SHIFT 24
#define MPLL_ODIV2_SHIFT 27
#define MPLL_IDIV_INIT 0x03
#define MPLL_MULT_INIT 0x32
#define MPLL_ODIV1_INIT 0x02
#define MPLL_ODIV2_INIT 0x01
struct pic32_clk_priv {
void __iomem *iobase;
void __iomem *syscfg_base;
};
static ulong pic32_get_pll_rate(struct pic32_clk_priv *priv)
{
u32 iclk, idiv, odiv, mult;
ulong plliclk, v;
v = readl(priv->iobase + SPLLCON);
iclk = (v & ICLK_MASK);
idiv = ((v >> 8) & PLLIDIV_MASK) + 1;
odiv = ((v >> 24) & PLLODIV_MASK);
mult = ((v >> 16) & PLLMUL_MASK) + 1;
plliclk = iclk ? SYS_FRC_CLK_HZ : SYS_POSC_CLK_HZ;
if (odiv < 2)
odiv = 2;
else if (odiv < 5)
odiv = (1 << odiv);
else
odiv = 32;
return ((plliclk / idiv) * mult) / odiv;
}
static ulong pic32_get_sysclk(struct pic32_clk_priv *priv)
{
ulong v;
ulong hz;
ulong div, frcdiv;
ulong curr_osc;
/* get clk source */
v = readl(priv->iobase + OSCCON);
curr_osc = (v >> 12) & CUROSC_MASK;
switch (curr_osc) {
case SCLK_SRC_FRC1:
case SCLK_SRC_FRC2:
frcdiv = ((v >> 24) & FRCDIV_MASK);
div = ((1 << frcdiv) + 1) + (128 * (frcdiv == 7));
hz = SYS_FRC_CLK_HZ / div;
break;
case SCLK_SRC_SPLL:
hz = pic32_get_pll_rate(priv);
break;
case SCLK_SRC_POSC:
hz = SYS_POSC_CLK_HZ;
break;
default:
hz = 0;
printf("clk: unknown sclk_src.\n");
break;
}
return hz;
}
static ulong pic32_get_pbclk(struct pic32_clk_priv *priv, int periph)
{
void __iomem *reg;
ulong div, clk_freq;
WARN_ON((periph < PB1CLK) || (periph > PB7CLK));
clk_freq = pic32_get_sysclk(priv);
reg = priv->iobase + PB1DIV + (periph - PB1CLK) * 0x10;
div = (readl(reg) & PBDIV_MASK) + 1;
return clk_freq / div;
}
static ulong pic32_get_cpuclk(struct pic32_clk_priv *priv)
{
return pic32_get_pbclk(priv, PB7CLK);
}
static ulong pic32_set_refclk(struct pic32_clk_priv *priv, int periph,
int parent_rate, int rate, int parent_id)
{
void __iomem *reg;
u32 div, trim, v;
u64 frac;
WARN_ON((periph < REF1CLK) || (periph > REF5CLK));
/* calculate dividers,
* rate = parent_rate / [2 * (div + (trim / 512))]
*/
if (parent_rate <= rate) {
div = 0;
trim = 0;
} else {
div = parent_rate / (rate << 1);
frac = parent_rate;
frac <<= 8;
do_div(frac, rate);
frac -= (u64)(div << 9);
trim = (frac >= REFO_TRIM_MAX) ? REFO_TRIM_MAX : (u32)frac;
}
reg = priv->iobase + REFO1CON + (periph - REF1CLK) * 0x20;
/* disable clk */
writel(REFO_ON | REFO_OE, reg + _CLR_OFFSET);
/* wait till previous src change is active */
wait_for_bit(__func__, reg, REFO_DIVSW_EN | REFO_ACTIVE,
false, CONFIG_SYS_HZ, false);
/* parent_id */
v = readl(reg);
v &= ~(REFO_SEL_MASK << REFO_SEL_SHIFT);
v |= (parent_id << REFO_SEL_SHIFT);
/* apply rodiv */
v &= ~(REFO_DIV_MASK << REFO_DIV_SHIFT);
v |= (div << REFO_DIV_SHIFT);
writel(v, reg);
/* apply trim */
v = readl(reg + REFO_TRIM_REG);
v &= ~(REFO_TRIM_MASK << REFO_TRIM_SHIFT);
v |= (trim << REFO_TRIM_SHIFT);
writel(v, reg + REFO_TRIM_REG);
/* enable clk */
writel(REFO_ON | REFO_OE, reg + _SET_OFFSET);
/* switch divider */
writel(REFO_DIVSW_EN, reg + _SET_OFFSET);
/* wait for divider switching to complete */
return wait_for_bit(__func__, reg, REFO_DIVSW_EN, false,
CONFIG_SYS_HZ, false);
}
static ulong pic32_get_refclk(struct pic32_clk_priv *priv, int periph)
{
u32 rodiv, rotrim, rosel, v, parent_rate;
void __iomem *reg;
u64 rate64;
WARN_ON((periph < REF1CLK) || (periph > REF5CLK));
reg = priv->iobase + REFO1CON + (periph - REF1CLK) * 0x20;
v = readl(reg);
/* get rosel */
rosel = (v >> REFO_SEL_SHIFT) & REFO_SEL_MASK;
/* get div */
rodiv = (v >> REFO_DIV_SHIFT) & REFO_DIV_MASK;
/* get trim */
v = readl(reg + REFO_TRIM_REG);
rotrim = (v >> REFO_TRIM_SHIFT) & REFO_TRIM_MASK;
if (!rodiv)
return 0;
/* get parent rate */
switch (rosel) {
case ROCLK_SRC_SCLK:
parent_rate = pic32_get_cpuclk(priv);
break;
case ROCLK_SRC_SPLL:
parent_rate = pic32_get_pll_rate(priv);
break;
default:
parent_rate = 0;
break;
}
/* Calculation
* rate = parent_rate / [2 * (div + (trim / 512))]
*/
if (rotrim) {
rodiv <<= 9;
rodiv += rotrim;
rate64 = parent_rate;
rate64 <<= 8;
do_div(rate64, rodiv);
v = (u32)rate64;
} else {
v = parent_rate / (rodiv << 1);
}
return v;
}
static ulong pic32_get_mpll_rate(struct pic32_clk_priv *priv)
{
u32 v, idiv, mul;
u32 odiv1, odiv2;
u64 rate;
v = readl(priv->syscfg_base + CFGMPLL);
idiv = v & MPLL_IDIV;
mul = (v >> MPLL_MULT_SHIFT) & MPLL_MULT;
odiv1 = (v >> MPLL_ODIV1_SHIFT) & MPLL_ODIV1;
odiv2 = (v >> MPLL_ODIV2_SHIFT) & MPLL_ODIV2;
rate = (SYS_POSC_CLK_HZ / idiv) * mul;
do_div(rate, odiv1);
do_div(rate, odiv2);
return (ulong)rate;
}
static int pic32_mpll_init(struct pic32_clk_priv *priv)
{
u32 v, mask;
/* initialize */
v = (MPLL_IDIV_INIT << MPLL_IDIV_SHIFT) |
(MPLL_MULT_INIT << MPLL_MULT_SHIFT) |
(MPLL_ODIV1_INIT << MPLL_ODIV1_SHIFT) |
(MPLL_ODIV2_INIT << MPLL_ODIV2_SHIFT);
writel(v, priv->syscfg_base + CFGMPLL);
/* Wait for ready */
mask = MPLL_RDY | MPLL_VREG_RDY;
return wait_for_bit(__func__, priv->syscfg_base + CFGMPLL, mask,
true, get_tbclk(), false);
}
static void pic32_clk_init(struct udevice *dev)
{
const void *blob = gd->fdt_blob;
struct pic32_clk_priv *priv;
ulong rate, pll_hz;
char propname[50];
int i;
priv = dev_get_priv(dev);
pll_hz = pic32_get_pll_rate(priv);
/* Initialize REFOs as not initialized and enabled on reset. */
for (i = REF1CLK; i <= REF5CLK; i++) {
snprintf(propname, sizeof(propname),
"microchip,refo%d-frequency", i - REF1CLK + 1);
rate = fdtdec_get_int(blob, dev->of_offset, propname, 0);
if (rate)
pic32_set_refclk(priv, i, pll_hz, rate, ROCLK_SRC_SPLL);
}
/* Memory PLL */
pic32_mpll_init(priv);
}
static ulong pic32_clk_get_rate(struct udevice *dev)
{
struct pic32_clk_priv *priv = dev_get_priv(dev);
return pic32_get_cpuclk(priv);
}
static ulong pic32_get_periph_rate(struct udevice *dev, int periph)
{
struct pic32_clk_priv *priv = dev_get_priv(dev);
ulong rate;
switch (periph) {
case PB1CLK ... PB7CLK:
rate = pic32_get_pbclk(priv, periph);
break;
case REF1CLK ... REF5CLK:
rate = pic32_get_refclk(priv, periph);
break;
case PLLCLK:
rate = pic32_get_pll_rate(priv);
break;
case MPLL:
rate = pic32_get_mpll_rate(priv);
break;
default:
rate = 0;
break;
}
return rate;
}
static ulong pic32_set_periph_rate(struct udevice *dev, int periph, ulong rate)
{
struct pic32_clk_priv *priv = dev_get_priv(dev);
ulong pll_hz;
switch (periph) {
case REF1CLK ... REF5CLK:
pll_hz = pic32_get_pll_rate(priv);
pic32_set_refclk(priv, periph, pll_hz, rate, ROCLK_SRC_SPLL);
break;
default:
break;
}
return rate;
}
static struct clk_ops pic32_pic32_clk_ops = {
.get_rate = pic32_clk_get_rate,
.set_periph_rate = pic32_set_periph_rate,
.get_periph_rate = pic32_get_periph_rate,
};
static int pic32_clk_probe(struct udevice *dev)
{
struct pic32_clk_priv *priv = dev_get_priv(dev);
fdt_addr_t addr;
fdt_size_t size;
addr = fdtdec_get_addr_size(gd->fdt_blob, dev->of_offset, "reg", &size);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
priv->iobase = ioremap(addr, size);
if (!priv->iobase)
return -EINVAL;
priv->syscfg_base = pic32_get_syscfg_base();
/* initialize clocks */
pic32_clk_init(dev);
return 0;
}
static const struct udevice_id pic32_clk_ids[] = {
{ .compatible = "microchip,pic32mzda-clk"},
{}
};
U_BOOT_DRIVER(pic32_clk) = {
.name = "pic32_clk",
.id = UCLASS_CLK,
.of_match = pic32_clk_ids,
.flags = DM_FLAG_PRE_RELOC,
.ops = &pic32_pic32_clk_ops,
.probe = pic32_clk_probe,
.priv_auto_alloc_size = sizeof(struct pic32_clk_priv),
};
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