[U-Boot] [PATCH v2 02/13] drivers: clk: Add clock driver for Microchip PIC32 Microcontroller.
Purna Chandra Mandal
purna.mandal at microchip.com
Tue Jan 12 05:55:57 CET 2016
On 01/11/2016 09:46 PM, Daniel Schwierzeck wrote:
> Am Montag, den 04.01.2016, 19:30 +0530 schrieb Purna Chandra Mandal:
>> Signed-off-by: Purna Chandra Mandal <purna.mandal at microchip.com>
>>
>> ---
>>
>> Changes in v2:
>> - add get clock rate for mpll clock
>>
>> .../clock/microchip,pic32-clock.txt | 28 ++
>> drivers/clk/Makefile | 1 +
>> drivers/clk/clk-pic32.c | 427
>> +++++++++++++++++++++
>> include/dt-bindings/clock/microchip,clock.h | 29 ++
>> 4 files changed, 485 insertions(+)
>> create mode 100644 doc/device-tree-bindings/clock/microchip,pic32
>> -clock.txt
>> create mode 100644 drivers/clk/clk-pic32.c
>> create mode 100644 include/dt-bindings/clock/microchip,clock.h
>>
>> diff --git a/doc/device-tree-bindings/clock/microchip,pic32-clock.txt
>> b/doc/device-tree-bindings/clock/microchip,pic32-clock.txt
>> new file mode 100644
>> index 0000000..d02b9d7
>> --- /dev/null
>> +++ b/doc/device-tree-bindings/clock/microchip,pic32-clock.txt
>> @@ -0,0 +1,28 @@
>> +* Microchip PIC32 Clock and Oscillator
>> +
>> +The PIC32 clock controller generates and supplies clock to various
>> +controllers within the SoC.
>> +
>> +Required Properties:
>> +
>> +- compatible: should be "microchip,pic32mzda_clk"
>> +- reg: physical base address of the controller and length of memory
>> mapped
>> + region.
>> +- #clock-cells: should be 1.
>> +
>> +Example: Clock controller node:
>> +
>> + clock: clk at 1f801200 {
>> + compatible = "microchip,pic32mzda_clk";
>> + reg = <0xbf801200 0x1000>;
>> + };
>> +
>> +Example: UART controller node that consumes the clock generated by
>> the clock
>> + controller:
>> +
>> + uart1: serial at 1f822000 {
>> + compatible = "microchip,pic32mzda-uart";
>> + reg = <0xbf822000 0x50>;
>> + interrupts = <112 IRQ_TYPE_LEVEL_HIGH>;
>> + clocks = <&clock PB2CLK>;
>> + };
>> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
>> index 4a6a4a8..3c84e08 100644
>> --- a/drivers/clk/Makefile
>> +++ b/drivers/clk/Makefile
>> @@ -9,3 +9,4 @@ obj-$(CONFIG_CLK) += clk-uclass.o
>> obj-$(CONFIG_ROCKCHIP_RK3036) += clk_rk3036.o
>> obj-$(CONFIG_ROCKCHIP_RK3288) += clk_rk3288.o
>> obj-$(CONFIG_SANDBOX) += clk_sandbox.o
>> +obj-$(CONFIG_MACH_PIC32) += clk-pic32.o
>> diff --git a/drivers/clk/clk-pic32.c b/drivers/clk/clk-pic32.c
>> new file mode 100644
>> index 0000000..70aac05
>> --- /dev/null
>> +++ b/drivers/clk/clk-pic32.c
>> @@ -0,0 +1,427 @@
>> +/*
>> + * Copyright (C) 2015 Purna Chandra Mandal <
>> purna.mandal at microchip.com>
>> + *
>> + * SPDX-License-Identifier: GPL-2.0+
>> + *
>> + */
>> +
>> +#include <common.h>
>> +#include <dm.h>
>> +#include <clk.h>
>> +#include <div64.h>
>> +#include <wait_bit.h>
> I can't find wait_bit.h in mainline. Is there an unmerged patch which
> adds this file and you depend on? Could you point me to it? Thanks.
Yes, this is not on mainline. Based on review (from Marek Vesut)
to use wait_for_bit() for unbounded loops I have pulled the
under-review patch from [1].
[1] http://patchwork.ozlabs.org/patch/561185/
>> +#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
>> +
>> +/* PLL */
>> +#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 0x03
>> +#define MPLL_MULT 0x32
>> +#define MPLL_ODIV1 0x02
>> +#define MPLL_ODIV2 0x01
>> +#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
>> +
>> +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 */
>> + wait_for_bit(__func__, reg, REFO_DIVSW_EN, false,
>> + CONFIG_SYS_HZ, false);
>> +
>> + return 0;
>> +}
>> +
>> +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 & 0x3f;
>> + mul = (v >> MPLL_MULT_SHIFT) & 0xff;
>> + odiv1 = (v >> MPLL_ODIV1_SHIFT) & 0x7;
>> + odiv2 = (v >> MPLL_ODIV2_SHIFT) & 0x7;
>> +
>> + rate = (SYS_POSC_CLK_HZ / idiv) * mul;
>> + do_div(rate, odiv1);
>> + do_div(rate, odiv2);
>> +
>> + return (ulong)rate;
>> +}
>> +
>> +static void pic32_mpll_init(struct pic32_clk_priv *priv)
>> +{
>> + u32 v, mask;
>> +
>> + /* initialize */
>> + v = (MPLL_IDIV << MPLL_IDIV_SHIFT) |
>> + (MPLL_MULT << MPLL_MULT_SHIFT) |
>> + (MPLL_ODIV1 << MPLL_ODIV1_SHIFT) |
>> + (MPLL_ODIV2 << MPLL_ODIV2_SHIFT);
>> +
>> + writel(v, priv->syscfg_base + CFGMPLL);
>> +
>> + /* Wait for ready */
>> + mask = MPLL_RDY | MPLL_VREG_RDY;
>> + 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;
>> +
>> + addr = dev_get_addr(dev);
>> + if (addr == FDT_ADDR_T_NONE)
>> + return -EINVAL;
>> +
>> + priv->iobase = pic32_ioremap(addr);
>> + priv->syscfg_base = pic32_ioremap(PIC32_CFG_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),
>> +};
>> diff --git a/include/dt-bindings/clock/microchip,clock.h b/include/dt
>> -bindings/clock/microchip,clock.h
>> new file mode 100644
>> index 0000000..93c222d
>> --- /dev/null
>> +++ b/include/dt-bindings/clock/microchip,clock.h
>> @@ -0,0 +1,29 @@
>> +/*
>> + * (c) 2015 Purna Chandra Mandal <purna.mandal at microchip.com>
>> + *
>> + * SPDX-License-Identifier: GPL-2.0+
>> + *
>> + */
>> +
>> +#ifndef __CLK_MICROCHIP_PIC32
>> +#define __CLK_MICROCHIP_PIC32
>> +
>> +/* clock output indices */
>> +#define BASECLK 0
>> +#define PLLCLK 1
>> +#define MPLL 2
>> +#define SYSCLK 3
>> +#define PB1CLK 4
>> +#define PB2CLK 5
>> +#define PB3CLK 6
>> +#define PB4CLK 7
>> +#define PB5CLK 8
>> +#define PB6CLK 9
>> +#define PB7CLK 10
>> +#define REF1CLK 11
>> +#define REF2CLK 12
>> +#define REF3CLK 13
>> +#define REF4CLK 14
>> +#define REF5CLK 15
>> +
>> +#endif /* __CLK_MICROCHIP_PIC32 */
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