[PATCH V3] clk: clk_versaclock: Add support for versaclock driver

Sean Anderson sean.anderson at seco.com
Fri Jun 4 18:17:27 CEST 2021



On 6/4/21 11:56 AM, Adam Ford wrote:
> On Fri, Jun 4, 2021 at 9:29 AM Sean Anderson <sean.anderson at seco.com> wrote:
>>
>>
>>
>> On 6/4/21 10:22 AM, Adam Ford wrote:
>>   > The driver is based on the Versaclock driver from the Linux code, but
>>   > due differences in the clock API between them, some pieces had to be
>>   > changed.
>>   >
>>   > This driver creates a mux, pfd, pll, and a series of fod ouputs.
>>   >   Rate               Usecnt      Name
>>   > ------------------------------------------
>>   >   25000000             0        `-- x304-clock
>>   >   25000000             0            `-- clock-controller at 6a.mux
>>   >   25000000             0                |-- clock-controller at 6a.pfd
>>   >   2800000000           0                |   `-- clock-controller at 6a.pll
>>   >   33333333             0                |       |-- clock-controller at 6a.fod0
>>   >   33333333             0                |       |   `-- clock-controller at 6a.out1
>>   >   33333333             0                |       |-- clock-controller at 6a.fod1
>>   >   33333333             0                |       |   `-- clock-controller at 6a.out2
>>   >   50000000             0                |       |-- clock-controller at 6a.fod2
>>   >   50000000             0                |       |   `-- clock-controller at 6a.out3
>>   >   125000000            0                |       `-- clock-controller at 6a.fod3
>>   >   125000000            0                |           `-- clock-controller at 6a.out4
>>   >   25000000             0                `-- clock-controller at 6a.out0_sel_i2cb
>>   >
>>   > A translation function is added so the references to <&versaclock X> get routed
>>   > to the corresponding clock-controller at 6a.outX.
>>   >
>>   > Signed-off-by: Adam Ford <aford173 at gmail.com>
>>   > ---
>>   > V3:  Streamline finding the out OUTx subnodes.
>>   >       Add error handling.
>>   >       Replace printf and pr_err with dev_dbg.
>>   >       Restore registers removed in V2.
>>   >
>>   > V2:  Remove unused registers.
>>   >       Fix spacing in Makefile.
>>   >       Make the versaclock driver dependent on CCF.
>>   >       Move the versaclock_ids next to U_BOOT_DRIVER(versaclock)
>>   >
>>   > diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
>>   > index 40a5a5dd88..2a7507ea18 100644
>>   > --- a/drivers/clk/Kconfig
>>   > +++ b/drivers/clk/Kconfig
>>   > @@ -197,4 +197,13 @@ config SANDBOX_CLK_CCF
>>   >        Enable this option if you want to test the Linux kernel's Common
>>   >        Clock Framework [CCF] code in U-Boot's Sandbox clock driver.
>>   >
>>   > +config CLK_VERSACLOCK
>>   > +    tristate "Enable VersaClock 5/6 devices"
>>   > +    depends on CLK
>>   > +    depends on CLK_CCF
>>   > +    depends on OF_CONTROL
>>   > +    help
>>   > +      This driver supports the IDT VersaClock 5 and VersaClock 6
>>   > +      programmable clock generators.
>>   > +
>>   >   endmenu
>>   > diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
>>   > index 645709b855..6f5ddafd64 100644
>>   > --- a/drivers/clk/Makefile
>>   > +++ b/drivers/clk/Makefile
>>   > @@ -51,3 +51,4 @@ obj-$(CONFIG_SANDBOX_CLK_CCF) += clk_sandbox_ccf.o
>>   >   obj-$(CONFIG_STM32H7) += clk_stm32h7.o
>>   >   obj-$(CONFIG_CLK_VERSAL) += clk_versal.o
>>   >   obj-$(CONFIG_CLK_CDCE9XX) += clk-cdce9xx.o
>>   > +obj-$(CONFIG_CLK_VERSACLOCK) += clk_versaclock.o
>>   > diff --git a/drivers/clk/clk_versaclock.c b/drivers/clk/clk_versaclock.c
>>   > new file mode 100644
>>   > index 0000000000..84893d842c
>>   > --- /dev/null
>>   > +++ b/drivers/clk/clk_versaclock.c
>>   > @@ -0,0 +1,1099 @@
>>   > +// SPDX-License-Identifier: GPL-2.0-or-later
>>   > +/*
>>   > + * Driver for IDT Versaclock 5/6
>>   > + *
>>   > + * Derived from code Copyright (C) 2017 Marek Vasut <marek.vasut at gmail.com>
>>   > + */
>>   > +
>>   > +#include <common.h>
>>   > +#include <clk.h>
>>   > +#include <clk-uclass.h>
>>   > +#include <dm.h>
>>   > +#include <errno.h>
>>   > +#include <i2c.h>
>>   > +#include <dm/device_compat.h>
>>   > +#include <log.h>
>>   > +#include <linux/clk-provider.h>
>>   > +#include <linux/kernel.h>
>>   > +#include <linux/math64.h>
>>   > +
>>   > +#include <dt-bindings/clk/versaclock.h>
>>   > +
>>   > +/* VersaClock5 registers */
>>   > +#define VC5_OTP_CONTROL                             0x00
>>   > +
>>   > +/* Factory-reserved register block */
>>   > +#define VC5_RSVD_DEVICE_ID                  0x01
>>   > +#define VC5_RSVD_ADC_GAIN_7_0                       0x02
>>   > +#define VC5_RSVD_ADC_GAIN_15_8                      0x03
>>   > +#define VC5_RSVD_ADC_OFFSET_7_0                     0x04
>>   > +#define VC5_RSVD_ADC_OFFSET_15_8            0x05
>>   > +#define VC5_RSVD_TEMPY                              0x06
>>   > +#define VC5_RSVD_OFFSET_TBIN                        0x07
>>   > +#define VC5_RSVD_GAIN                               0x08
>>   > +#define VC5_RSVD_TEST_NP                    0x09
>>   > +#define VC5_RSVD_UNUSED                             0x0a
>>   > +#define VC5_RSVD_BANDGAP_TRIM_UP            0x0b
>>   > +#define VC5_RSVD_BANDGAP_TRIM_DN            0x0c
>>   > +#define VC5_RSVD_CLK_R_12_CLK_AMP_4         0x0d
>>   > +#define VC5_RSVD_CLK_R_34_CLK_AMP_4         0x0e
>>   > +#define VC5_RSVD_CLK_AMP_123                        0x0f
>>   > +
>>   > +/* Configuration register block */
>>   > +#define VC5_PRIM_SRC_SHDN                   0x10
>>   > +#define VC5_PRIM_SRC_SHDN_EN_XTAL           BIT(7)
>>   > +#define VC5_PRIM_SRC_SHDN_EN_CLKIN          BIT(6)
>>   > +#define VC5_PRIM_SRC_SHDN_EN_DOUBLE_XTAL_FREQ       BIT(3)
>>   > +#define VC5_PRIM_SRC_SHDN_SP                        BIT(1)
>>   > +#define VC5_PRIM_SRC_SHDN_EN_GBL_SHDN               BIT(0)
>>   > +
>>   > +#define VC5_VCO_BAND                                0x11
>>   > +#define VC5_XTAL_X1_LOAD_CAP                        0x12
>>   > +#define VC5_XTAL_X2_LOAD_CAP                        0x13
>>   > +#define VC5_REF_DIVIDER                             0x15
>>   > +#define VC5_REF_DIVIDER_SEL_PREDIV2         BIT(7)
>>   > +#define VC5_REF_DIVIDER_REF_DIV(n)          ((n) & 0x3f)
>>   > +
>>   > +#define VC5_VCO_CTRL_AND_PREDIV                     0x16
>>   > +#define VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV       BIT(7)
>>   > +
>>   > +#define VC5_FEEDBACK_INT_DIV                        0x17
>>   > +#define VC5_FEEDBACK_INT_DIV_BITS           0x18
>>   > +#define VC5_FEEDBACK_FRAC_DIV(n)            (0x19 + (n))
>>   > +#define VC5_RC_CONTROL0                             0x1e
>>   > +#define VC5_RC_CONTROL1                             0x1f
>>   > +/* Register 0x20 is factory reserved */
>>   > +
>>   > +/* Output divider control for divider 1,2,3,4 */
>>   > +#define VC5_OUT_DIV_CONTROL(idx)    (0x21 + ((idx) * 0x10))
>>   > +#define VC5_OUT_DIV_CONTROL_RESET   BIT(7)
>>   > +#define VC5_OUT_DIV_CONTROL_SELB_NORM       BIT(3)
>>   > +#define VC5_OUT_DIV_CONTROL_SEL_EXT BIT(2)
>>   > +#define VC5_OUT_DIV_CONTROL_INT_MODE        BIT(1)
>>   > +#define VC5_OUT_DIV_CONTROL_EN_FOD  BIT(0)
>>   > +
>>   > +#define VC5_OUT_DIV_FRAC(idx, n)    (0x22 + ((idx) * 0x10) + (n))
>>   > +#define VC5_OUT_DIV_FRAC4_OD_SCEE   BIT(1)
>>   > +
>>   > +#define VC5_OUT_DIV_STEP_SPREAD(idx, n)     (0x26 + ((idx) * 0x10) + (n))
>>   > +#define VC5_OUT_DIV_SPREAD_MOD(idx, n)      (0x29 + ((idx) * 0x10) + (n))
>>   > +#define VC5_OUT_DIV_SKEW_INT(idx, n)        (0x2b + ((idx) * 0x10) + (n))
>>   > +#define VC5_OUT_DIV_INT(idx, n)             (0x2d + ((idx) * 0x10) + (n))
>>   > +#define VC5_OUT_DIV_SKEW_FRAC(idx)  (0x2f + ((idx) * 0x10))
>>   > +/* Registers 0x30, 0x40, 0x50 are factory reserved */
>>   > +
>>   > +/* Clock control register for clock 1,2 */
>>   > +#define VC5_CLK_OUTPUT_CFG(idx, n)  (0x60 + ((idx) * 0x2) + (n))
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_SHIFT       5
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_MASK GENMASK(7, VC5_CLK_OUTPUT_CFG0_CFG_SHIFT)
>>   > +
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_LVPECL      (VC5_LVPECL)
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_CMOS                (VC5_CMOS)
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_HCSL33      (VC5_HCSL33)
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_LVDS                (VC5_LVDS)
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_CMOS2               (VC5_CMOS2)
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_CMOSD               (VC5_CMOSD)
>>   > +#define VC5_CLK_OUTPUT_CFG0_CFG_HCSL25      (VC5_HCSL25)
>>   > +
>>   > +#define VC5_CLK_OUTPUT_CFG0_PWR_SHIFT       3
>>   > +#define VC5_CLK_OUTPUT_CFG0_PWR_MASK GENMASK(4, VC5_CLK_OUTPUT_CFG0_PWR_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_PWR_18  (0 << VC5_CLK_OUTPUT_CFG0_PWR_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_PWR_25  (2 << VC5_CLK_OUTPUT_CFG0_PWR_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_PWR_33  (3 << VC5_CLK_OUTPUT_CFG0_PWR_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_SLEW_SHIFT      0
>>   > +#define VC5_CLK_OUTPUT_CFG0_SLEW_MASK GENMASK(1, VC5_CLK_OUTPUT_CFG0_SLEW_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_SLEW_80 (0 << VC5_CLK_OUTPUT_CFG0_SLEW_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_SLEW_85 (1 << VC5_CLK_OUTPUT_CFG0_SLEW_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_SLEW_90 (2 << VC5_CLK_OUTPUT_CFG0_SLEW_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG0_SLEW_100        (3 << VC5_CLK_OUTPUT_CFG0_SLEW_SHIFT)
>>   > +#define VC5_CLK_OUTPUT_CFG1_EN_CLKBUF       BIT(0)
>>   > +
>>   > +#define VC5_CLK_OE_SHDN                             0x68
>>   > +#define VC5_CLK_OS_SHDN                             0x69
>>   > +
>>   > +#define VC5_GLOBAL_REGISTER                 0x76
>>   > +#define VC5_GLOBAL_REGISTER_GLOBAL_RESET    BIT(5)
>>   > +
>>   > +/* PLL/VCO runs between 2.5 GHz and 3.0 GHz */
>>   > +#define VC5_PLL_VCO_MIN                             2500000000UL
>>   > +#define VC5_PLL_VCO_MAX                             3000000000UL
>>   > +
>>   > +/* VC5 Input mux settings */
>>   > +#define VC5_MUX_IN_XIN              BIT(0)
>>   > +#define VC5_MUX_IN_CLKIN    BIT(1)
>>   > +
>>   > +/* Maximum number of clk_out supported by this driver */
>>   > +#define VC5_MAX_CLK_OUT_NUM 5
>>   > +
>>   > +/* Maximum number of FODs supported by this driver */
>>   > +#define VC5_MAX_FOD_NUM     4
>>   > +
>>   > +/* flags to describe chip features */
>>   > +/* chip has built-in oscilator */
>>   > +#define VC5_HAS_INTERNAL_XTAL       BIT(0)
>>   > +/* chip has PFD requency doubler */
>>   > +#define VC5_HAS_PFD_FREQ_DBL        BIT(1)
>>   > +
>>   > +/* Supported IDT VC5 models. */
>>   > +enum vc5_model {
>>   > +    IDT_VC5_5P49V5923,
>>   > +    IDT_VC5_5P49V5925,
>>   > +    IDT_VC5_5P49V5933,
>>   > +    IDT_VC5_5P49V5935,
>>   > +    IDT_VC6_5P49V6901,
>>   > +    IDT_VC6_5P49V6965,
>>   > +};
>>   > +
>>   > +/* Structure to describe features of a particular VC5 model */
>>   > +struct vc5_chip_info {
>>   > +    const enum vc5_model    model;
>>   > +    const unsigned int      clk_fod_cnt;
>>   > +    const unsigned int      clk_out_cnt;
>>   > +    const u32               flags;
>>   > +};
>>   > +
>>   > +struct vc5_driver_data;
>>   > +
>>   > +struct vc5_hw_data {
>>   > +    struct clk              hw;
>>   > +    struct vc5_driver_data  *vc5;
>>   > +    u32                     div_int;
>>   > +    u32                     div_frc;
>>   > +    unsigned int            num;
>>   > +};
>>   > +
>>   > +struct vc5_out_data {
>>   > +    struct clk              hw;
>>   > +    struct vc5_driver_data  *vc5;
>>   > +    unsigned int            num;
>>   > +    unsigned int            clk_output_cfg0;
>>   > +    unsigned int            clk_output_cfg0_mask;
>>   > +};
>>   > +
>>   > +struct vc5_driver_data {
>>   > +    struct udevice          *i2c;
>>   > +    const struct vc5_chip_info      *chip_info;
>>   > +
>>   > +    struct clk              *pin_xin;
>>   > +    struct clk              *pin_clkin;
>>   > +    unsigned char           clk_mux_ins;
>>   > +    struct clk              clk_mux;
>>   > +    struct clk              clk_mul;
>>   > +    struct clk              clk_pfd;
>>   > +    struct vc5_hw_data      clk_pll;
>>   > +    struct vc5_hw_data      clk_fod[VC5_MAX_FOD_NUM];
>>   > +    struct vc5_out_data     clk_out[VC5_MAX_CLK_OUT_NUM];
>>   > +};
>>   > +
>>   > +static const struct vc5_chip_info idt_5p49v5923_info = {
>>   > +    .model = IDT_VC5_5P49V5923,
>>   > +    .clk_fod_cnt = 2,
>>   > +    .clk_out_cnt = 3,
>>   > +    .flags = 0,
>>   > +};
>>   > +
>>   > +static const struct vc5_chip_info idt_5p49v5925_info = {
>>   > +    .model = IDT_VC5_5P49V5925,
>>   > +    .clk_fod_cnt = 4,
>>   > +    .clk_out_cnt = 5,
>>   > +    .flags = 0,
>>   > +};
>>   > +
>>   > +static const struct vc5_chip_info idt_5p49v5933_info = {
>>   > +    .model = IDT_VC5_5P49V5933,
>>   > +    .clk_fod_cnt = 2,
>>   > +    .clk_out_cnt = 3,
>>   > +    .flags = VC5_HAS_INTERNAL_XTAL,
>>   > +};
>>   > +
>>   > +static const struct vc5_chip_info idt_5p49v5935_info = {
>>   > +    .model = IDT_VC5_5P49V5935,
>>   > +    .clk_fod_cnt = 4,
>>   > +    .clk_out_cnt = 5,
>>   > +    .flags = VC5_HAS_INTERNAL_XTAL,
>>   > +};
>>   > +
>>   > +static const struct vc5_chip_info idt_5p49v6901_info = {
>>   > +    .model = IDT_VC6_5P49V6901,
>>   > +    .clk_fod_cnt = 4,
>>   > +    .clk_out_cnt = 5,
>>   > +    .flags = VC5_HAS_PFD_FREQ_DBL,
>>   > +};
>>   > +
>>   > +static const struct vc5_chip_info idt_5p49v6965_info = {
>>   > +    .model = IDT_VC6_5P49V6965,
>>   > +    .clk_fod_cnt = 4,
>>   > +    .clk_out_cnt = 5,
>>   > +    .flags = 0,
>>   > +};
>>   > +
>>   > +static int vc5_update_bits(struct udevice *dev, unsigned int reg, unsigned int mask,
>>   > +                       unsigned int src)
>>   > +{
>>   > +    int ret;
>>   > +    unsigned char cache;
>>   > +
>>   > +    ret = dm_i2c_read(dev, reg, &cache, 1);
>>   > +    if (ret < 0)
>>   > +            return ret;
>>   > +
>>   > +    cache &= ~mask;
>>   > +    cache |= mask & src;
>>   > +    ret = dm_i2c_write(dev, reg, (uchar *)&cache, 1);
>>   > +
>>   > +    return ret;
>>   > +}
>>   > +
>>   > +static unsigned long vc5_mux_get_rate(struct clk *hw)
>>   > +{
>>   > +    return clk_get_rate(clk_get_parent(hw));
>>   > +}
>>   > +
>>   > +static int vc5_mux_set_parent(struct clk *hw, unsigned char index)
>>   > +{
>>   > +    struct vc5_driver_data *vc5 = container_of(hw, struct vc5_driver_data, clk_mux);
>>   > +    const u8 mask = VC5_PRIM_SRC_SHDN_EN_XTAL | VC5_PRIM_SRC_SHDN_EN_CLKIN;
>>   > +    u8 src;
>>   > +
>>   > +    if (index > 1 || !vc5->clk_mux_ins)
>>   > +            return -EINVAL;
>>   > +
>>   > +    if (vc5->clk_mux_ins == (VC5_MUX_IN_CLKIN | VC5_MUX_IN_XIN)) {
>>   > +            if (index == 0)
>>   > +                    src = VC5_PRIM_SRC_SHDN_EN_XTAL;
>>   > +            if (index == 1)
>>   > +                    src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
>>   > +    } else {
>>   > +            if (index != 0)
>>   > +                    return -EINVAL;
>>   > +
>>   > +            if (vc5->clk_mux_ins == VC5_MUX_IN_XIN)
>>   > +                    src = VC5_PRIM_SRC_SHDN_EN_XTAL;
>>   > +            else if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
>>   > +                    src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
>>   > +            else /* Invalid; should have been caught by vc5_probe() */
>>   > +                    return -EINVAL;
>>   > +    }
>>   > +
>>   > +    return vc5_update_bits(vc5->i2c, VC5_PRIM_SRC_SHDN, mask, src);
>>   > +}
>>   > +
>>   > +static const struct clk_ops vc5_mux_ops = {
>>   > +    .get_rate       = vc5_mux_get_rate,
>>   > +};
>>   > +
>>   > +static unsigned long vc5_pfd_round_rate(struct clk *hw, unsigned long rate)
>>   > +{
>>   > +    struct clk *clk_parent = clk_get_parent(hw);
>>   > +    unsigned long parent_rate = clk_get_rate(clk_parent);
>>   > +    unsigned long idiv;
>>   > +
>>   > +    /* PLL cannot operate with input clock above 50 MHz. */
>>   > +    if (rate > 50000000)
>>   > +            return -EINVAL;
>>   > +
>>   > +    /* CLKIN within range of PLL input, feed directly to PLL. */
>>   > +    if (parent_rate <= 50000000)
>>   > +            return parent_rate;
>>   > +
>>   > +    idiv = DIV_ROUND_UP(parent_rate, rate);
>>   > +    if (idiv > 127)
>>   > +            return -EINVAL;
>>   > +
>>   > +    return parent_rate / idiv;
>>   > +}
>>   > +
>>   > +static unsigned long vc5_pfd_recalc_rate(struct clk *hw)
>>   > +{
>>   > +    struct vc5_driver_data *vc5 =
>>   > +            container_of(hw, struct vc5_driver_data, clk_pfd);
>>   > +    unsigned int prediv, div;
>>   > +    struct clk *clk_parent = clk_get_parent(hw);
>>   > +    unsigned long parent_rate = clk_get_rate(clk_parent);
>>   > +
>>   > +    dm_i2c_read(vc5->i2c, VC5_VCO_CTRL_AND_PREDIV, (uchar *)&prediv, 1);
>>   > +
>>   > +    /* The bypass_prediv is set, PLL fed from Ref_in directly. */
>>   > +    if (prediv & VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV)
>>   > +            return parent_rate;
>>   > +
>>   > +    dm_i2c_read(vc5->i2c, VC5_REF_DIVIDER, (uchar *)&div, 1);
>>   > +
>>   > +    /* The Sel_prediv2 is set, PLL fed from prediv2 (Ref_in / 2) */
>>   > +    if (div & VC5_REF_DIVIDER_SEL_PREDIV2)
>>   > +            return parent_rate / 2;
>>   > +    else
>>   > +            return parent_rate / VC5_REF_DIVIDER_REF_DIV(div);
>>   > +}
>>   > +
>>   > +static unsigned long vc5_pfd_set_rate(struct clk *hw, unsigned long rate)
>>   > +{
>>   > +    struct vc5_driver_data *vc5 =
>>   > +            container_of(hw, struct vc5_driver_data, clk_pfd);
>>   > +    unsigned long idiv;
>>   > +    u8 div;
>>   > +    struct clk *clk_parent = clk_get_parent(hw);
>>   > +    unsigned long parent_rate = clk_get_rate(clk_parent);
>>   > +
>>   > +    /* CLKIN within range of PLL input, feed directly to PLL. */
>>   > +    if (parent_rate <= 50000000) {
>>   > +            vc5_update_bits(vc5->i2c, VC5_VCO_CTRL_AND_PREDIV,
>>   > +                            VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV,
>>   > +                            VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV);
>>   > +            vc5_update_bits(vc5->i2c, VC5_REF_DIVIDER, 0xff, 0x00);
>>   > +            return 0;
>>   > +    }
>>   > +
>>   > +    idiv = DIV_ROUND_UP(parent_rate, rate);
>>   > +
>>   > +    /* We have dedicated div-2 predivider. */
>>   > +    if (idiv == 2)
>>   > +            div = VC5_REF_DIVIDER_SEL_PREDIV2;
>>   > +    else
>>   > +            div = VC5_REF_DIVIDER_REF_DIV(idiv);
>>   > +
>>   > +    vc5_update_bits(vc5->i2c, VC5_REF_DIVIDER, 0xff, div);
>>   > +    vc5_update_bits(vc5->i2c, VC5_VCO_CTRL_AND_PREDIV,
>>   > +                    VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV, 0);
>>   > +
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static const struct clk_ops vc5_pfd_ops = {
>>   > +    .round_rate     = vc5_pfd_round_rate,
>>   > +    .get_rate       = vc5_pfd_recalc_rate,
>>   > +    .set_rate       = vc5_pfd_set_rate,
>>   > +};
>>   > +
>>   > +/*
>>   > + * VersaClock5 PLL/VCO
>>   > + */
>>   > +static unsigned long vc5_pll_recalc_rate(struct clk *hw)
>>   > +{
>>   > +    struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
>>   > +    struct vc5_driver_data *vc = hwdata->vc5;
>>   > +    struct clk *clk_parent = clk_get_parent(hw);
>>   > +    unsigned long parent_rate = clk_get_rate(clk_parent);
>>   > +    u32 div_int, div_frc;
>>   > +    u8 fb[5];
>>   > +
>>   > +    dm_i2c_read(vc->i2c, VC5_FEEDBACK_INT_DIV, fb, 5);
>>   > +
>>   > +    div_int = (fb[0] << 4) | (fb[1] >> 4);
>>   > +    div_frc = (fb[2] << 16) | (fb[3] << 8) | fb[4];
>>   > +
>>   > +    /* The PLL divider has 12 integer bits and 24 fractional bits */
>>   > +    return (parent_rate * div_int) + ((parent_rate * div_frc) >> 24);
>>   > +}
>>   > +
>>   > +static unsigned long vc5_pll_round_rate(struct clk *hw, unsigned long rate)
>>   > +{
>>   > +    struct clk *clk_parent = clk_get_parent(hw);
>>   > +    unsigned long parent_rate = clk_get_rate(clk_parent);
>>   > +    struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
>>   > +    u32 div_int;
>>   > +    u64 div_frc;
>>   > +
>>   > +    if (rate < VC5_PLL_VCO_MIN)
>>   > +            rate = VC5_PLL_VCO_MIN;
>>   > +    if (rate > VC5_PLL_VCO_MAX)
>>   > +            rate = VC5_PLL_VCO_MAX;
>>   > +
>>   > +    /* Determine integer part, which is 12 bit wide */
>>   > +    div_int = rate / parent_rate;
>>   > +    if (div_int > 0xfff)
>>   > +            rate = parent_rate * 0xfff;
>>   > +
>>   > +    /* Determine best fractional part, which is 24 bit wide */
>>   > +    div_frc = rate % parent_rate;
>>   > +    div_frc *= BIT(24) - 1;
>>   > +    do_div(div_frc, parent_rate);
>>   > +
>>   > +    hwdata->div_int = div_int;
>>   > +    hwdata->div_frc = (u32)div_frc;
>>   > +
>>   > +    return (parent_rate * div_int) + ((parent_rate * div_frc) >> 24);
>>   > +}
>>   > +
>>   > +static unsigned long vc5_pll_set_rate(struct clk *hw, unsigned long rate)
>>   > +{
>>   > +    struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
>>   > +    struct vc5_driver_data *vc5 = hwdata->vc5;
>>   > +    u8 fb[5];
>>   > +
>>   > +    fb[0] = hwdata->div_int >> 4;
>>   > +    fb[1] = hwdata->div_int << 4;
>>   > +    fb[2] = hwdata->div_frc >> 16;
>>   > +    fb[3] = hwdata->div_frc >> 8;
>>   > +    fb[4] = hwdata->div_frc;
>>   > +
>>   > +    return dm_i2c_write(vc5->i2c, VC5_FEEDBACK_INT_DIV, fb, 5);
>>   > +}
>>   > +
>>   > +static const struct clk_ops vc5_pll_ops = {
>>   > +    .round_rate     = vc5_pll_round_rate,
>>   > +    .get_rate       = vc5_pll_recalc_rate,
>>   > +    .set_rate       = vc5_pll_set_rate,
>>   > +};
>>   > +
>>   > +static unsigned long vc5_fod_recalc_rate(struct clk *hw)
>>   > +{
>>   > +    struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
>>   > +    struct vc5_driver_data *vc = hwdata->vc5;
>>   > +    struct clk *parent = &vc->clk_pll.hw;
>>   > +    unsigned long parent_rate =  vc5_pll_recalc_rate(parent);
>>   > +
>>   > +    /* VCO frequency is divided by two before entering FOD */
>>   > +    u32 f_in = parent_rate / 2;
>>   > +    u32 div_int, div_frc;
>>   > +    u8 od_int[2];
>>   > +    u8 od_frc[4];
>>   > +
>>   > +    dm_i2c_read(vc->i2c, VC5_OUT_DIV_INT(hwdata->num, 0), od_int, 2);
>>   > +    dm_i2c_read(vc->i2c, VC5_OUT_DIV_FRAC(hwdata->num, 0), od_frc, 4);
>>   > +
>>   > +    div_int = (od_int[0] << 4) | (od_int[1] >> 4);
>>   > +    div_frc = (od_frc[0] << 22) | (od_frc[1] << 14) |
>>   > +              (od_frc[2] << 6) | (od_frc[3] >> 2);
>>   > +
>>   > +    /* Avoid division by zero if the output is not configured. */
>>   > +    if (div_int == 0 && div_frc == 0)
>>   > +            return 0;
>>   > +
>>   > +    /* The PLL divider has 12 integer bits and 30 fractional bits */
>>   > +    return div64_u64((u64)f_in << 24ULL, ((u64)div_int << 24ULL) + div_frc);
>>   > +}
>>   > +
>>   > +static unsigned long vc5_fod_round_rate(struct clk *hw, unsigned long rate)
>>   > +{
>>   > +    struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
>>   > +    struct vc5_driver_data *vc = hwdata->vc5;
>>   > +    struct clk *parent = &vc->clk_pll.hw;
>>   > +    unsigned long parent_rate =  vc5_pll_recalc_rate(parent);
>>   > +
>>   > +    /* VCO frequency is divided by two before entering FOD */
>>   > +    u32 f_in = parent_rate / 2;
>>   > +    u32 div_int;
>>   > +    u64 div_frc;
>>   > +
>>   > +    /* Determine integer part, which is 12 bit wide */
>>   > +    div_int = f_in / rate;
>>   > +
>>   > +    /*
>>   > +     * WARNING: The clock chip does not output signal if the integer part
>>   > +     *          of the divider is 0xfff and fractional part is non-zero.
>>   > +     *          Clamp the divider at 0xffe to keep the code simple.
>>   > +     */
>>   > +    if (div_int > 0xffe) {
>>   > +            div_int = 0xffe;
>>   > +            rate = f_in / div_int;
>>   > +    }
>>   > +
>>   > +    /* Determine best fractional part, which is 30 bit wide */
>>   > +    div_frc = f_in % rate;
>>   > +    div_frc <<= 24;
>>   > +    do_div(div_frc, rate);
>>   > +
>>   > +    hwdata->div_int = div_int;
>>   > +    hwdata->div_frc = (u32)div_frc;
>>   > +
>>   > +    return div64_u64((u64)f_in << 24ULL, ((u64)div_int << 24ULL) + div_frc);
>>   > +}
>>   > +
>>   > +static unsigned long vc5_fod_set_rate(struct clk *hw, unsigned long rate)
>>   > +{
>>   > +    struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
>>   > +    struct vc5_driver_data *vc5 = hwdata->vc5;
>>   > +
>>   > +    u8 data[14] = {
>>   > +            hwdata->div_frc >> 22, hwdata->div_frc >> 14,
>>   > +            hwdata->div_frc >> 6, hwdata->div_frc << 2,
>>   > +            0, 0, 0, 0, 0,
>>   > +            0, 0,
>>   > +            hwdata->div_int >> 4, hwdata->div_int << 4,
>>   > +            0
>>   > +    };
>>   > +
>>   > +    dm_i2c_write(vc5->i2c, VC5_OUT_DIV_FRAC(hwdata->num, 0), data, 14);
>>   > +
>>   > +    /*
>>   > +     * Toggle magic bit in undocumented register for unknown reason.
>>   > +     * This is what the IDT timing commander tool does and the chip
>>   > +     * datasheet somewhat implies this is needed, but the register
>>   > +     * and the bit is not documented.
>>   > +     */
>>   > +    vc5_update_bits(vc5->i2c, VC5_GLOBAL_REGISTER,
>>   > +                    VC5_GLOBAL_REGISTER_GLOBAL_RESET, 0);
>>   > +    vc5_update_bits(vc5->i2c, VC5_GLOBAL_REGISTER,
>>   > +                    VC5_GLOBAL_REGISTER_GLOBAL_RESET,
>>   > +                    VC5_GLOBAL_REGISTER_GLOBAL_RESET);
>>   > +
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static const struct clk_ops vc5_fod_ops = {
>>   > +    .round_rate     = vc5_fod_round_rate,
>>   > +    .get_rate       = vc5_fod_recalc_rate,
>>   > +    .set_rate       = vc5_fod_set_rate,
>>   > +};
>>   > +
>>   > +static int vc5_clk_out_prepare(struct clk *hw)
>>   > +{
>>   > +    struct udevice *dev;
>>   > +    struct vc5_driver_data *vc5;
>>   > +    struct vc5_out_data *hwdata;
>>   > +
>>   > +    const u8 mask = VC5_OUT_DIV_CONTROL_SELB_NORM |
>>   > +                    VC5_OUT_DIV_CONTROL_SEL_EXT |
>>   > +                    VC5_OUT_DIV_CONTROL_EN_FOD;
>>   > +    unsigned int src;
>>   > +    int ret;
>>   > +
>>   > +    uclass_get_device_by_name(UCLASS_CLK, clk_hw_get_name(hw), &dev);
>>   > +    vc5 = dev_get_priv(dev);
>>   > +    hwdata = &vc5->clk_out[hw->id];
>>   > +
>>   > +    /*
>>   > +     * If the input mux is disabled, enable it first and
>>   > +     * select source from matching FOD.
>>   > +     */
>>   > +
>>   > +    dm_i2c_read(vc5->i2c, VC5_OUT_DIV_CONTROL(hwdata->num), (uchar *)&src, 1);
>>   > +
>>   > +    if ((src & mask) == 0) {
>>   > +            src = VC5_OUT_DIV_CONTROL_RESET | VC5_OUT_DIV_CONTROL_EN_FOD;
>>   > +            ret = vc5_update_bits(vc5->i2c,
>>   > +                                  VC5_OUT_DIV_CONTROL(hwdata->num),
>>   > +                                  mask | VC5_OUT_DIV_CONTROL_RESET, src);
>>   > +            if (ret)
>>   > +                    return ret;
>>   > +    }
>>   > +
>>   > +    /* Enable the clock buffer */
>>   > +    vc5_update_bits(vc5->i2c, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
>>   > +                    VC5_CLK_OUTPUT_CFG1_EN_CLKBUF,
>>   > +                    VC5_CLK_OUTPUT_CFG1_EN_CLKBUF);
>>   > +    if (hwdata->clk_output_cfg0_mask) {
>>   > +            vc5_update_bits(vc5->i2c, VC5_CLK_OUTPUT_CFG(hwdata->num, 0),
>>   > +                            hwdata->clk_output_cfg0_mask,
>>   > +                            hwdata->clk_output_cfg0);
>>   > +    }
>>   > +
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static int vc5_clk_out_unprepare(struct clk *hw)
>>   > +{
>>   > +    struct udevice *dev;
>>   > +    struct vc5_driver_data *vc5;
>>   > +    struct vc5_out_data *hwdata;
>>   > +    int ret;
>>   > +
>>   > +    uclass_get_device_by_name(UCLASS_CLK, clk_hw_get_name(hw), &dev);
>>   > +    vc5 = dev_get_priv(dev);
>>   > +    hwdata = &vc5->clk_out[hw->id];
>>   > +
>>   > +    /* Disable the clock buffer */
>>   > +    ret = vc5_update_bits(vc5->i2c, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
>>   > +                          VC5_CLK_OUTPUT_CFG1_EN_CLKBUF, 0);
>>   > +
>>   > +    return ret;
>>   > +}
>>   > +
>>   > +static int vc5_clk_out_set_parent(struct vc5_driver_data *vc, u8 num, u8 index)
>>   > +{
>>   > +    const u8 mask = VC5_OUT_DIV_CONTROL_RESET |
>>   > +                    VC5_OUT_DIV_CONTROL_SELB_NORM |
>>   > +                    VC5_OUT_DIV_CONTROL_SEL_EXT |
>>   > +                    VC5_OUT_DIV_CONTROL_EN_FOD;
>>   > +    const u8 extclk = VC5_OUT_DIV_CONTROL_SELB_NORM |
>>   > +                      VC5_OUT_DIV_CONTROL_SEL_EXT;
>>   > +    u8 src = VC5_OUT_DIV_CONTROL_RESET;
>>   > +
>>   > +    if (index == 0)
>>   > +            src |= VC5_OUT_DIV_CONTROL_EN_FOD;
>>   > +    else
>>   > +            src |= extclk;
>>   > +
>>   > +    return vc5_update_bits(vc->i2c, VC5_OUT_DIV_CONTROL(num), mask, src);
>>   > +}
>>   > +
>>   > +/*
>>   > + * The device references to the Versaclock point to the head, so xlate needs to
>>   > + * redirect it to clk_out[idx]
>>   > + */
>>   > +static int vc5_clk_out_xlate(struct clk *hw, struct ofnode_phandle_args *args)
>>   > +{
>>   > +    unsigned int idx = args->args[0];
>>   > +
>>   > +    if (args->args_count != 1) {
>>   > +            debug("Invaild args_count: %d\n", args->args_count);
>>   > +            return -EINVAL;
>>   > +    }
>>   > +
>>   > +    hw->id = idx;
>>   > +
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static unsigned long vc5_clk_out_set_rate(struct clk *hw, unsigned long rate)
>>   > +{
>>   > +    struct udevice *dev;
>>   > +    struct vc5_driver_data *vc;
>>   > +    struct clk *parent;
>>   > +
>>   > +    uclass_get_device_by_name(UCLASS_CLK, clk_hw_get_name(hw), &dev);
>>   > +    vc = dev_get_priv(dev);
>>   > +    parent = clk_get_parent(&vc->clk_out[hw->id].hw);
>>   > +
>>   > +    /* setting the output rate really means setting the parent FOD rate */
>>   > +    return clk_set_rate(parent, clk_round_rate(parent, rate));
>>   > +}
>>   > +
>>   > +static unsigned long vc5_clk_out_get_rate(struct clk *hw)
>>   > +{
>>   > +    return clk_get_parent_rate(hw);
>>   > +}
>>   > +
>>   > +static const struct clk_ops vc5_clk_out_ops = {
>>   > +    .enable = vc5_clk_out_prepare,
>>   > +    .disable        = vc5_clk_out_unprepare,
>>   > +    .set_rate       = vc5_clk_out_set_rate,
>>   > +    .get_rate       = vc5_clk_out_get_rate,
>>   > +};
>>   > +
>>   > +static const struct clk_ops vc5_clk_out_sel_ops = {
>>   > +    .enable = vc5_clk_out_prepare,
>>   > +    .disable        = vc5_clk_out_unprepare,
>>   > +    .get_rate       = vc5_clk_out_get_rate,
>>   > +};
>>   > +
>>   > +static const struct clk_ops vc5_clk_ops = {
>>   > +    .enable = vc5_clk_out_prepare,
>>   > +    .disable        = vc5_clk_out_unprepare,
>>   > +    .of_xlate       = vc5_clk_out_xlate,
>>   > +    .set_rate       = vc5_clk_out_set_rate,
>>   > +    .get_rate       = vc5_clk_out_get_rate,
>>   > +};
>>   > +
>>   > +static int vc5_map_index_to_output(const enum vc5_model model,
>>   > +                               const unsigned int n)
>>   > +{
>>   > +    switch (model) {
>>   > +    case IDT_VC5_5P49V5933:
>>   > +            return (n == 0) ? 0 : 3;
>>   > +    case IDT_VC5_5P49V5923:
>>   > +    case IDT_VC5_5P49V5925:
>>   > +    case IDT_VC5_5P49V5935:
>>   > +    case IDT_VC6_5P49V6901:
>>   > +    case IDT_VC6_5P49V6965:
>>   > +    default:
>>   > +            return n;
>>   > +    }
>>   > +}
>>   > +
>>   > +static int vc5_update_mode(ofnode np_output,
>>   > +                       struct vc5_out_data *clk_out)
>>   > +{
>>   > +    u32 value;
>>   > +
>>   > +    if (!ofnode_read_u32(np_output, "idt,mode", &value)) {
>>   > +            clk_out->clk_output_cfg0_mask |= VC5_CLK_OUTPUT_CFG0_CFG_MASK;
>>   > +            switch (value) {
>>   > +            case VC5_CLK_OUTPUT_CFG0_CFG_LVPECL:
>>   > +            case VC5_CLK_OUTPUT_CFG0_CFG_CMOS:
>>   > +            case VC5_CLK_OUTPUT_CFG0_CFG_HCSL33:
>>   > +            case VC5_CLK_OUTPUT_CFG0_CFG_LVDS:
>>   > +            case VC5_CLK_OUTPUT_CFG0_CFG_CMOS2:
>>   > +            case VC5_CLK_OUTPUT_CFG0_CFG_CMOSD:
>>   > +            case VC5_CLK_OUTPUT_CFG0_CFG_HCSL25:
>>   > +                    clk_out->clk_output_cfg0 |=
>>   > +                        value << VC5_CLK_OUTPUT_CFG0_CFG_SHIFT;
>>   > +                    break;
>>   > +            default:
>>   > +                    return -EINVAL;
>>   > +            }
>>   > +    }
>>   > +
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static int vc5_update_power(ofnode np_output, struct vc5_out_data *clk_out)
>>   > +{
>>   > +    u32 value;
>>   > +
>>   > +    if (!ofnode_read_u32(np_output, "idt,voltage-microvolt", &value)) {
>>   > +            clk_out->clk_output_cfg0_mask |= VC5_CLK_OUTPUT_CFG0_PWR_MASK;
>>   > +            switch (value) {
>>   > +            case 1800000:
>>   > +                    clk_out->clk_output_cfg0 |= VC5_CLK_OUTPUT_CFG0_PWR_18;
>>   > +                    break;
>>   > +            case 2500000:
>>   > +                    clk_out->clk_output_cfg0 |= VC5_CLK_OUTPUT_CFG0_PWR_25;
>>   > +                    break;
>>   > +            case 3300000:
>>   > +                    clk_out->clk_output_cfg0 |= VC5_CLK_OUTPUT_CFG0_PWR_33;
>>   > +                    break;
>>   > +            default:
>>   > +                    return -EINVAL;
>>   > +            }
>>   > +    }
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static int vc5_map_cap_value(u32 femtofarads)
>>   > +{
>>   > +    int mapped_value;
>>   > +
>>   > +    /*
>>   > +     * The datasheet explicitly states 9000 - 25000 with 0.5pF
>>   > +     * steps, but the Programmer's guide shows the steps are 0.430pF.
>>   > +     * After getting feedback from Renesas, the .5pF steps were the
>>   > +     * goal, but 430nF was the actual values.
>>   > +     * Because of this, the actual range goes to 22760 instead of 25000
>>   > +     */
>>   > +    if (femtofarads < 9000 || femtofarads > 22760)
>>   > +            return -EINVAL;
>>   > +
>>   > +    /*
>>   > +     * The Programmer's guide shows XTAL[5:0] but in reality,
>>   > +     * XTAL[0] and XTAL[1] are both LSB which makes the math
>>   > +     * strange.  With clarfication from Renesas, setting the
>>   > +     * values should be simpler by ignoring XTAL[0]
>>   > +     */
>>   > +    mapped_value = DIV_ROUND_CLOSEST(femtofarads - 9000, 430);
>>   > +
>>   > +    /*
>>   > +     * Since the calculation ignores XTAL[0], there is one
>>   > +     * special case where mapped_value = 32.  In reality, this means
>>   > +     * the real mapped value should be 111111b.  In other cases,
>>   > +     * the mapped_value needs to be shifted 1 to the left.
>>   > +     */
>>   > +    if (mapped_value > 31)
>>   > +            mapped_value = 0x3f;
>>   > +    else
>>   > +            mapped_value <<= 1;
>>   > +
>>   > +    return mapped_value;
>>   > +}
>>   > +
>>   > +static int vc5_update_cap_load(ofnode node, struct vc5_driver_data *vc5)
>>   > +{
>>   > +    u32 value;
>>   > +    int mapped_value;
>>   > +
>>   > +    if (!ofnode_read_u32(node, "idt,xtal-load-femtofarads", &value)) {
>>   > +            mapped_value = vc5_map_cap_value(value);
>>   > +
>>   > +            if (mapped_value < 0)
>>   > +                    return mapped_value;
>>   > +
>>   > +            /*
>>   > +             * The mapped_value is really the high 6 bits of
>>   > +             * VC5_XTAL_X1_LOAD_CAP and VC5_XTAL_X2_LOAD_CAP, so
>>   > +             * shift the value 2 places.
>>   > +             */
>>   > +            vc5_update_bits(vc5->i2c, VC5_XTAL_X1_LOAD_CAP, ~0x03, mapped_value << 2);
>>   > +            vc5_update_bits(vc5->i2c, VC5_XTAL_X2_LOAD_CAP, ~0x03, mapped_value << 2);
>>   > +    }
>>   > +
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static int vc5_update_slew(ofnode np_output, struct vc5_out_data *clk_out)
>>   > +{
>>   > +    u32 value;
>>   > +
>>   > +    if (!ofnode_read_u32(np_output, "idt,slew-percent", &value)) {
>>   > +            clk_out->clk_output_cfg0_mask |= VC5_CLK_OUTPUT_CFG0_SLEW_MASK;
>>   > +
>>   > +            switch (value) {
>>   > +            case 80:
>>   > +                    clk_out->clk_output_cfg0 |= VC5_CLK_OUTPUT_CFG0_SLEW_80;
>>   > +                    break;
>>   > +            case 85:
>>   > +                    clk_out->clk_output_cfg0 |= VC5_CLK_OUTPUT_CFG0_SLEW_85;
>>   > +                    break;
>>   > +            case 90:
>>   > +                    clk_out->clk_output_cfg0 |= VC5_CLK_OUTPUT_CFG0_SLEW_90;
>>   > +                    break;
>>   > +            case 100:
>>   > +                    clk_out->clk_output_cfg0 |=
>>   > +                        VC5_CLK_OUTPUT_CFG0_SLEW_100;
>>   > +                    break;
>>   > +            default:
>>   > +                    return -EINVAL;
>>   > +            }
>>   > +    }
>>   > +    return 0;
>>   > +}
>>   > +
>>   > +static int vc5_get_output_config(struct udevice *dev,
>>   > +                             struct vc5_out_data *clk_out)
>>   > +{
>>   > +    ofnode np_output;
>>   > +    char child_name[5];
>>   > +    int ret = 0;
>>   > +
>>   > +    sprintf(child_name, "OUT%d", clk_out->num + 1);
>>   > +
>>   > +    np_output = dev_read_subnode(dev, child_name);
>>   > +
>>   > +    if (!ofnode_valid(np_output)) {
>>
>> Same comment as last time: use dev_read_u32() and friends instead of
>> passing around an ofnode.
> 
> Sean,
> 
> I am not sure I understand what you're asking here. I will admit I am
> fairly new to the U-Boot clock API.
> 
> We have multiple child nodes called OUTx where x can vary from chip to
> chip and the contents inside these OUTx nodes may also vary depending
> on the application.
> 
> versaclock: clock-controller at 6a {
>      ...
>       OUT1 {
>            idt,mode = <VC5_CMOS>;
>            idt,voltage-microvolt = <1800000>;
>            idt,slew-percent = <100>;
>       };
>      ...
>      OUTx {
>            idt,mode = <VC5_CMOS>;
>            idt,voltage-microvolt = <1800000>;
>            idt,slew-percent = <100>;
>       };
> 
> };
> 
> Since the *dev in this case points to the parent, clock-controller at 6a,
>   we need to traverse into the corresponding OUTx node based on the
> clock index, clk_out_num + 1.
> Each OUTx node is independent of the others so searching for idt,mode,
> idt,voltage-microvolt, and idt,slew-precent from the device tree may
> yield different values depending on which OUTx node is being read.
> They may not be the same.
> 
> The idea behind this is to identify the OUTx node, and then read the
> values accordingly to that node.  Using dev_read32, I can see that we
> can read the properties, but it's not clear to me how to specify which
> child subnode we'd be reading.
> If we eliminate the passing of the subnode, then each function called
> would have to determine the subnode and that seems like it would be
> duplicating code.

Ah, ok. It seems like I misunderstood. Thisn is fine then.

--Sean

>>
>>   > +            dev_dbg(dev, "!ofnode_valid(np_output)\n");
>>   > +            return 0;
>>   > +    }
>>   > +
>>   > +    ret = vc5_update_mode(np_output, clk_out);
>>   > +    if (ret)
>>   > +            goto output_error;
>>   > +
>>   > +    ret = vc5_update_power(np_output, clk_out);
>>   > +    if (ret)
>>   > +            goto output_error;
>>   > +
>>   > +    ret = vc5_update_slew(np_output, clk_out);
>>   > +
>>   > +output_error:
>>   > +    if (ret)
>>   > +            dev_dbg(dev, "Invalid clock output configuration OUT%d\n", clk_out->num + 1);
>>   > +
>>   > +    return ret;
>>   > +}
>>   > +
>>   > +static char *versaclock_get_name(const char *dev_name, const char *clk_name, int index)
>>   > +{
>>   > +    int length;
>>   > +    char *buf;
>>   > +
>>   > +    if (index < 0)
>>   > +            length = snprintf(NULL, 0, "%s.%s", dev_name, clk_name) + 1;
>>   > +    else
>>   > +            length = snprintf(NULL, 0, "%s.%s%d", dev_name, clk_name, index) + 1;
>>   > +
>>   > +    buf = malloc(length);
>>   > +    if (!buf)
>>   > +            ERR_PTR(-ENOMEM);
>>   > +
>>   > +    if (index < 0)
>>   > +            snprintf(buf, length, "%s.%s", dev_name, clk_name);
>>   > +    else
>>   > +            snprintf(buf, length, "%s.%s%d", dev_name, clk_name, index);
>>   > +
>>   > +    return buf;
>>   > +}
>>   > +
>>   > +int versaclock_probe(struct udevice *dev)
>>   > +{
>>   > +    struct vc5_driver_data *vc5 = dev_get_priv(dev);
>>   > +    struct vc5_chip_info *chip = (void *)dev_get_driver_data(dev);
>>   > +    unsigned int n, idx = 0;
>>   > +    char *mux_name, *pfd_name, *pll_name, *outsel_name;
>>   > +    char *out_name[VC5_MAX_CLK_OUT_NUM];
>>   > +    char *fod_name[VC5_MAX_FOD_NUM];
>>   > +    int ret;
>>   > +    u64 val;
>>   > +
>>   > +    val = (u64)dev_read_addr_ptr(dev);
>>   > +    ret = i2c_get_chip(dev->parent, val, 1, &vc5->i2c);
>>   > +
>>   > +    if (ret) {
>>   > +            dev_err(dev, "I2C probe failed.\n");
>>   > +            return ret;
>>   > +    }
>>   > +
>>   > +    vc5->chip_info = chip;
>>   > +    vc5->pin_xin = devm_clk_get(dev, "xin");
>>   > +
>>   > +    if (IS_ERR(vc5->pin_xin))
>>   > +            dev_err(dev, "failed to get xin clock\n");
>>
>> And the dev_dbg/log_msg_ret comments apply to this probe function as
>> well.
> 
> I'll replace the dev_err with dev_dgb.
> 
>>
>>   > +
>>   > +    ret = clk_enable(vc5->pin_xin);
>>   > +    if (ret)
>>   > +            dev_err(dev, "failed to enable XIN clock\n");
>>   > +
>>   > +    vc5->pin_clkin = devm_clk_get(dev, "clkin");
>>   > +
>>   > +    /* Register clock input mux */
>>   > +    if (!IS_ERR(vc5->pin_xin)) {
>>   > +            vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
>>   > +    } else if (vc5->chip_info->flags & VC5_HAS_INTERNAL_XTAL) {
>>   > +            if (IS_ERR(vc5->pin_xin))
>>   > +                    return PTR_ERR(vc5->pin_xin);
>>   > +            vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
>>   > +    }
>>   > +
>>   > +    mux_name = versaclock_get_name(dev->name, "mux", -1);
>>   > +    if (IS_ERR(mux_name))
>>   > +            printf("mux_name: %lu\n", PTR_ERR(mux_name));
>>   > +
>>   > +    clk_register(&vc5->clk_mux, "versaclock-mux", mux_name, vc5->pin_xin->dev->name);
>>   > +
>>   > +    if (!IS_ERR(vc5->pin_xin))
>>   > +            vc5_mux_set_parent(&vc5->clk_mux, 1);
>>   > +    else
>>   > +            vc5_mux_set_parent(&vc5->clk_mux, 0);
>>   > +
>>   > +    /* Configure Optional Loading Capacitance for external XTAL */
>>   > +    if (!(vc5->chip_info->flags & VC5_HAS_INTERNAL_XTAL)) {
>>   > +            ret = vc5_update_cap_load(dev_ofnode(dev), vc5);
>>   > +            if (ret)
>>   > +                    dev_err(dev, "failed to vc5_update_cap_load\n");
>>   > +    }
>>   > +
>>   > +    /* Register PFD */
>>   > +    pfd_name = versaclock_get_name(dev->name, "pfd", -1);
>>   > +    if (IS_ERR(pfd_name))
>>   > +            printf("pfd_name: %lu\n", PTR_ERR(pfd_name));
>>
>> In particular, printf is almost always incorrect when used in a driver.
> 
> Sorry, I have egg on my face.  I added some new printfs for debugging
> my new error handling, and I forgot to remove them.
> 
> I will make sure the printfs are gone.  Sorry about that.
> 
>>
>> --Sean
>>
>>   > +
>>   > +    ret = clk_register(&vc5->clk_pfd, "versaclock-pfd", pfd_name, vc5->clk_mux.dev->name);
>>   > +    if (ret)
>>   > +            goto free_mux;
>>   > +
>>   > +    /* Register PLL */
>>   > +    vc5->clk_pll.num = 0;
>>   > +    vc5->clk_pll.vc5 = vc5;
>>   > +    pll_name = versaclock_get_name(dev->name, "pll", -1);
>>   > +    if (IS_ERR(pll_name)) {
>>   > +            ret = PTR_ERR(pll_name);
>>   > +            goto free_pfd;
>>   > +    }
>>   > +
>>   > +    ret = clk_register(&vc5->clk_pll.hw, "versaclock-pll", pll_name, vc5->clk_pfd.dev->name);
>>   > +    if (ret)
>>   > +            goto free_pll;
>>   > +
>>   > +    /* Register FODs */
>>   > +    for (n = 0; n < vc5->chip_info->clk_fod_cnt; n++) {
>>   > +            fod_name[n] = versaclock_get_name(dev->name, "fod", n);
>>   > +            if (IS_ERR(pll_name))
>>   > +                    printf("fod_name[%d]: %lu\n", n, PTR_ERR(fod_name[n]));
>>   > +            idx = vc5_map_index_to_output(vc5->chip_info->model, n);
>>   > +            vc5->clk_fod[n].num = idx;
>>   > +            vc5->clk_fod[n].vc5 = vc5;
>>   > +            ret = clk_register(&vc5->clk_fod[n].hw, "versaclock-fod", fod_name[n],
>>   > +                               vc5->clk_pll.hw.dev->name);
>>   > +            if (ret)
>>   > +                    goto free_fod;
>>   > +    }
>>   > +
>>   > +    /* Register MUX-connected OUT0_I2C_SELB output */
>>   > +    vc5->clk_out[0].num = idx;
>>   > +    vc5->clk_out[0].vc5 = vc5;
>>   > +    outsel_name = versaclock_get_name(dev->name, "out0_sel_i2cb", -1);
>>   > +    if (IS_ERR(outsel_name)) {
>>   > +            ret = PTR_ERR(outsel_name);
>>   > +            goto free_fod;
>>   > +    };
>>   > +
>>   > +    ret = clk_register(&vc5->clk_out[0].hw, "versaclock-outsel",  outsel_name,
>>   > +                       vc5->clk_mux.dev->name);
>>   > +    if (ret)
>>   > +            goto free_selb;
>>   > +
>>   > +    /* Register FOD-connected OUTx outputs */
>>   > +    for (n = 1; n < vc5->chip_info->clk_out_cnt; n++) {
>>   > +            idx = vc5_map_index_to_output(vc5->chip_info->model, n - 1);
>>   > +            out_name[n] = versaclock_get_name(dev->name, "out", n);
>>   > +            if (IS_ERR(out_name[n])) {
>>   > +                    ret = PTR_ERR(out_name[n]);
>>   > +                    goto free_selb;
>>   > +            }
>>   > +            vc5->clk_out[n].num = idx;
>>   > +            vc5->clk_out[n].vc5 = vc5;
>>   > +            ret = clk_register(&vc5->clk_out[n].hw, "versaclock-out", out_name[n],
>>   > +                               vc5->clk_fod[idx].hw.dev->name);
>>   > +            if (ret)
>>   > +                    goto free_out;
>>   > +            vc5_clk_out_set_parent(vc5, idx, 0);
>>   > +
>>   > +            /* Fetch Clock Output configuration from DT (if specified) */
>>   > +            ret = vc5_get_output_config(dev, &vc5->clk_out[n]);
>>   > +            if (ret) {
>>   > +                    dev_err(dev, "failed to vc5_get_output_config()\n");
>>   > +                    goto free_out;
>>   > +            }
>>   > +    }
>>   > +
>>   > +    return 0;
>>   > +
>>   > +free_out:
>>   > +    for (n = 1; n < vc5->chip_info->clk_out_cnt; n++) {
>>   > +            clk_free(&vc5->clk_out[n].hw);
>>   > +            free(out_name[n]);
>>   > +    }
>>   > +free_selb:
>>   > +    clk_free(&vc5->clk_out[0].hw);
>>   > +    free(outsel_name);
>>   > +free_fod:
>>   > +    for (n = 0; n < vc5->chip_info->clk_fod_cnt; n++) {
>>   > +            clk_free(&vc5->clk_fod[n].hw);
>>   > +            free(fod_name[n]);
>>   > +    }
>>   > +free_pll:
>>   > +    clk_free(&vc5->clk_pll.hw);
>>   > +    free(pll_name);
>>   > +free_pfd:
>>   > +    clk_free(&vc5->clk_pfd);
>>   > +    free(pfd_name);
>>   > +free_mux:
>>   > +    clk_free(&vc5->clk_mux);
>>   > +    free(mux_name);
>>   > +
>>   > +    return ret;
>>   > +}
>>   > +
>>   > +static const struct udevice_id versaclock_ids[] = {
>>   > +    { .compatible = "idt,5p49v5923", .data = (ulong)&idt_5p49v5923_info },
>>   > +    { .compatible = "idt,5p49v5925", .data = (ulong)&idt_5p49v5925_info },
>>   > +    { .compatible = "idt,5p49v5933", .data = (ulong)&idt_5p49v5933_info },
>>   > +    { .compatible = "idt,5p49v5935", .data = (ulong)&idt_5p49v5935_info },
>>   > +    { .compatible = "idt,5p49v6901", .data = (ulong)&idt_5p49v6901_info },
>>   > +    { .compatible = "idt,5p49v6965", .data = (ulong)&idt_5p49v6965_info },
>>   > +    {},
>>   > +};
>>   > +
>>   > +U_BOOT_DRIVER(versaclock) = {
>>   > +    .name           = "versaclock",
>>   > +    .id             = UCLASS_CLK,
>>   > +    .ops            = &vc5_clk_ops,
>>   > +    .of_match       = versaclock_ids,
>>   > +    .probe          = versaclock_probe,
>>   > +    .priv_auto      = sizeof(struct vc5_driver_data),
>>   > +};
>>   > +
>>   > +U_BOOT_DRIVER(versaclock_mux) = {
>>   > +    .name           = "versaclock-mux",
>>   > +    .id             = UCLASS_CLK,
>>   > +    .ops            = &vc5_mux_ops,
>>   > +};
>>   > +
>>   > +U_BOOT_DRIVER(versaclock_pfd) = {
>>   > +    .name           = "versaclock-pfd",
>>   > +    .id             = UCLASS_CLK,
>>   > +    .ops            = &vc5_pfd_ops,
>>   > +};
>>   > +
>>   > +U_BOOT_DRIVER(versaclock_pll) = {
>>   > +    .name           = "versaclock-pll",
>>   > +    .id             = UCLASS_CLK,
>>   > +    .ops            = &vc5_pll_ops,
>>   > +};
>>   > +
>>   > +U_BOOT_DRIVER(versaclock_fod) = {
>>   > +    .name           = "versaclock-fod",
>>   > +    .id             = UCLASS_CLK,
>>   > +    .ops            = &vc5_fod_ops,
>>   > +};
>>   > +
>>   > +U_BOOT_DRIVER(versaclock_out) = {
>>   > +    .name           = "versaclock-out",
>>   > +    .id             = UCLASS_CLK,
>>   > +    .ops            = &vc5_clk_out_ops,
>>   > +};
>>   > +
>>   > +U_BOOT_DRIVER(versaclock_outsel) = {
>>   > +    .name           = "versaclock-outsel",
>>   > +    .id             = UCLASS_CLK,
>>   > +    .ops            = &vc5_clk_out_sel_ops,
>>   > +};
>>   >


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