On 01/10/2017 07:50 PM, Marek Vasut wrote:
> Add driver for IDT VersaClock 5 5P49V5923 and 5P49V5933 chips. These
> chips have two clock inputs, XTAL or CLK, which are muxed into single
> PLL/VCO input. In case of 5P49V5923, the XTAL in built into the chip
> while the 5P49V5923 requires external XTAL.
> 
> The PLL feeds two fractional dividers. Each fractional divider feeds
> output mux, which allows selecting between clock from the fractional
> divider itself or from output mux on output N-1. In case of output
> mux 0, the output N-1 is instead connected to the output from the mux
> feeding the PLL.
> 
> The driver thus far supports only the 5P49V5923 and 5P49V5933, while
> it should be easily extensible to the whole 5P49V59xx family of chips
> as they are all pretty similar.
> 
> Signed-off-by: Marek Vasut <marek.va...@gmail.com>
> Cc: Michael Turquette <mturque...@baylibre.com>
> Cc: Stephen Boyd <sb...@codeaurora.org>

+Cc Laurent, linux-renesas

> ---
> V2: - Drop address-cells and size-cells from the binding
>     - Add clock-names to the binding
>     - Drop vc5_input_names
>     - Fix assortment of spelling mistakes
>     - Switch div_frc and div_int datatype to uXX
>     - Switch f_in to u32
>     - Add missing remove
>     - Define macros for handling XIN and CLKIN
>     - Rework the FOD fractional divider calculation, this was wrong
>       and made the output clock be off considerably under certain
>       circumstances (when the fractional part was large).
> V3: - Rework the MUX frequency recalculation and divider configration
>       so that it fits into the clock framework
>     - Add support for 5P49V5933 chip to lay groundwork for adding more
>       chips easily.
>     - Export the OUT0_SEL_I2CB output into the clock framework, so it
>       can be accessed from DT as well. WARNING: This does change the
>       bindings, clock0 is now the OUT0_SEL_I2CB, clock1 is OUT1 and
>       clock2 is OUT2 (or OUT4 on the 5P49V5933).
>     - Drop unnecessary caching of pin_*_name clock name and clk_hw structures
>       in driver data.
>     - Add missing MAINTAINERS entry
> V4: - Support also 5P49V5923A by dropping the B from the bindings and
>       code. According to the update notice, the chips are identical
>       except for disabling the VCO monitoring, which is internal
>       factory-defined bit and has no impact on silicon performance.
> ---
>  .../devicetree/bindings/clock/idt,versaclock5.txt  |  43 ++
>  MAINTAINERS                                        |   5 +
>  drivers/clk/Kconfig                                |  10 +
>  drivers/clk/Makefile                               |   1 +
>  drivers/clk/clk-versaclock5.c                      | 821 
> +++++++++++++++++++++
>  5 files changed, 880 insertions(+)
>  create mode 100644 
> Documentation/devicetree/bindings/clock/idt,versaclock5.txt
>  create mode 100644 drivers/clk/clk-versaclock5.c
> 
> diff --git a/Documentation/devicetree/bindings/clock/idt,versaclock5.txt 
> b/Documentation/devicetree/bindings/clock/idt,versaclock5.txt
> new file mode 100644
> index 000000000000..82ebed9a8a15
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/idt,versaclock5.txt
> @@ -0,0 +1,43 @@
> +Binding for IDT VersaClock5 programmable i2c clock generator.
> +
> +The IDT VersaClock5 are programmable i2c clock generators providing
> +from 3 to 12 output clocks.
> +
> +==I2C device node==
> +
> +Required properties:
> +- compatible:        shall be one of "idt,5p49v5923" , "idt,5p49v5933".
> +- reg:               i2c device address, shall be 0x68 or 0x6a.
> +- #clock-cells:      from common clock binding; shall be set to 1.
> +- clocks:    from common clock binding; list of parent clock handles,
> +             - 5p49v5923: (required) either or both of XTAL or CLKIN
> +                                     reference clock.
> +             - 5p49v5933: (optional) property not present (internal
> +                                     Xtal used) or CLKIN reference
> +                                     clock.
> +- clock-names:       from common clock binding; clock input names, can be
> +             - 5p49v5923: (required) either or both of "xin", "clkin".
> +             - 5p49v5933: (optional) property not present or "clkin".
> +
> +==Example==
> +
> +/* 25MHz reference crystal */
> +ref25: ref25m {
> +     compatible = "fixed-clock";
> +     #clock-cells = <0>;
> +     clock-frequency = <25000000>;
> +};
> +
> +i2c-master-node {
> +
> +     /* IDT 5P49V5923 i2c clock generator */
> +     vc5: clock-generator@6a {
> +             compatible = "idt,5p49v5923";
> +             reg = <0x6a>;
> +             #clock-cells = <1>;
> +
> +             /* Connect XIN input to 25MHz reference */
> +             clocks = <&ref25m>;
> +             clock-names = "xin";
> +     };
> +};
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 162d904d5cc3..890fc9e3c191 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6113,6 +6113,11 @@ S:     Maintained
>  F:   drivers/mfd/lpc_ich.c
>  F:   drivers/gpio/gpio-ich.c
>  
> +IDT VersaClock 5 CLOCK DRIVER
> +M:   Marek Vasut <marek.va...@gmail.com>
> +S:   Maintained
> +F:   drivers/clk/clk-versaclock5.c
> +
>  IDE SUBSYSTEM
>  M:   "David S. Miller" <da...@davemloft.net>
>  L:   linux-...@vger.kernel.org
> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
> index 6a8ac04bedeb..9160e6712067 100644
> --- a/drivers/clk/Kconfig
> +++ b/drivers/clk/Kconfig
> @@ -198,6 +198,16 @@ config COMMON_CLK_OXNAS
>       ---help---
>         Support for the OXNAS SoC Family clocks.
>  
> +config COMMON_CLK_VC5
> +     tristate "Clock driver for IDT VersaClock5 devices"
> +     depends on I2C
> +     depends on OF
> +     select REGMAP_I2C
> +     help
> +     ---help---
> +       This driver supports the IDT VersaClock5 programmable clock
> +       generator.
> +
>  source "drivers/clk/bcm/Kconfig"
>  source "drivers/clk/hisilicon/Kconfig"
>  source "drivers/clk/mediatek/Kconfig"
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 925081ec14c0..e0754d9fc2df 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -46,6 +46,7 @@ obj-$(CONFIG_ARCH_TANGO)            += clk-tango4.o
>  obj-$(CONFIG_CLK_TWL6040)            += clk-twl6040.o
>  obj-$(CONFIG_ARCH_U300)                      += clk-u300.o
>  obj-$(CONFIG_ARCH_VT8500)            += clk-vt8500.o
> +obj-$(CONFIG_COMMON_CLK_VC5)         += clk-versaclock5.o
>  obj-$(CONFIG_COMMON_CLK_WM831X)              += clk-wm831x.o
>  obj-$(CONFIG_COMMON_CLK_XGENE)               += clk-xgene.o
>  
> diff --git a/drivers/clk/clk-versaclock5.c b/drivers/clk/clk-versaclock5.c
> new file mode 100644
> index 000000000000..14f518e84d6d
> --- /dev/null
> +++ b/drivers/clk/clk-versaclock5.c
> @@ -0,0 +1,821 @@
> +/*
> + * Driver for IDT Versaclock 5
> + *
> + * Copyright (C) 2017 Marek Vasut <marek.va...@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +/*
> + * Possible optimizations:
> + * - Use spread spectrum
> + * - Use integer divider in FOD if applicable
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/clk-provider.h>
> +#include <linux/delay.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/rational.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.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_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_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)
> +
> +/* Supported IDT VC5 models. */
> +enum vc5_model {
> +     IDT_VC5_5P49V5923,
> +     IDT_VC5_5P49V5933,
> +};
> +
> +struct vc5_driver_data;
> +
> +struct vc5_hw_data {
> +     struct clk_hw           hw;
> +     struct vc5_driver_data  *vc5;
> +     u32                     div_int;
> +     u32                     div_frc;
> +     unsigned int            num;
> +};
> +
> +struct vc5_driver_data {
> +     struct i2c_client       *client;
> +     struct regmap           *regmap;
> +     enum vc5_model          model;
> +
> +     struct clk              *pin_xin;
> +     struct clk              *pin_clkin;
> +     unsigned char           clk_mux_ins;
> +     struct clk_hw           clk_mux;
> +     struct vc5_hw_data      clk_pll;
> +     struct vc5_hw_data      clk_fod[2];
> +     struct vc5_hw_data      clk_out[3];
> +};
> +
> +static const char * const vc5_mux_names[] = {
> +     "mux"
> +};
> +
> +static const char * const vc5_pll_names[] = {
> +     "pll"
> +};
> +
> +static const char * const vc5_fod_names[] = {
> +     "fod0", "fod1", "fod2", "fod3",
> +};
> +
> +static const char * const vc5_clk_out_names[] = {
> +     "out0_sel_i2cb", "out1", "out2", "out3", "out4",
> +};
> +
> +/*
> + * VersaClock5 i2c regmap
> + */
> +static bool vc5_regmap_is_writeable(struct device *dev, unsigned int reg)
> +{
> +     /* Factory reserved regs, make them read-only */
> +     if (reg >= 0 && reg <= 0xf)
> +             return false;
> +
> +     /* Factory reserved regs, make them read-only */
> +     if (reg == 0x14 || reg == 0x1c || reg == 0x1d)
> +             return false;
> +
> +     return true;
> +}
> +
> +static const struct regmap_config vc5_regmap_config = {
> +     .reg_bits = 8,
> +     .val_bits = 8,
> +     .cache_type = REGCACHE_RBTREE,
> +     .max_register = 0x76,
> +     .writeable_reg = vc5_regmap_is_writeable,
> +};
> +
> +/*
> + * VersaClock5 input multiplexer between XTAL and CLKIN divider
> + */
> +static unsigned char vc5_mux_get_parent(struct clk_hw *hw)
> +{
> +     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;
> +     unsigned int src;
> +
> +     regmap_read(vc5->regmap, VC5_PRIM_SRC_SHDN, &src);
> +     src &= mask;
> +
> +     if (src == VC5_PRIM_SRC_SHDN_EN_XTAL)
> +             return 0;
> +
> +     if (src == VC5_PRIM_SRC_SHDN_EN_CLKIN)
> +             return 1;
> +
> +     dev_warn(&vc5->client->dev,
> +              "Invalid clock input configuration (%02x)\n", src);
> +     return 0;
> +}
> +
> +static int vc5_mux_set_parent(struct clk_hw *hw, u8 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;
> +             if (vc5->clk_mux_ins == VC5_MUX_IN_CLKIN)
> +                     src = VC5_PRIM_SRC_SHDN_EN_CLKIN;
> +     }
> +
> +     return regmap_update_bits(vc5->regmap, VC5_PRIM_SRC_SHDN, mask, src);
> +}
> +
> +static unsigned long vc5_mux_recalc_rate(struct clk_hw *hw,
> +                                      unsigned long parent_rate)
> +{
> +     struct vc5_driver_data *vc5 =
> +             container_of(hw, struct vc5_driver_data, clk_mux);
> +     unsigned int prediv, div;
> +
> +     regmap_read(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV, &prediv);
> +
> +     /* The bypass_prediv is set, PLL fed from Ref_in directly. */
> +     if (prediv & VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV)
> +             return parent_rate;
> +
> +     regmap_read(vc5->regmap, VC5_REF_DIVIDER, &div);
> +
> +     /* 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 long vc5_mux_round_rate(struct clk_hw *hw, unsigned long rate,
> +                            unsigned long *parent_rate)
> +{
> +     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 int vc5_mux_set_rate(struct clk_hw *hw, unsigned long rate,
> +                         unsigned long parent_rate)
> +{
> +     struct vc5_driver_data *vc5 =
> +             container_of(hw, struct vc5_driver_data, clk_mux);
> +     unsigned long idiv;
> +     u8 div;
> +
> +     /* CLKIN within range of PLL input, feed directly to PLL. */
> +     if (parent_rate <= 50000000) {
> +             regmap_update_bits(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV,
> +                                VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV,
> +                                VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV);
> +             regmap_update_bits(vc5->regmap, 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);
> +
> +     regmap_update_bits(vc5->regmap, VC5_REF_DIVIDER, 0xff, div);
> +     regmap_update_bits(vc5->regmap, VC5_VCO_CTRL_AND_PREDIV,
> +                        VC5_VCO_CTRL_AND_PREDIV_BYPASS_PREDIV, 0);
> +
> +     return 0;
> +}
> +
> +static const struct clk_ops vc5_mux_ops = {
> +     .set_parent     = vc5_mux_set_parent,
> +     .get_parent     = vc5_mux_get_parent,
> +     .recalc_rate    = vc5_mux_recalc_rate,
> +     .round_rate     = vc5_mux_round_rate,
> +     .set_rate       = vc5_mux_set_rate,
> +};
> +
> +/*
> + * VersaClock5 PLL/VCO
> + */
> +static unsigned long vc5_pll_recalc_rate(struct clk_hw *hw,
> +                                      unsigned long parent_rate)
> +{
> +     struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
> +     struct vc5_driver_data *vc5 = hwdata->vc5;
> +     u32 div_int, div_frc;
> +     u8 fb[5];
> +
> +     regmap_bulk_read(vc5->regmap, 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 long vc5_pll_round_rate(struct clk_hw *hw, unsigned long rate,
> +                            unsigned long *parent_rate)
> +{
> +     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 int vc5_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> +                         unsigned long parent_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 regmap_bulk_write(vc5->regmap, VC5_FEEDBACK_INT_DIV, fb, 5);
> +}
> +
> +static const struct clk_ops vc5_pll_ops = {
> +     .recalc_rate    = vc5_pll_recalc_rate,
> +     .round_rate     = vc5_pll_round_rate,
> +     .set_rate       = vc5_pll_set_rate,
> +};
> +
> +static unsigned long vc5_fod_recalc_rate(struct clk_hw *hw,
> +                                      unsigned long parent_rate)
> +{
> +     struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
> +     struct vc5_driver_data *vc5 = hwdata->vc5;
> +     /* 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];
> +
> +     regmap_bulk_read(vc5->regmap, VC5_OUT_DIV_INT(hwdata->num, 0),
> +                      od_int, 2);
> +     regmap_bulk_read(vc5->regmap, 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);
> +
> +     /* 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 long vc5_fod_round_rate(struct clk_hw *hw, unsigned long rate,
> +                            unsigned long *parent_rate)
> +{
> +     struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
> +     /* 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 int vc5_fod_set_rate(struct clk_hw *hw, unsigned long rate,
> +                         unsigned long parent_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
> +     };
> +
> +     regmap_bulk_write(vc5->regmap, 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.
> +      */
> +     regmap_update_bits(vc5->regmap, VC5_GLOBAL_REGISTER,
> +                        VC5_GLOBAL_REGISTER_GLOBAL_RESET, 0);
> +     regmap_update_bits(vc5->regmap, VC5_GLOBAL_REGISTER,
> +                        VC5_GLOBAL_REGISTER_GLOBAL_RESET,
> +                        VC5_GLOBAL_REGISTER_GLOBAL_RESET);
> +     return 0;
> +}
> +
> +static const struct clk_ops vc5_fod_ops = {
> +     .recalc_rate    = vc5_fod_recalc_rate,
> +     .round_rate     = vc5_fod_round_rate,
> +     .set_rate       = vc5_fod_set_rate,
> +};
> +
> +static int vc5_clk_out_prepare(struct clk_hw *hw)
> +{
> +     struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
> +     struct vc5_driver_data *vc5 = hwdata->vc5;
> +
> +     /* Enable the clock buffer */
> +     regmap_update_bits(vc5->regmap, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
> +                        VC5_CLK_OUTPUT_CFG1_EN_CLKBUF,
> +                        VC5_CLK_OUTPUT_CFG1_EN_CLKBUF);
> +     return 0;
> +}
> +
> +static void vc5_clk_out_unprepare(struct clk_hw *hw)
> +{
> +     struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
> +     struct vc5_driver_data *vc5 = hwdata->vc5;
> +
> +     /* Enable the clock buffer */
> +     regmap_update_bits(vc5->regmap, VC5_CLK_OUTPUT_CFG(hwdata->num, 1),
> +                        VC5_CLK_OUTPUT_CFG1_EN_CLKBUF, 0);
> +}
> +
> +static unsigned char vc5_clk_out_get_parent(struct clk_hw *hw)
> +{
> +     struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
> +     struct vc5_driver_data *vc5 = hwdata->vc5;
> +     const u8 mask = VC5_OUT_DIV_CONTROL_SELB_NORM |
> +                     VC5_OUT_DIV_CONTROL_SEL_EXT |
> +                     VC5_OUT_DIV_CONTROL_EN_FOD;
> +     const u8 fodclkmask = VC5_OUT_DIV_CONTROL_SELB_NORM |
> +                           VC5_OUT_DIV_CONTROL_EN_FOD;
> +     const u8 extclk = VC5_OUT_DIV_CONTROL_SELB_NORM |
> +                       VC5_OUT_DIV_CONTROL_SEL_EXT;
> +     unsigned int src;
> +
> +     regmap_read(vc5->regmap, VC5_OUT_DIV_CONTROL(hwdata->num), &src);
> +     src &= mask;
> +
> +     if ((src & fodclkmask) == VC5_OUT_DIV_CONTROL_EN_FOD)
> +             return 0;
> +
> +     if (src == extclk)
> +             return 1;
> +
> +     dev_warn(&vc5->client->dev,
> +              "Invalid clock output configuration (%02x)\n", src);
> +     return 0;
> +}
> +
> +static int vc5_clk_out_set_parent(struct clk_hw *hw, u8 index)
> +{
> +     struct vc5_hw_data *hwdata = container_of(hw, struct vc5_hw_data, hw);
> +     struct vc5_driver_data *vc5 = hwdata->vc5;
> +     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 regmap_update_bits(vc5->regmap, VC5_OUT_DIV_CONTROL(hwdata->num),
> +                               mask, src);
> +}
> +
> +static const struct clk_ops vc5_clk_out_ops = {
> +     .prepare        = vc5_clk_out_prepare,
> +     .unprepare      = vc5_clk_out_unprepare,
> +     .set_parent     = vc5_clk_out_set_parent,
> +     .get_parent     = vc5_clk_out_get_parent,
> +};
> +
> +static struct clk_hw *
> +vc5_of_clk_get(struct of_phandle_args *clkspec, void *data)
> +{
> +     struct vc5_driver_data *vc5 = data;
> +     unsigned int idx = clkspec->args[0];
> +
> +     if (idx > 2) {
> +             pr_err("%s: invalid index %u\n", __func__, idx);
> +             return ERR_PTR(-EINVAL);
> +     }
> +
> +     return &vc5->clk_out[idx].hw;
> +}
> +
> +static int vc5_map_index_to_output(const enum vc5_model model,
> +                                const unsigned int n)
> +{
> +     switch (model) {
> +     case IDT_VC5_5P49V5923:
> +             if (n == 0)     /* OUT1 */
> +                     return 0;
> +             if (n == 1)     /* OUT2 */
> +                     return 1;
> +             break;
> +     case IDT_VC5_5P49V5933:
> +             if (n == 0)     /* OUT1 */
> +                     return 0;
> +             if (n == 1)     /* OUT4 */
> +                     return 3;
> +             break;
> +     }
> +
> +     /*
> +      * If we got here, there is certainly a bug in the driver,
> +      * but we shouldn't crash the kernel.
> +      */
> +     WARN_ON("Invalid clock index!\n");
> +     return -EINVAL;
> +}
> +
> +static const struct of_device_id clk_vc5_of_match[];
> +
> +static int vc5_probe(struct i2c_client *client,
> +                  const struct i2c_device_id *id)
> +{
> +     const struct of_device_id *of_id =
> +             of_match_device(clk_vc5_of_match, &client->dev);
> +     struct vc5_driver_data *vc5;
> +     struct clk_init_data init;
> +     const char *parent_names[2];
> +     unsigned int n, idx;
> +     int ret;
> +
> +     vc5 = devm_kzalloc(&client->dev, sizeof(*vc5), GFP_KERNEL);
> +     if (vc5 == NULL)
> +             return -ENOMEM;
> +
> +     i2c_set_clientdata(client, vc5);
> +     vc5->client = client;
> +     vc5->model = (enum vc5_model)of_id->data;
> +
> +     vc5->pin_xin = devm_clk_get(&client->dev, "xin");
> +     if (PTR_ERR(vc5->pin_xin) == -EPROBE_DEFER)
> +             return -EPROBE_DEFER;
> +
> +     vc5->pin_clkin = devm_clk_get(&client->dev, "clkin");
> +     if (PTR_ERR(vc5->pin_clkin) == -EPROBE_DEFER)
> +             return -EPROBE_DEFER;
> +
> +     vc5->regmap = devm_regmap_init_i2c(client, &vc5_regmap_config);
> +     if (IS_ERR(vc5->regmap)) {
> +             dev_err(&client->dev, "failed to allocate register map\n");
> +             return PTR_ERR(vc5->regmap);
> +     }
> +
> +     /* Register clock input mux */
> +     memset(&init, 0, sizeof(init));
> +
> +     if (!IS_ERR(vc5->pin_xin)) {
> +             clk_prepare_enable(vc5->pin_xin);
> +             vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
> +             parent_names[init.num_parents++] = __clk_get_name(vc5->pin_xin);
> +     } else if (vc5->model == IDT_VC5_5P49V5933) {
> +             /* IDT VC5 5P49V5933 has built-in oscilator. */
> +             vc5->pin_xin = clk_register_fixed_rate(&client->dev,
> +                                                    "internal-xtal", NULL,
> +                                                    0, 25000000);
> +             if (IS_ERR(vc5->pin_xin))
> +                     return PTR_ERR(vc5->pin_xin);
> +             vc5->clk_mux_ins |= VC5_MUX_IN_XIN;
> +             parent_names[init.num_parents++] = __clk_get_name(vc5->pin_xin);
> +     }
> +
> +     if (!IS_ERR(vc5->pin_clkin)) {
> +             clk_prepare_enable(vc5->pin_clkin);
> +             vc5->clk_mux_ins |= VC5_MUX_IN_CLKIN;
> +             parent_names[init.num_parents++] =
> +                     __clk_get_name(vc5->pin_clkin);
> +     }
> +
> +     if (!init.num_parents) {
> +             dev_err(&client->dev, "no input clock specified!\n");
> +             return -EINVAL;
> +     }
> +
> +     init.name = vc5_mux_names[0];
> +     init.ops = &vc5_mux_ops;
> +     init.flags = 0;
> +     init.parent_names = parent_names;
> +     vc5->clk_mux.init = &init;
> +     ret = devm_clk_hw_register(&client->dev, &vc5->clk_mux);
> +     if (ret) {
> +             dev_err(&client->dev, "unable to register %s\n", init.name);
> +             goto err_clk;
> +     }
> +
> +     /* Register PLL */
> +     memset(&init, 0, sizeof(init));
> +     init.name = vc5_pll_names[0];
> +     init.ops = &vc5_pll_ops;
> +     init.flags = CLK_SET_RATE_PARENT;
> +     init.parent_names = vc5_mux_names;
> +     init.num_parents = 1;
> +     vc5->clk_pll.num = 0;
> +     vc5->clk_pll.vc5 = vc5;
> +     vc5->clk_pll.hw.init = &init;
> +     ret = devm_clk_hw_register(&client->dev, &vc5->clk_pll.hw);
> +     if (ret) {
> +             dev_err(&client->dev, "unable to register %s\n", init.name);
> +             goto err_clk;
> +     }
> +
> +     /* Register FODs */
> +     for (n = 0; n < 2; n++) {
> +             idx = vc5_map_index_to_output(vc5->model, n);
> +             memset(&init, 0, sizeof(init));
> +             init.name = vc5_fod_names[idx];
> +             init.ops = &vc5_fod_ops;
> +             init.flags = CLK_SET_RATE_PARENT;
> +             init.parent_names = vc5_pll_names;
> +             init.num_parents = 1;
> +             vc5->clk_fod[n].num = idx;
> +             vc5->clk_fod[n].vc5 = vc5;
> +             vc5->clk_fod[n].hw.init = &init;
> +             ret = devm_clk_hw_register(&client->dev, &vc5->clk_fod[n].hw);
> +             if (ret) {
> +                     dev_err(&client->dev, "unable to register %s\n",
> +                             init.name);
> +                     goto err_clk;
> +             }
> +     }
> +
> +     /* Register MUX-connected OUT0_I2C_SELB output */
> +     memset(&init, 0, sizeof(init));
> +     init.name = vc5_clk_out_names[0];
> +     init.ops = &vc5_clk_out_ops;
> +     init.flags = CLK_SET_RATE_PARENT;
> +     init.parent_names = vc5_mux_names;
> +     init.num_parents = 1;
> +     vc5->clk_out[0].num = idx;
> +     vc5->clk_out[0].vc5 = vc5;
> +     vc5->clk_out[0].hw.init = &init;
> +     ret = devm_clk_hw_register(&client->dev, &vc5->clk_out[0].hw);
> +     if (ret) {
> +             dev_err(&client->dev, "unable to register %s\n",
> +                     init.name);
> +             goto err_clk;
> +     }
> +
> +     /* Register FOD-connected OUTx outputs */
> +     for (n = 1; n < 3; n++) {
> +             idx = vc5_map_index_to_output(vc5->model, n - 1);
> +             parent_names[0] = vc5_fod_names[idx];
> +             if (n == 1)
> +                     parent_names[1] = vc5_mux_names[0];
> +             else
> +                     parent_names[1] = vc5_clk_out_names[n - 1];
> +
> +             memset(&init, 0, sizeof(init));
> +             init.name = vc5_clk_out_names[idx + 1];
> +             init.ops = &vc5_clk_out_ops;
> +             init.flags = CLK_SET_RATE_PARENT;
> +             init.parent_names = parent_names;
> +             init.num_parents = 2;
> +             vc5->clk_out[n].num = idx;
> +             vc5->clk_out[n].vc5 = vc5;
> +             vc5->clk_out[n].hw.init = &init;
> +             ret = devm_clk_hw_register(&client->dev,
> +                                        &vc5->clk_out[n].hw);
> +             if (ret) {
> +                     dev_err(&client->dev, "unable to register %s\n",
> +                             init.name);
> +                     goto err_clk;
> +             }
> +     }
> +
> +     ret = of_clk_add_hw_provider(client->dev.of_node, vc5_of_clk_get, vc5);
> +     if (ret) {
> +             dev_err(&client->dev, "unable to add clk provider\n");
> +             goto err_clk;
> +     }
> +
> +     return 0;
> +
> +err_clk:
> +     if (!IS_ERR(vc5->pin_xin))
> +             clk_disable_unprepare(vc5->pin_xin);
> +     if (!IS_ERR(vc5->pin_clkin))
> +             clk_disable_unprepare(vc5->pin_clkin);
> +     if (vc5->model == IDT_VC5_5P49V5933)
> +             clk_unregister_fixed_rate(vc5->pin_xin);
> +     return ret;
> +}
> +
> +static int vc5_remove(struct i2c_client *client)
> +{
> +     struct vc5_driver_data *vc5 = i2c_get_clientdata(client);
> +
> +     of_clk_del_provider(client->dev.of_node);
> +
> +     if (vc5->clk_mux_ins & VC5_MUX_IN_XIN)
> +             clk_disable_unprepare(vc5->pin_xin);
> +
> +     if (vc5->clk_mux_ins & VC5_MUX_IN_CLKIN)
> +             clk_disable_unprepare(vc5->pin_clkin);
> +
> +     if (vc5->model == IDT_VC5_5P49V5933)
> +             clk_unregister_fixed_rate(vc5->pin_xin);
> +
> +     return 0;
> +}
> +
> +static const struct i2c_device_id vc5_id[] = {
> +     { "5p49v5923", .driver_data = IDT_VC5_5P49V5923 },
> +     { "5p49v5933", .driver_data = IDT_VC5_5P49V5933 },
> +     { }
> +};
> +MODULE_DEVICE_TABLE(i2c, vc5_id);
> +
> +static const struct of_device_id clk_vc5_of_match[] = {
> +     { .compatible = "idt,5p49v5923", .data = (void *)IDT_VC5_5P49V5923 },
> +     { .compatible = "idt,5p49v5933", .data = (void *)IDT_VC5_5P49V5933 },
> +     { },
> +};
> +
> +MODULE_DEVICE_TABLE(of, clk_vc5_of_match);
> +
> +static struct i2c_driver vc5_driver = {
> +     .driver = {
> +             .name = "vc5",
> +             .of_match_table = clk_vc5_of_match,
> +     },
> +     .probe          = vc5_probe,
> +     .remove         = vc5_remove,
> +     .id_table       = vc5_id,
> +};
> +
> +module_i2c_driver(vc5_driver);
> +
> +MODULE_AUTHOR("Marek Vasut <marek.va...@gmail.com>");
> +MODULE_DESCRIPTION("IDT VersaClock 5 driver");
> +MODULE_LICENSE("GPL");
> 


-- 
Best regards,
Marek Vasut

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