[U-Boot,v3,03/14] 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>

---

Changes in v3:
- rename clk-pic32.c to clk_pic32.c
- update clock binding documentation
- replace pic32_ioremap() with ioremap()
- separate MPLL initialization constants

Changes in v2:
- add mpll get clock rate

 .../clock/microchip,pic32-clock.txt                |  33 ++
 drivers/clk/Makefile                               |   1 +
 drivers/clk/clk_pic32.c                            | 433 +++++++++++++++++++++
 include/dt-bindings/clock/microchip,clock.h        |  29 ++
 4 files changed, 496 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

Am Dienstag, den 12.01.2016, 15:48 +0530 schrieb Purna Chandra Mandal:
> 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>

nits below

> 
> ---
> 
> Changes in v3:
> - rename clk-pic32.c to clk_pic32.c
> - update clock binding documentation
> - replace pic32_ioremap() with ioremap()
> - separate MPLL initialization constants
> 
> Changes in v2:
> - add mpll get clock rate
> 
>  .../clock/microchip,pic32-clock.txt                |  33 ++
>  drivers/clk/Makefile                               |   1 +
>  drivers/clk/clk_pic32.c                            | 433
> +++++++++++++++++++++
>  include/dt-bindings/clock/microchip,clock.h        |  29 ++
>  4 files changed, 496 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..02e5ce4
> --- /dev/null
> +++ b/doc/device-tree-bindings/clock/microchip,pic32-clock.txt
> @@ -0,0 +1,33 @@
> +* Microchip PIC32 Clock and Oscillator
> +
> +Microchip PIC32 clock tree consists of few oscillators, PLLs,
> +multiplexers and few divider modules capable of supplying clocks
> +to various controllers within SoC and also to off-chip.
> +
> +PIC32 clock controller output is defined by indices as defined
> +in [0]
> +
> +[0] include/dt-bindings/clock/microchip,clock.h
> +
> +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@1f801200 {
> +		compatible = "microchip,pic32mzda_clk";
> +		reg = <0x1f801200 0x1000>;
> +	};
> +
> +Example: UART controller node that consumes the clock generated by
> the clock
> +controller:
> +
> +	uart1: serial@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..adda769 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..bb0a1cf
> --- /dev/null
> +++ b/drivers/clk/clk_pic32.c
> @@ -0,0 +1,433 @@
> +/*
> + * 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;

you can drop this check. ioremap() always returns a mapped address

> +
> +	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),
> +};
> 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@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 */

On Tue, Jan 12, 2016 at 03:48:18PM +0530, Purna Chandra Mandal wrote:

> PIC32 clock module consists of multiple oscillators, PLLs, mutiplexers
> and dividers capable of supplying clock to various controllers
> on or off-chip.
[snip]
>  include/dt-bindings/clock/microchip,clock.h        |  29 ++

Has this been submitted for the kernel and reviewed there as well
already?  Thanks!

On 01/13/2016 07:08 PM, Daniel Schwierzeck wrote:

> Am Dienstag, den 12.01.2016, 15:48 +0530 schrieb Purna Chandra Mandal:
>> 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>
>
> nits below
>
>> ---
>>
>> Changes in v3:
>> - rename clk-pic32.c to clk_pic32.c
>> - update clock binding documentation
>> - replace pic32_ioremap() with ioremap()
>> - separate MPLL initialization constants
>>
>> Changes in v2:
>> - add mpll get clock rate
>>
>>  .../clock/microchip,pic32-clock.txt                |  33 ++
>>  drivers/clk/Makefile                               |   1 +
>>  drivers/clk/clk_pic32.c                            | 433
>> +++++++++++++++++++++
>>  include/dt-bindings/clock/microchip,clock.h        |  29 ++
>>  4 files changed, 496 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..02e5ce4
>> --- /dev/null
>> +++ b/doc/device-tree-bindings/clock/microchip,pic32-clock.txt
>> @@ -0,0 +1,33 @@
>> +* Microchip PIC32 Clock and Oscillator
>> +
>> +Microchip PIC32 clock tree consists of few oscillators, PLLs,
>> +multiplexers and few divider modules capable of supplying clocks
>> +to various controllers within SoC and also to off-chip.
>> +
>> +PIC32 clock controller output is defined by indices as defined
>> +in [0]
>> +
>> +[0] include/dt-bindings/clock/microchip,clock.h
>> +
>> +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@1f801200 {
>> +		compatible = "microchip,pic32mzda_clk";
>> +		reg = <0x1f801200 0x1000>;
>> +	};
>> +
>> +Example: UART controller node that consumes the clock generated by
>> the clock
>> +controller:
>> +
>> +	uart1: serial@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..adda769 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..bb0a1cf
>> --- /dev/null
>> +++ b/drivers/clk/clk_pic32.c
>> @@ -0,0 +1,433 @@
>> +/*
>> + * Copyright (C) 2015 Purna Chandra Mandal <
>> purna.mandal@microchip.com>
>> + *
>> + * SPDX-License-Identifier:	GPL-2.0+
>> + *
>> + */
>> +
>> [...]
>> +
>> +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;
> you can drop this check. ioremap() always returns a mapped address

ack. Will drop.

>> +
>> +	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),
>> +};
>> 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@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 */

On 01/13/2016 08:25 PM, Tom Rini wrote:

> On Tue, Jan 12, 2016 at 03:48:18PM +0530, Purna Chandra Mandal wrote:
>
>> PIC32 clock module consists of multiple oscillators, PLLs, mutiplexers
>> and dividers capable of supplying clock to various controllers
>> on or off-chip.
> [snip]
>>  include/dt-bindings/clock/microchip,clock.h        |  29 ++
> Has this been submitted for the kernel and reviewed there as well
> already?  Thanks!
>
Clock driver in kernel is under review.
[1] clock driver: https://lkml.org/lkml/2016/1/7/764
[0] clock binding: https://lkml.org/lkml/2016/1/7/762
 
Please note clock driver in Linux kernel is implemented in more elaborate/descriptive way - all the sub-modules are individually defined in device-tree (having "#clock-cells = <0>") and their phandles are directly
referred in clock clients so there was no need of having dt-binding header.

On Thu, Jan 14, 2016 at 11:34:27AM +0530, Purna Chandra Mandal wrote:
> On 01/13/2016 08:25 PM, Tom Rini wrote:
> 
> > On Tue, Jan 12, 2016 at 03:48:18PM +0530, Purna Chandra Mandal wrote:
> >
> >> PIC32 clock module consists of multiple oscillators, PLLs, mutiplexers
> >> and dividers capable of supplying clock to various controllers
> >> on or off-chip.
> > [snip]
> >>  include/dt-bindings/clock/microchip,clock.h        |  29 ++
> > Has this been submitted for the kernel and reviewed there as well
> > already?  Thanks!
> >
> Clock driver in kernel is under review.
> [1] clock driver: https://lkml.org/lkml/2016/1/7/764
> [0] clock binding: https://lkml.org/lkml/2016/1/7/762
>  
> Please note clock driver in Linux kernel is implemented in more elaborate/descriptive way - all the sub-modules are individually defined in device-tree (having "#clock-cells = <0>") and their phandles are directly
> referred in clock clients so there was no need of having dt-binding header.

Note that we really must have the same DT functional in both cases.  So
it's fine to have extra nodes that U-Boot doesn't use.