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linux-zen-server/drivers/clk/clk-versaclock7.c

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// SPDX-License-Identifier: GPL-2.0
/*
* Common clock framework driver for the Versaclock7 family of timing devices.
*
* Copyright (c) 2022 Renesas Electronics Corporation
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/i2c.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/regmap.h>
#include <linux/swab.h>
/*
* 16-bit register address: the lower 8 bits of the register address come
* from the offset addr byte and the upper 8 bits come from the page register.
*/
#define VC7_PAGE_ADDR 0xFD
#define VC7_PAGE_WINDOW 256
#define VC7_MAX_REG 0x364
/* Maximum number of banks supported by VC7 */
#define VC7_NUM_BANKS 7
/* Maximum number of FODs supported by VC7 */
#define VC7_NUM_FOD 3
/* Maximum number of IODs supported by VC7 */
#define VC7_NUM_IOD 4
/* Maximum number of outputs supported by VC7 */
#define VC7_NUM_OUT 12
/* VCO valid range is 9.5 GHz to 10.7 GHz */
#define VC7_APLL_VCO_MIN 9500000000UL
#define VC7_APLL_VCO_MAX 10700000000UL
/* APLL denominator is fixed at 2^27 */
#define VC7_APLL_DENOMINATOR_BITS 27
/* FOD 1st stage denominator is fixed 2^34 */
#define VC7_FOD_DENOMINATOR_BITS 34
/* IOD can operate between 1kHz and 650MHz */
#define VC7_IOD_RATE_MIN 1000UL
#define VC7_IOD_RATE_MAX 650000000UL
#define VC7_IOD_MIN_DIVISOR 14
#define VC7_IOD_MAX_DIVISOR 0x1ffffff /* 25-bit */
#define VC7_FOD_RATE_MIN 1000UL
#define VC7_FOD_RATE_MAX 650000000UL
#define VC7_FOD_1ST_STAGE_RATE_MIN 33000000UL /* 33 MHz */
#define VC7_FOD_1ST_STAGE_RATE_MAX 650000000UL /* 650 MHz */
#define VC7_FOD_1ST_INT_MAX 324
#define VC7_FOD_2ND_INT_MIN 2
#define VC7_FOD_2ND_INT_MAX 0x1ffff /* 17-bit */
/* VC7 Registers */
#define VC7_REG_XO_CNFG 0x2C
#define VC7_REG_XO_CNFG_COUNT 4
#define VC7_REG_XO_IB_H_DIV_SHIFT 24
#define VC7_REG_XO_IB_H_DIV_MASK GENMASK(28, VC7_REG_XO_IB_H_DIV_SHIFT)
#define VC7_REG_APLL_FB_DIV_FRAC 0x120
#define VC7_REG_APLL_FB_DIV_FRAC_COUNT 4
#define VC7_REG_APLL_FB_DIV_FRAC_MASK GENMASK(26, 0)
#define VC7_REG_APLL_FB_DIV_INT 0x124
#define VC7_REG_APLL_FB_DIV_INT_COUNT 2
#define VC7_REG_APLL_FB_DIV_INT_MASK GENMASK(9, 0)
#define VC7_REG_APLL_CNFG 0x127
#define VC7_REG_APLL_EN_DOUBLER BIT(0)
#define VC7_REG_OUT_BANK_CNFG(idx) (0x280 + (0x4 * (idx)))
#define VC7_REG_OUTPUT_BANK_SRC_MASK GENMASK(2, 0)
#define VC7_REG_FOD_INT_CNFG(idx) (0x1E0 + (0x10 * (idx)))
#define VC7_REG_FOD_INT_CNFG_COUNT 8
#define VC7_REG_FOD_1ST_INT_MASK GENMASK(8, 0)
#define VC7_REG_FOD_2ND_INT_SHIFT 9
#define VC7_REG_FOD_2ND_INT_MASK GENMASK(25, VC7_REG_FOD_2ND_INT_SHIFT)
#define VC7_REG_FOD_FRAC_SHIFT 26
#define VC7_REG_FOD_FRAC_MASK GENMASK_ULL(59, VC7_REG_FOD_FRAC_SHIFT)
#define VC7_REG_IOD_INT_CNFG(idx) (0x1C0 + (0x8 * (idx)))
#define VC7_REG_IOD_INT_CNFG_COUNT 4
#define VC7_REG_IOD_INT_MASK GENMASK(24, 0)
#define VC7_REG_ODRV_EN(idx) (0x240 + (0x4 * (idx)))
#define VC7_REG_OUT_DIS BIT(0)
struct vc7_driver_data;
static const struct regmap_config vc7_regmap_config;
/* Supported Renesas VC7 models */
enum vc7_model {
VC7_RC21008A,
};
struct vc7_chip_info {
const enum vc7_model model;
const unsigned int banks[VC7_NUM_BANKS];
const unsigned int num_banks;
const unsigned int outputs[VC7_NUM_OUT];
const unsigned int num_outputs;
};
/*
* Changing the APLL frequency is currently not supported.
* The APLL will consist of an opaque block between the XO and FOD/IODs and
* its frequency will be computed based on the current state of the device.
*/
struct vc7_apll_data {
struct clk *clk;
struct vc7_driver_data *vc7;
u8 xo_ib_h_div;
u8 en_doubler;
u16 apll_fb_div_int;
u32 apll_fb_div_frac;
};
struct vc7_fod_data {
struct clk_hw hw;
struct vc7_driver_data *vc7;
unsigned int num;
u32 fod_1st_int;
u32 fod_2nd_int;
u64 fod_frac;
};
struct vc7_iod_data {
struct clk_hw hw;
struct vc7_driver_data *vc7;
unsigned int num;
u32 iod_int;
};
struct vc7_out_data {
struct clk_hw hw;
struct vc7_driver_data *vc7;
unsigned int num;
unsigned int out_dis;
};
struct vc7_driver_data {
struct i2c_client *client;
struct regmap *regmap;
const struct vc7_chip_info *chip_info;
struct clk *pin_xin;
struct vc7_apll_data clk_apll;
struct vc7_fod_data clk_fod[VC7_NUM_FOD];
struct vc7_iod_data clk_iod[VC7_NUM_IOD];
struct vc7_out_data clk_out[VC7_NUM_OUT];
};
struct vc7_bank_src_map {
enum vc7_bank_src_type {
VC7_FOD,
VC7_IOD,
} type;
union _divider {
struct vc7_iod_data *iod;
struct vc7_fod_data *fod;
} src;
};
static struct clk_hw *vc7_of_clk_get(struct of_phandle_args *clkspec,
void *data)
{
struct vc7_driver_data *vc7 = data;
unsigned int idx = clkspec->args[0];
if (idx >= vc7->chip_info->num_outputs)
return ERR_PTR(-EINVAL);
return &vc7->clk_out[idx].hw;
}
static const unsigned int RC21008A_index_to_output_mapping[] = {
1, 2, 3, 6, 7, 8, 10, 11
};
static int vc7_map_index_to_output(const enum vc7_model model, const unsigned int i)
{
switch (model) {
case VC7_RC21008A:
return RC21008A_index_to_output_mapping[i];
default:
return i;
}
}
/* bank to output mapping, same across all variants */
static const unsigned int output_bank_mapping[] = {
0, /* Output 0 */
1, /* Output 1 */
2, /* Output 2 */
2, /* Output 3 */
3, /* Output 4 */
3, /* Output 5 */
3, /* Output 6 */
3, /* Output 7 */
4, /* Output 8 */
4, /* Output 9 */
5, /* Output 10 */
6 /* Output 11 */
};
/**
* vc7_64_mul_64_to_128() - Multiply two u64 and return an unsigned 128-bit integer
* as an upper and lower part.
*
* @left: The left argument.
* @right: The right argument.
* @hi: The upper 64-bits of the 128-bit product.
* @lo: The lower 64-bits of the 128-bit product.
*
* From mul_64_64 in crypto/ecc.c:350 in the linux kernel, accessed in v5.17.2.
*/
static void vc7_64_mul_64_to_128(u64 left, u64 right, u64 *hi, u64 *lo)
{
u64 a0 = left & 0xffffffffull;
u64 a1 = left >> 32;
u64 b0 = right & 0xffffffffull;
u64 b1 = right >> 32;
u64 m0 = a0 * b0;
u64 m1 = a0 * b1;
u64 m2 = a1 * b0;
u64 m3 = a1 * b1;
m2 += (m0 >> 32);
m2 += m1;
/* Overflow */
if (m2 < m1)
m3 += 0x100000000ull;
*lo = (m0 & 0xffffffffull) | (m2 << 32);
*hi = m3 + (m2 >> 32);
}
/**
* vc7_128_div_64_to_64() - Divides a 128-bit uint by a 64-bit divisor, return a 64-bit quotient.
*
* @numhi: The uppper 64-bits of the dividend.
* @numlo: The lower 64-bits of the dividend.
* @den: The denominator (divisor).
* @r: The remainder, pass NULL if the remainder is not needed.
*
* Originally from libdivide, modified to use kernel u64/u32 types.
*
* See https://github.com/ridiculousfish/libdivide/blob/master/libdivide.h#L471.
*
* Return: The 64-bit quotient of the division.
*
* In case of overflow of division by zero, max(u64) is returned.
*/
static u64 vc7_128_div_64_to_64(u64 numhi, u64 numlo, u64 den, u64 *r)
{
/*
* We work in base 2**32.
* A uint32 holds a single digit. A uint64 holds two digits.
* Our numerator is conceptually [num3, num2, num1, num0].
* Our denominator is [den1, den0].
*/
const u64 b = ((u64)1 << 32);
/* The high and low digits of our computed quotient. */
u32 q1, q0;
/* The normalization shift factor */
int shift;
/*
* The high and low digits of our denominator (after normalizing).
* Also the low 2 digits of our numerator (after normalizing).
*/
u32 den1, den0, num1, num0;
/* A partial remainder; */
u64 rem;
/*
* The estimated quotient, and its corresponding remainder (unrelated
* to true remainder).
*/
u64 qhat, rhat;
/* Variables used to correct the estimated quotient. */
u64 c1, c2;
/* Check for overflow and divide by 0. */
if (numhi >= den) {
if (r)
*r = ~0ull;
return ~0ull;
}
/*
* Determine the normalization factor. We multiply den by this, so that
* its leading digit is at least half b. In binary this means just
* shifting left by the number of leading zeros, so that there's a 1 in
* the MSB.
*
* We also shift numer by the same amount. This cannot overflow because
* numhi < den. The expression (-shift & 63) is the same as (64 -
* shift), except it avoids the UB of shifting by 64. The funny bitwise
* 'and' ensures that numlo does not get shifted into numhi if shift is
* 0. clang 11 has an x86 codegen bug here: see LLVM bug 50118. The
* sequence below avoids it.
*/
shift = __builtin_clzll(den);
den <<= shift;
numhi <<= shift;
numhi |= (numlo >> (-shift & 63)) & (-(s64)shift >> 63);
numlo <<= shift;
/*
* Extract the low digits of the numerator and both digits of the
* denominator.
*/
num1 = (u32)(numlo >> 32);
num0 = (u32)(numlo & 0xFFFFFFFFu);
den1 = (u32)(den >> 32);
den0 = (u32)(den & 0xFFFFFFFFu);
/*
* We wish to compute q1 = [n3 n2 n1] / [d1 d0].
* Estimate q1 as [n3 n2] / [d1], and then correct it.
* Note while qhat may be 2 digits, q1 is always 1 digit.
*/
qhat = div64_u64_rem(numhi, den1, &rhat);
c1 = qhat * den0;
c2 = rhat * b + num1;
if (c1 > c2)
qhat -= (c1 - c2 > den) ? 2 : 1;
q1 = (u32)qhat;
/* Compute the true (partial) remainder. */
rem = numhi * b + num1 - q1 * den;
/*
* We wish to compute q0 = [rem1 rem0 n0] / [d1 d0].
* Estimate q0 as [rem1 rem0] / [d1] and correct it.
*/
qhat = div64_u64_rem(rem, den1, &rhat);
c1 = qhat * den0;
c2 = rhat * b + num0;
if (c1 > c2)
qhat -= (c1 - c2 > den) ? 2 : 1;
q0 = (u32)qhat;
/* Return remainder if requested. */
if (r)
*r = (rem * b + num0 - q0 * den) >> shift;
return ((u64)q1 << 32) | q0;
}
static int vc7_get_bank_clk(struct vc7_driver_data *vc7,
unsigned int bank_idx,
unsigned int output_bank_src,
struct vc7_bank_src_map *map)
{
/* Mapping from Table 38 in datasheet */
if (bank_idx == 0 || bank_idx == 1) {
switch (output_bank_src) {
case 0:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[0];
return 0;
case 1:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[1];
return 0;
case 4:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[0];
return 0;
case 5:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[1];
return 0;
default:
break;
}
} else if (bank_idx == 2) {
switch (output_bank_src) {
case 1:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[1];
return 0;
case 4:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[0];
return 0;
case 5:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[1];
return 0;
default:
break;
}
} else if (bank_idx == 3) {
switch (output_bank_src) {
case 4:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[0];
return 0;
case 5:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[1];
return 0;
case 6:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[2];
return 0;
default:
break;
}
} else if (bank_idx == 4) {
switch (output_bank_src) {
case 0:
/* CLKIN1 not supported in this driver */
break;
case 2:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[2];
return 0;
case 5:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[1];
return 0;
case 6:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[2];
return 0;
case 7:
/* CLKIN0 not supported in this driver */
break;
default:
break;
}
} else if (bank_idx == 5) {
switch (output_bank_src) {
case 0:
/* CLKIN1 not supported in this driver */
break;
case 1:
/* XIN_REFIN not supported in this driver */
break;
case 2:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[2];
return 0;
case 3:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[3];
return 0;
case 5:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[1];
return 0;
case 6:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[2];
return 0;
case 7:
/* CLKIN0 not supported in this driver */
break;
default:
break;
}
} else if (bank_idx == 6) {
switch (output_bank_src) {
case 0:
/* CLKIN1 not supported in this driver */
break;
case 2:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[2];
return 0;
case 3:
map->type = VC7_IOD,
map->src.iod = &vc7->clk_iod[3];
return 0;
case 5:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[1];
return 0;
case 6:
map->type = VC7_FOD,
map->src.fod = &vc7->clk_fod[2];
return 0;
case 7:
/* CLKIN0 not supported in this driver */
break;
default:
break;
}
}
pr_warn("bank_src%d = %d is not supported\n", bank_idx, output_bank_src);
return -1;
}
static int vc7_read_apll(struct vc7_driver_data *vc7)
{
int err;
u32 val32;
u16 val16;
err = regmap_bulk_read(vc7->regmap,
VC7_REG_XO_CNFG,
(u32 *)&val32,
VC7_REG_XO_CNFG_COUNT);
if (err) {
dev_err(&vc7->client->dev, "failed to read XO_CNFG\n");
return err;
}
vc7->clk_apll.xo_ib_h_div = (val32 & VC7_REG_XO_IB_H_DIV_MASK)
>> VC7_REG_XO_IB_H_DIV_SHIFT;
err = regmap_read(vc7->regmap,
VC7_REG_APLL_CNFG,
&val32);
if (err) {
dev_err(&vc7->client->dev, "failed to read APLL_CNFG\n");
return err;
}
vc7->clk_apll.en_doubler = val32 & VC7_REG_APLL_EN_DOUBLER;
err = regmap_bulk_read(vc7->regmap,
VC7_REG_APLL_FB_DIV_FRAC,
(u32 *)&val32,
VC7_REG_APLL_FB_DIV_FRAC_COUNT);
if (err) {
dev_err(&vc7->client->dev, "failed to read APLL_FB_DIV_FRAC\n");
return err;
}
vc7->clk_apll.apll_fb_div_frac = val32 & VC7_REG_APLL_FB_DIV_FRAC_MASK;
err = regmap_bulk_read(vc7->regmap,
VC7_REG_APLL_FB_DIV_INT,
(u16 *)&val16,
VC7_REG_APLL_FB_DIV_INT_COUNT);
if (err) {
dev_err(&vc7->client->dev, "failed to read APLL_FB_DIV_INT\n");
return err;
}
vc7->clk_apll.apll_fb_div_int = val16 & VC7_REG_APLL_FB_DIV_INT_MASK;
return 0;
}
static int vc7_read_fod(struct vc7_driver_data *vc7, unsigned int idx)
{
int err;
u64 val;
err = regmap_bulk_read(vc7->regmap,
VC7_REG_FOD_INT_CNFG(idx),
(u64 *)&val,
VC7_REG_FOD_INT_CNFG_COUNT);
if (err) {
dev_err(&vc7->client->dev, "failed to read FOD%d\n", idx);
return err;
}
vc7->clk_fod[idx].fod_1st_int = (val & VC7_REG_FOD_1ST_INT_MASK);
vc7->clk_fod[idx].fod_2nd_int =
(val & VC7_REG_FOD_2ND_INT_MASK) >> VC7_REG_FOD_2ND_INT_SHIFT;
vc7->clk_fod[idx].fod_frac = (val & VC7_REG_FOD_FRAC_MASK)
>> VC7_REG_FOD_FRAC_SHIFT;
return 0;
}
static int vc7_write_fod(struct vc7_driver_data *vc7, unsigned int idx)
{
int err;
u64 val;
/*
* FOD dividers are part of an atomic group where fod_1st_int,
* fod_2nd_int, and fod_frac must be written together. The new divider
* is applied when the MSB of fod_frac is written.
*/
err = regmap_bulk_read(vc7->regmap,
VC7_REG_FOD_INT_CNFG(idx),
(u64 *)&val,
VC7_REG_FOD_INT_CNFG_COUNT);
if (err) {
dev_err(&vc7->client->dev, "failed to read FOD%d\n", idx);
return err;
}
val = u64_replace_bits(val,
vc7->clk_fod[idx].fod_1st_int,
VC7_REG_FOD_1ST_INT_MASK);
val = u64_replace_bits(val,
vc7->clk_fod[idx].fod_2nd_int,
VC7_REG_FOD_2ND_INT_MASK);
val = u64_replace_bits(val,
vc7->clk_fod[idx].fod_frac,
VC7_REG_FOD_FRAC_MASK);
err = regmap_bulk_write(vc7->regmap,
VC7_REG_FOD_INT_CNFG(idx),
(u64 *)&val,
sizeof(u64));
if (err) {
dev_err(&vc7->client->dev, "failed to write FOD%d\n", idx);
return err;
}
return 0;
}
static int vc7_read_iod(struct vc7_driver_data *vc7, unsigned int idx)
{
int err;
u32 val;
err = regmap_bulk_read(vc7->regmap,
VC7_REG_IOD_INT_CNFG(idx),
(u32 *)&val,
VC7_REG_IOD_INT_CNFG_COUNT);
if (err) {
dev_err(&vc7->client->dev, "failed to read IOD%d\n", idx);
return err;
}
vc7->clk_iod[idx].iod_int = (val & VC7_REG_IOD_INT_MASK);
return 0;
}
static int vc7_write_iod(struct vc7_driver_data *vc7, unsigned int idx)
{
int err;
u32 val;
/*
* IOD divider field is atomic and all bits must be written.
* The new divider is applied when the MSB of iod_int is written.
*/
err = regmap_bulk_read(vc7->regmap,
VC7_REG_IOD_INT_CNFG(idx),
(u32 *)&val,
VC7_REG_IOD_INT_CNFG_COUNT);
if (err) {
dev_err(&vc7->client->dev, "failed to read IOD%d\n", idx);
return err;
}
val = u32_replace_bits(val,
vc7->clk_iod[idx].iod_int,
VC7_REG_IOD_INT_MASK);
err = regmap_bulk_write(vc7->regmap,
VC7_REG_IOD_INT_CNFG(idx),
(u32 *)&val,
sizeof(u32));
if (err) {
dev_err(&vc7->client->dev, "failed to write IOD%d\n", idx);
return err;
}
return 0;
}
static int vc7_read_output(struct vc7_driver_data *vc7, unsigned int idx)
{
int err;
unsigned int val, out_num;
out_num = vc7_map_index_to_output(vc7->chip_info->model, idx);
err = regmap_read(vc7->regmap,
VC7_REG_ODRV_EN(out_num),
&val);
if (err) {
dev_err(&vc7->client->dev, "failed to read ODRV_EN[%d]\n", idx);
return err;
}
vc7->clk_out[idx].out_dis = val & VC7_REG_OUT_DIS;
return 0;
}
static int vc7_write_output(struct vc7_driver_data *vc7, unsigned int idx)
{
int err;
unsigned int out_num;
out_num = vc7_map_index_to_output(vc7->chip_info->model, idx);
err = regmap_write_bits(vc7->regmap,
VC7_REG_ODRV_EN(out_num),
VC7_REG_OUT_DIS,
vc7->clk_out[idx].out_dis);
if (err) {
dev_err(&vc7->client->dev, "failed to write ODRV_EN[%d]\n", idx);
return err;
}
return 0;
}
static unsigned long vc7_get_apll_rate(struct vc7_driver_data *vc7)
{
int err;
unsigned long xtal_rate;
u64 refin_div, apll_rate;
xtal_rate = clk_get_rate(vc7->pin_xin);
err = vc7_read_apll(vc7);
if (err) {
dev_err(&vc7->client->dev, "unable to read apll\n");
return err;
}
/* 0 is bypassed, 1 is reserved */
if (vc7->clk_apll.xo_ib_h_div < 2)
refin_div = xtal_rate;
else
refin_div = div64_u64(xtal_rate, vc7->clk_apll.xo_ib_h_div);
if (vc7->clk_apll.en_doubler)
refin_div *= 2;
/* divider = int + (frac / 2^27) */
apll_rate = (refin_div * vc7->clk_apll.apll_fb_div_int) +
((refin_div * vc7->clk_apll.apll_fb_div_frac) >> VC7_APLL_DENOMINATOR_BITS);
pr_debug("%s - xo_ib_h_div: %u, apll_fb_div_int: %u, apll_fb_div_frac: %u\n",
__func__, vc7->clk_apll.xo_ib_h_div, vc7->clk_apll.apll_fb_div_int,
vc7->clk_apll.apll_fb_div_frac);
pr_debug("%s - refin_div: %llu, apll rate: %llu\n",
__func__, refin_div, apll_rate);
return apll_rate;
}
static void vc7_calc_iod_divider(unsigned long rate, unsigned long parent_rate,
u32 *divider)
{
*divider = DIV_ROUND_UP(parent_rate, rate);
if (*divider < VC7_IOD_MIN_DIVISOR)
*divider = VC7_IOD_MIN_DIVISOR;
if (*divider > VC7_IOD_MAX_DIVISOR)
*divider = VC7_IOD_MAX_DIVISOR;
}
static void vc7_calc_fod_1st_stage(unsigned long rate, unsigned long parent_rate,
u32 *div_int, u64 *div_frac)
{
u64 rem;
*div_int = (u32)div64_u64_rem(parent_rate, rate, &rem);
*div_frac = div64_u64(rem << VC7_FOD_DENOMINATOR_BITS, rate);
}
static unsigned long vc7_calc_fod_1st_stage_rate(unsigned long parent_rate,
u32 fod_1st_int, u64 fod_frac)
{
u64 numer, denom, hi, lo, divisor;
numer = fod_frac;
denom = BIT_ULL(VC7_FOD_DENOMINATOR_BITS);
if (fod_frac) {
vc7_64_mul_64_to_128(parent_rate, denom, &hi, &lo);
divisor = ((u64)fod_1st_int * denom) + numer;
return vc7_128_div_64_to_64(hi, lo, divisor, NULL);
}
return div64_u64(parent_rate, fod_1st_int);
}
static unsigned long vc7_calc_fod_2nd_stage_rate(unsigned long parent_rate,
u32 fod_1st_int, u32 fod_2nd_int, u64 fod_frac)
{
unsigned long fod_1st_stage_rate;
fod_1st_stage_rate = vc7_calc_fod_1st_stage_rate(parent_rate, fod_1st_int, fod_frac);
if (fod_2nd_int < 2)
return fod_1st_stage_rate;
/*
* There is a div-by-2 preceding the 2nd stage integer divider
* (not shown on block diagram) so the actual 2nd stage integer
* divisor is 2 * N.
*/
return div64_u64(fod_1st_stage_rate >> 1, fod_2nd_int);
}
static void vc7_calc_fod_divider(unsigned long rate, unsigned long parent_rate,
u32 *fod_1st_int, u32 *fod_2nd_int, u64 *fod_frac)
{
unsigned int allow_frac, i, best_frac_i;
unsigned long first_stage_rate;
vc7_calc_fod_1st_stage(rate, parent_rate, fod_1st_int, fod_frac);
first_stage_rate = vc7_calc_fod_1st_stage_rate(parent_rate, *fod_1st_int, *fod_frac);
*fod_2nd_int = 0;
/* Do we need the second stage integer divider? */
if (first_stage_rate < VC7_FOD_1ST_STAGE_RATE_MIN) {
allow_frac = 0;
best_frac_i = VC7_FOD_2ND_INT_MIN;
for (i = VC7_FOD_2ND_INT_MIN; i <= VC7_FOD_2ND_INT_MAX; i++) {
/*
* 1) There is a div-by-2 preceding the 2nd stage integer divider
* (not shown on block diagram) so the actual 2nd stage integer
* divisor is 2 * N.
* 2) Attempt to find an integer solution first. This means stepping
* through each 2nd stage integer and recalculating the 1st stage
* until the 1st stage frequency is out of bounds. If no integer
* solution is found, use the best fractional solution.
*/
vc7_calc_fod_1st_stage(parent_rate, rate * 2 * i, fod_1st_int, fod_frac);
first_stage_rate = vc7_calc_fod_1st_stage_rate(parent_rate,
*fod_1st_int,
*fod_frac);
/* Remember the first viable fractional solution */
if (best_frac_i == VC7_FOD_2ND_INT_MIN &&
first_stage_rate > VC7_FOD_1ST_STAGE_RATE_MIN) {
best_frac_i = i;
}
/* Is the divider viable? Prefer integer solutions over fractional. */
if (*fod_1st_int < VC7_FOD_1ST_INT_MAX &&
first_stage_rate >= VC7_FOD_1ST_STAGE_RATE_MIN &&
(allow_frac || *fod_frac == 0)) {
*fod_2nd_int = i;
break;
}
/* Ran out of divisors or the 1st stage frequency is out of range */
if (i >= VC7_FOD_2ND_INT_MAX ||
first_stage_rate > VC7_FOD_1ST_STAGE_RATE_MAX) {
allow_frac = 1;
i = best_frac_i;
/* Restore the best frac and rerun the loop for the last time */
if (best_frac_i != VC7_FOD_2ND_INT_MIN)
i--;
continue;
}
}
}
}
static unsigned long vc7_fod_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
struct vc7_fod_data *fod = container_of(hw, struct vc7_fod_data, hw);
struct vc7_driver_data *vc7 = fod->vc7;
int err;
unsigned long fod_rate;
err = vc7_read_fod(vc7, fod->num);
if (err) {
dev_err(&vc7->client->dev, "error reading registers for %s\n",
clk_hw_get_name(hw));
return err;
}
pr_debug("%s - %s: parent_rate: %lu\n", __func__, clk_hw_get_name(hw), parent_rate);
fod_rate = vc7_calc_fod_2nd_stage_rate(parent_rate, fod->fod_1st_int,
fod->fod_2nd_int, fod->fod_frac);
pr_debug("%s - %s: fod_1st_int: %u, fod_2nd_int: %u, fod_frac: %llu\n",
__func__, clk_hw_get_name(hw),
fod->fod_1st_int, fod->fod_2nd_int, fod->fod_frac);
pr_debug("%s - %s rate: %lu\n", __func__, clk_hw_get_name(hw), fod_rate);
return fod_rate;
}
static long vc7_fod_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate)
{
struct vc7_fod_data *fod = container_of(hw, struct vc7_fod_data, hw);
unsigned long fod_rate;
pr_debug("%s - %s: requested rate: %lu, parent_rate: %lu\n",
__func__, clk_hw_get_name(hw), rate, *parent_rate);
vc7_calc_fod_divider(rate, *parent_rate,
&fod->fod_1st_int, &fod->fod_2nd_int, &fod->fod_frac);
fod_rate = vc7_calc_fod_2nd_stage_rate(*parent_rate, fod->fod_1st_int,
fod->fod_2nd_int, fod->fod_frac);
pr_debug("%s - %s: fod_1st_int: %u, fod_2nd_int: %u, fod_frac: %llu\n",
__func__, clk_hw_get_name(hw),
fod->fod_1st_int, fod->fod_2nd_int, fod->fod_frac);
pr_debug("%s - %s rate: %lu\n", __func__, clk_hw_get_name(hw), fod_rate);
return fod_rate;
}
static int vc7_fod_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate)
{
struct vc7_fod_data *fod = container_of(hw, struct vc7_fod_data, hw);
struct vc7_driver_data *vc7 = fod->vc7;
unsigned long fod_rate;
pr_debug("%s - %s: rate: %lu, parent_rate: %lu\n",
__func__, clk_hw_get_name(hw), rate, parent_rate);
if (rate < VC7_FOD_RATE_MIN || rate > VC7_FOD_RATE_MAX) {
dev_err(&vc7->client->dev,
"requested frequency %lu Hz for %s is out of range\n",
rate, clk_hw_get_name(hw));
return -EINVAL;
}
vc7_write_fod(vc7, fod->num);
fod_rate = vc7_calc_fod_2nd_stage_rate(parent_rate, fod->fod_1st_int,
fod->fod_2nd_int, fod->fod_frac);
pr_debug("%s - %s: fod_1st_int: %u, fod_2nd_int: %u, fod_frac: %llu\n",
__func__, clk_hw_get_name(hw),
fod->fod_1st_int, fod->fod_2nd_int, fod->fod_frac);
pr_debug("%s - %s rate: %lu\n", __func__, clk_hw_get_name(hw), fod_rate);
return 0;
}
static const struct clk_ops vc7_fod_ops = {
.recalc_rate = vc7_fod_recalc_rate,
.round_rate = vc7_fod_round_rate,
.set_rate = vc7_fod_set_rate,
};
static unsigned long vc7_iod_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
struct vc7_iod_data *iod = container_of(hw, struct vc7_iod_data, hw);
struct vc7_driver_data *vc7 = iod->vc7;
int err;
unsigned long iod_rate;
err = vc7_read_iod(vc7, iod->num);
if (err) {
dev_err(&vc7->client->dev, "error reading registers for %s\n",
clk_hw_get_name(hw));
return err;
}
iod_rate = div64_u64(parent_rate, iod->iod_int);
pr_debug("%s - %s: iod_int: %u\n", __func__, clk_hw_get_name(hw), iod->iod_int);
pr_debug("%s - %s rate: %lu\n", __func__, clk_hw_get_name(hw), iod_rate);
return iod_rate;
}
static long vc7_iod_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *parent_rate)
{
struct vc7_iod_data *iod = container_of(hw, struct vc7_iod_data, hw);
unsigned long iod_rate;
pr_debug("%s - %s: requested rate: %lu, parent_rate: %lu\n",
__func__, clk_hw_get_name(hw), rate, *parent_rate);
vc7_calc_iod_divider(rate, *parent_rate, &iod->iod_int);
iod_rate = div64_u64(*parent_rate, iod->iod_int);
pr_debug("%s - %s: iod_int: %u\n", __func__, clk_hw_get_name(hw), iod->iod_int);
pr_debug("%s - %s rate: %ld\n", __func__, clk_hw_get_name(hw), iod_rate);
return iod_rate;
}
static int vc7_iod_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate)
{
struct vc7_iod_data *iod = container_of(hw, struct vc7_iod_data, hw);
struct vc7_driver_data *vc7 = iod->vc7;
unsigned long iod_rate;
pr_debug("%s - %s: rate: %lu, parent_rate: %lu\n",
__func__, clk_hw_get_name(hw), rate, parent_rate);
if (rate < VC7_IOD_RATE_MIN || rate > VC7_IOD_RATE_MAX) {
dev_err(&vc7->client->dev,
"requested frequency %lu Hz for %s is out of range\n",
rate, clk_hw_get_name(hw));
return -EINVAL;
}
vc7_write_iod(vc7, iod->num);
iod_rate = div64_u64(parent_rate, iod->iod_int);
pr_debug("%s - %s: iod_int: %u\n", __func__, clk_hw_get_name(hw), iod->iod_int);
pr_debug("%s - %s rate: %ld\n", __func__, clk_hw_get_name(hw), iod_rate);
return 0;
}
static const struct clk_ops vc7_iod_ops = {
.recalc_rate = vc7_iod_recalc_rate,
.round_rate = vc7_iod_round_rate,
.set_rate = vc7_iod_set_rate,
};
static int vc7_clk_out_prepare(struct clk_hw *hw)
{
struct vc7_out_data *out = container_of(hw, struct vc7_out_data, hw);
struct vc7_driver_data *vc7 = out->vc7;
int err;
out->out_dis = 0;
err = vc7_write_output(vc7, out->num);
if (err) {
dev_err(&vc7->client->dev, "error writing registers for %s\n",
clk_hw_get_name(hw));
return err;
}
pr_debug("%s - %s: clk prepared\n", __func__, clk_hw_get_name(hw));
return 0;
}
static void vc7_clk_out_unprepare(struct clk_hw *hw)
{
struct vc7_out_data *out = container_of(hw, struct vc7_out_data, hw);
struct vc7_driver_data *vc7 = out->vc7;
int err;
out->out_dis = 1;
err = vc7_write_output(vc7, out->num);
if (err) {
dev_err(&vc7->client->dev, "error writing registers for %s\n",
clk_hw_get_name(hw));
return;
}
pr_debug("%s - %s: clk unprepared\n", __func__, clk_hw_get_name(hw));
}
static int vc7_clk_out_is_enabled(struct clk_hw *hw)
{
struct vc7_out_data *out = container_of(hw, struct vc7_out_data, hw);
struct vc7_driver_data *vc7 = out->vc7;
int err, is_enabled;
err = vc7_read_output(vc7, out->num);
if (err) {
dev_err(&vc7->client->dev, "error reading registers for %s\n",
clk_hw_get_name(hw));
return err;
}
is_enabled = !out->out_dis;
pr_debug("%s - %s: is_enabled=%d\n", __func__, clk_hw_get_name(hw), is_enabled);
return is_enabled;
}
static const struct clk_ops vc7_clk_out_ops = {
.prepare = vc7_clk_out_prepare,
.unprepare = vc7_clk_out_unprepare,
.is_enabled = vc7_clk_out_is_enabled,
};
static int vc7_probe(struct i2c_client *client)
{
struct vc7_driver_data *vc7;
struct clk_init_data clk_init;
struct vc7_bank_src_map bank_src_map;
const char *node_name, *apll_name;
const char *parent_names[1];
unsigned int i, val, bank_idx, out_num;
unsigned long apll_rate;
int ret;
vc7 = devm_kzalloc(&client->dev, sizeof(*vc7), GFP_KERNEL);
if (!vc7)
return -ENOMEM;
i2c_set_clientdata(client, vc7);
vc7->client = client;
vc7->chip_info = of_device_get_match_data(&client->dev);
vc7->pin_xin = devm_clk_get(&client->dev, "xin");
if (PTR_ERR(vc7->pin_xin) == -EPROBE_DEFER) {
return dev_err_probe(&client->dev, -EPROBE_DEFER,
"xin not specified\n");
}
vc7->regmap = devm_regmap_init_i2c(client, &vc7_regmap_config);
if (IS_ERR(vc7->regmap)) {
return dev_err_probe(&client->dev, PTR_ERR(vc7->regmap),
"failed to allocate register map\n");
}
if (of_property_read_string(client->dev.of_node, "clock-output-names",
&node_name))
node_name = client->dev.of_node->name;
/* Register APLL */
apll_rate = vc7_get_apll_rate(vc7);
apll_name = kasprintf(GFP_KERNEL, "%s_apll", node_name);
vc7->clk_apll.clk = clk_register_fixed_rate(&client->dev, apll_name,
__clk_get_name(vc7->pin_xin),
0, apll_rate);
kfree(apll_name); /* ccf made a copy of the name */
if (IS_ERR(vc7->clk_apll.clk)) {
return dev_err_probe(&client->dev, PTR_ERR(vc7->clk_apll.clk),
"failed to register apll\n");
}
/* Register FODs */
for (i = 0; i < VC7_NUM_FOD; i++) {
memset(&clk_init, 0, sizeof(clk_init));
clk_init.name = kasprintf(GFP_KERNEL, "%s_fod%d", node_name, i);
clk_init.ops = &vc7_fod_ops;
clk_init.parent_names = parent_names;
parent_names[0] = __clk_get_name(vc7->clk_apll.clk);
clk_init.num_parents = 1;
vc7->clk_fod[i].num = i;
vc7->clk_fod[i].vc7 = vc7;
vc7->clk_fod[i].hw.init = &clk_init;
ret = devm_clk_hw_register(&client->dev, &vc7->clk_fod[i].hw);
if (ret)
goto err_clk_register;
kfree(clk_init.name); /* ccf made a copy of the name */
}
/* Register IODs */
for (i = 0; i < VC7_NUM_IOD; i++) {
memset(&clk_init, 0, sizeof(clk_init));
clk_init.name = kasprintf(GFP_KERNEL, "%s_iod%d", node_name, i);
clk_init.ops = &vc7_iod_ops;
clk_init.parent_names = parent_names;
parent_names[0] = __clk_get_name(vc7->clk_apll.clk);
clk_init.num_parents = 1;
vc7->clk_iod[i].num = i;
vc7->clk_iod[i].vc7 = vc7;
vc7->clk_iod[i].hw.init = &clk_init;
ret = devm_clk_hw_register(&client->dev, &vc7->clk_iod[i].hw);
if (ret)
goto err_clk_register;
kfree(clk_init.name); /* ccf made a copy of the name */
}
/* Register outputs */
for (i = 0; i < vc7->chip_info->num_outputs; i++) {
out_num = vc7_map_index_to_output(vc7->chip_info->model, i);
/*
* This driver does not support remapping FOD/IOD to banks.
* The device state is read and the driver is setup to match
* the device's existing mapping.
*/
bank_idx = output_bank_mapping[out_num];
regmap_read(vc7->regmap, VC7_REG_OUT_BANK_CNFG(bank_idx), &val);
val &= VC7_REG_OUTPUT_BANK_SRC_MASK;
memset(&bank_src_map, 0, sizeof(bank_src_map));
ret = vc7_get_bank_clk(vc7, bank_idx, val, &bank_src_map);
if (ret) {
dev_err_probe(&client->dev, ret,
"unable to register output %d\n", i);
return ret;
}
switch (bank_src_map.type) {
case VC7_FOD:
parent_names[0] = clk_hw_get_name(&bank_src_map.src.fod->hw);
break;
case VC7_IOD:
parent_names[0] = clk_hw_get_name(&bank_src_map.src.iod->hw);
break;
}
memset(&clk_init, 0, sizeof(clk_init));
clk_init.name = kasprintf(GFP_KERNEL, "%s_out%d", node_name, i);
clk_init.ops = &vc7_clk_out_ops;
clk_init.flags = CLK_SET_RATE_PARENT;
clk_init.parent_names = parent_names;
clk_init.num_parents = 1;
vc7->clk_out[i].num = i;
vc7->clk_out[i].vc7 = vc7;
vc7->clk_out[i].hw.init = &clk_init;
ret = devm_clk_hw_register(&client->dev, &vc7->clk_out[i].hw);
if (ret)
goto err_clk_register;
kfree(clk_init.name); /* ccf made a copy of the name */
}
ret = of_clk_add_hw_provider(client->dev.of_node, vc7_of_clk_get, vc7);
if (ret) {
dev_err_probe(&client->dev, ret, "unable to add clk provider\n");
goto err_clk;
}
return ret;
err_clk_register:
dev_err_probe(&client->dev, ret,
"unable to register %s\n", clk_init.name);
kfree(clk_init.name); /* ccf made a copy of the name */
err_clk:
clk_unregister_fixed_rate(vc7->clk_apll.clk);
return ret;
}
static void vc7_remove(struct i2c_client *client)
{
struct vc7_driver_data *vc7 = i2c_get_clientdata(client);
of_clk_del_provider(client->dev.of_node);
clk_unregister_fixed_rate(vc7->clk_apll.clk);
}
static bool vc7_volatile_reg(struct device *dev, unsigned int reg)
{
if (reg == VC7_PAGE_ADDR)
return false;
return true;
}
static const struct vc7_chip_info vc7_rc21008a_info = {
.model = VC7_RC21008A,
.num_banks = 6,
.num_outputs = 8,
};
static struct regmap_range_cfg vc7_range_cfg[] = {
{
.range_min = 0,
.range_max = VC7_MAX_REG,
.selector_reg = VC7_PAGE_ADDR,
.selector_mask = 0xFF,
.selector_shift = 0,
.window_start = 0,
.window_len = VC7_PAGE_WINDOW,
}};
static const struct regmap_config vc7_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = VC7_MAX_REG,
.ranges = vc7_range_cfg,
.num_ranges = ARRAY_SIZE(vc7_range_cfg),
.volatile_reg = vc7_volatile_reg,
.cache_type = REGCACHE_RBTREE,
.can_multi_write = true,
.reg_format_endian = REGMAP_ENDIAN_LITTLE,
.val_format_endian = REGMAP_ENDIAN_LITTLE,
};
static const struct i2c_device_id vc7_i2c_id[] = {
{ "rc21008a", VC7_RC21008A },
{}
};
MODULE_DEVICE_TABLE(i2c, vc7_i2c_id);
static const struct of_device_id vc7_of_match[] = {
{ .compatible = "renesas,rc21008a", .data = &vc7_rc21008a_info },
{}
};
MODULE_DEVICE_TABLE(of, vc7_of_match);
static struct i2c_driver vc7_i2c_driver = {
.driver = {
.name = "vc7",
.of_match_table = vc7_of_match,
},
.probe_new = vc7_probe,
.remove = vc7_remove,
.id_table = vc7_i2c_id,
};
module_i2c_driver(vc7_i2c_driver);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alex Helms <alexander.helms.jy@renesas.com");
MODULE_DESCRIPTION("Renesas Versaclock7 common clock framework driver");
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