linux/drivers/clk/clk-vt8500.c
Thomas Gleixner 9c92ab6191 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 282
Based on 1 normalized pattern(s):

  this software is licensed under the terms of the gnu general public
  license version 2 as published by the free software foundation and
  may be copied distributed and modified under those terms 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 285 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00

745 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Clock implementation for VIA/Wondermedia SoC's
* Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
*/
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/bitops.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#define LEGACY_PMC_BASE 0xD8130000
/* All clocks share the same lock as none can be changed concurrently */
static DEFINE_SPINLOCK(_lock);
struct clk_device {
struct clk_hw hw;
void __iomem *div_reg;
unsigned int div_mask;
void __iomem *en_reg;
int en_bit;
spinlock_t *lock;
};
/*
* Add new PLL_TYPE_x definitions here as required. Use the first known model
* to support the new type as the name.
* Add case statements to vtwm_pll_recalc_rate(), vtwm_pll_round_round() and
* vtwm_pll_set_rate() to handle the new PLL_TYPE_x
*/
#define PLL_TYPE_VT8500 0
#define PLL_TYPE_WM8650 1
#define PLL_TYPE_WM8750 2
#define PLL_TYPE_WM8850 3
struct clk_pll {
struct clk_hw hw;
void __iomem *reg;
spinlock_t *lock;
int type;
};
static void __iomem *pmc_base;
static __init void vtwm_set_pmc_base(void)
{
struct device_node *np =
of_find_compatible_node(NULL, NULL, "via,vt8500-pmc");
if (np)
pmc_base = of_iomap(np, 0);
else
pmc_base = ioremap(LEGACY_PMC_BASE, 0x1000);
of_node_put(np);
if (!pmc_base)
pr_err("%s:of_iomap(pmc) failed\n", __func__);
}
#define to_clk_device(_hw) container_of(_hw, struct clk_device, hw)
#define VT8500_PMC_BUSY_MASK 0x18
static void vt8500_pmc_wait_busy(void)
{
while (readl(pmc_base) & VT8500_PMC_BUSY_MASK)
cpu_relax();
}
static int vt8500_dclk_enable(struct clk_hw *hw)
{
struct clk_device *cdev = to_clk_device(hw);
u32 en_val;
unsigned long flags = 0;
spin_lock_irqsave(cdev->lock, flags);
en_val = readl(cdev->en_reg);
en_val |= BIT(cdev->en_bit);
writel(en_val, cdev->en_reg);
spin_unlock_irqrestore(cdev->lock, flags);
return 0;
}
static void vt8500_dclk_disable(struct clk_hw *hw)
{
struct clk_device *cdev = to_clk_device(hw);
u32 en_val;
unsigned long flags = 0;
spin_lock_irqsave(cdev->lock, flags);
en_val = readl(cdev->en_reg);
en_val &= ~BIT(cdev->en_bit);
writel(en_val, cdev->en_reg);
spin_unlock_irqrestore(cdev->lock, flags);
}
static int vt8500_dclk_is_enabled(struct clk_hw *hw)
{
struct clk_device *cdev = to_clk_device(hw);
u32 en_val = (readl(cdev->en_reg) & BIT(cdev->en_bit));
return en_val ? 1 : 0;
}
static unsigned long vt8500_dclk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_device *cdev = to_clk_device(hw);
u32 div = readl(cdev->div_reg) & cdev->div_mask;
/* Special case for SDMMC devices */
if ((cdev->div_mask == 0x3F) && (div & BIT(5)))
div = 64 * (div & 0x1f);
/* div == 0 is actually the highest divisor */
if (div == 0)
div = (cdev->div_mask + 1);
return parent_rate / div;
}
static long vt8500_dclk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_device *cdev = to_clk_device(hw);
u32 divisor;
if (rate == 0)
return 0;
divisor = *prate / rate;
/* If prate / rate would be decimal, incr the divisor */
if (rate * divisor < *prate)
divisor++;
/*
* If this is a request for SDMMC we have to adjust the divisor
* when >31 to use the fixed predivisor
*/
if ((cdev->div_mask == 0x3F) && (divisor > 31)) {
divisor = 64 * ((divisor / 64) + 1);
}
return *prate / divisor;
}
static int vt8500_dclk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_device *cdev = to_clk_device(hw);
u32 divisor;
unsigned long flags = 0;
if (rate == 0)
return 0;
divisor = parent_rate / rate;
if (divisor == cdev->div_mask + 1)
divisor = 0;
/* SDMMC mask may need to be corrected before testing if its valid */
if ((cdev->div_mask == 0x3F) && (divisor > 31)) {
/*
* Bit 5 is a fixed /64 predivisor. If the requested divisor
* is >31 then correct for the fixed divisor being required.
*/
divisor = 0x20 + (divisor / 64);
}
if (divisor > cdev->div_mask) {
pr_err("%s: invalid divisor for clock\n", __func__);
return -EINVAL;
}
spin_lock_irqsave(cdev->lock, flags);
vt8500_pmc_wait_busy();
writel(divisor, cdev->div_reg);
vt8500_pmc_wait_busy();
spin_unlock_irqrestore(cdev->lock, flags);
return 0;
}
static const struct clk_ops vt8500_gated_clk_ops = {
.enable = vt8500_dclk_enable,
.disable = vt8500_dclk_disable,
.is_enabled = vt8500_dclk_is_enabled,
};
static const struct clk_ops vt8500_divisor_clk_ops = {
.round_rate = vt8500_dclk_round_rate,
.set_rate = vt8500_dclk_set_rate,
.recalc_rate = vt8500_dclk_recalc_rate,
};
static const struct clk_ops vt8500_gated_divisor_clk_ops = {
.enable = vt8500_dclk_enable,
.disable = vt8500_dclk_disable,
.is_enabled = vt8500_dclk_is_enabled,
.round_rate = vt8500_dclk_round_rate,
.set_rate = vt8500_dclk_set_rate,
.recalc_rate = vt8500_dclk_recalc_rate,
};
#define CLK_INIT_GATED BIT(0)
#define CLK_INIT_DIVISOR BIT(1)
#define CLK_INIT_GATED_DIVISOR (CLK_INIT_DIVISOR | CLK_INIT_GATED)
static __init void vtwm_device_clk_init(struct device_node *node)
{
u32 en_reg, div_reg;
struct clk_hw *hw;
struct clk_device *dev_clk;
const char *clk_name = node->name;
const char *parent_name;
struct clk_init_data init;
int rc;
int clk_init_flags = 0;
if (!pmc_base)
vtwm_set_pmc_base();
dev_clk = kzalloc(sizeof(*dev_clk), GFP_KERNEL);
if (WARN_ON(!dev_clk))
return;
dev_clk->lock = &_lock;
rc = of_property_read_u32(node, "enable-reg", &en_reg);
if (!rc) {
dev_clk->en_reg = pmc_base + en_reg;
rc = of_property_read_u32(node, "enable-bit", &dev_clk->en_bit);
if (rc) {
pr_err("%s: enable-bit property required for gated clock\n",
__func__);
return;
}
clk_init_flags |= CLK_INIT_GATED;
}
rc = of_property_read_u32(node, "divisor-reg", &div_reg);
if (!rc) {
dev_clk->div_reg = pmc_base + div_reg;
/*
* use 0x1f as the default mask since it covers
* almost all the clocks and reduces dts properties
*/
dev_clk->div_mask = 0x1f;
of_property_read_u32(node, "divisor-mask", &dev_clk->div_mask);
clk_init_flags |= CLK_INIT_DIVISOR;
}
of_property_read_string(node, "clock-output-names", &clk_name);
switch (clk_init_flags) {
case CLK_INIT_GATED:
init.ops = &vt8500_gated_clk_ops;
break;
case CLK_INIT_DIVISOR:
init.ops = &vt8500_divisor_clk_ops;
break;
case CLK_INIT_GATED_DIVISOR:
init.ops = &vt8500_gated_divisor_clk_ops;
break;
default:
pr_err("%s: Invalid clock description in device tree\n",
__func__);
kfree(dev_clk);
return;
}
init.name = clk_name;
init.flags = 0;
parent_name = of_clk_get_parent_name(node, 0);
init.parent_names = &parent_name;
init.num_parents = 1;
dev_clk->hw.init = &init;
hw = &dev_clk->hw;
rc = clk_hw_register(NULL, hw);
if (WARN_ON(rc)) {
kfree(dev_clk);
return;
}
rc = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
clk_hw_register_clkdev(hw, clk_name, NULL);
}
CLK_OF_DECLARE(vt8500_device, "via,vt8500-device-clock", vtwm_device_clk_init);
/* PLL clock related functions */
#define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
/* Helper macros for PLL_VT8500 */
#define VT8500_PLL_MUL(x) ((x & 0x1F) << 1)
#define VT8500_PLL_DIV(x) ((x & 0x100) ? 1 : 2)
#define VT8500_BITS_TO_FREQ(r, m, d) \
((r / d) * m)
#define VT8500_BITS_TO_VAL(m, d) \
((d == 2 ? 0 : 0x100) | ((m >> 1) & 0x1F))
/* Helper macros for PLL_WM8650 */
#define WM8650_PLL_MUL(x) (x & 0x3FF)
#define WM8650_PLL_DIV(x) (((x >> 10) & 7) * (1 << ((x >> 13) & 3)))
#define WM8650_BITS_TO_FREQ(r, m, d1, d2) \
(r * m / (d1 * (1 << d2)))
#define WM8650_BITS_TO_VAL(m, d1, d2) \
((d2 << 13) | (d1 << 10) | (m & 0x3FF))
/* Helper macros for PLL_WM8750 */
#define WM8750_PLL_MUL(x) (((x >> 16) & 0xFF) + 1)
#define WM8750_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 7)))
#define WM8750_BITS_TO_FREQ(r, m, d1, d2) \
(r * (m+1) / ((d1+1) * (1 << d2)))
#define WM8750_BITS_TO_VAL(f, m, d1, d2) \
((f << 24) | ((m - 1) << 16) | ((d1 - 1) << 8) | d2)
/* Helper macros for PLL_WM8850 */
#define WM8850_PLL_MUL(x) ((((x >> 16) & 0x7F) + 1) * 2)
#define WM8850_PLL_DIV(x) ((((x >> 8) & 1) + 1) * (1 << (x & 3)))
#define WM8850_BITS_TO_FREQ(r, m, d1, d2) \
(r * ((m + 1) * 2) / ((d1+1) * (1 << d2)))
#define WM8850_BITS_TO_VAL(m, d1, d2) \
((((m / 2) - 1) << 16) | ((d1 - 1) << 8) | d2)
static int vt8500_find_pll_bits(unsigned long rate, unsigned long parent_rate,
u32 *multiplier, u32 *prediv)
{
unsigned long tclk;
/* sanity check */
if ((rate < parent_rate * 4) || (rate > parent_rate * 62)) {
pr_err("%s: requested rate out of range\n", __func__);
*multiplier = 0;
*prediv = 1;
return -EINVAL;
}
if (rate <= parent_rate * 31)
/* use the prediv to double the resolution */
*prediv = 2;
else
*prediv = 1;
*multiplier = rate / (parent_rate / *prediv);
tclk = (parent_rate / *prediv) * *multiplier;
if (tclk != rate)
pr_warn("%s: requested rate %lu, found rate %lu\n", __func__,
rate, tclk);
return 0;
}
/*
* M * parent [O1] => / P [O2] => / D [O3]
* Where O1 is 900MHz...3GHz;
* O2 is 600MHz >= (M * parent) / P >= 300MHz;
* M is 36...120 [25MHz parent]; D is 1 or 2 or 4 or 8.
* Possible ranges (O3):
* D = 8: 37,5MHz...75MHz
* D = 4: 75MHz...150MHz
* D = 2: 150MHz...300MHz
* D = 1: 300MHz...600MHz
*/
static int wm8650_find_pll_bits(unsigned long rate,
unsigned long parent_rate, u32 *multiplier, u32 *divisor1,
u32 *divisor2)
{
unsigned long O1, min_err, rate_err;
if (!parent_rate || (rate < 37500000) || (rate > 600000000))
return -EINVAL;
*divisor2 = rate <= 75000000 ? 3 : rate <= 150000000 ? 2 :
rate <= 300000000 ? 1 : 0;
/*
* Divisor P cannot be calculated. Test all divisors and find where M
* will be as close as possible to the requested rate.
*/
min_err = ULONG_MAX;
for (*divisor1 = 5; *divisor1 >= 3; (*divisor1)--) {
O1 = rate * *divisor1 * (1 << (*divisor2));
rate_err = O1 % parent_rate;
if (rate_err < min_err) {
*multiplier = O1 / parent_rate;
if (rate_err == 0)
return 0;
min_err = rate_err;
}
}
if ((*multiplier < 3) || (*multiplier > 1023))
return -EINVAL;
pr_warn("%s: rate error is %lu\n", __func__, min_err);
return 0;
}
static u32 wm8750_get_filter(u32 parent_rate, u32 divisor1)
{
/* calculate frequency (MHz) after pre-divisor */
u32 freq = (parent_rate / 1000000) / (divisor1 + 1);
if ((freq < 10) || (freq > 200))
pr_warn("%s: PLL recommended input frequency 10..200Mhz (requested %d Mhz)\n",
__func__, freq);
if (freq >= 166)
return 7;
else if (freq >= 104)
return 6;
else if (freq >= 65)
return 5;
else if (freq >= 42)
return 4;
else if (freq >= 26)
return 3;
else if (freq >= 16)
return 2;
else if (freq >= 10)
return 1;
return 0;
}
static int wm8750_find_pll_bits(unsigned long rate, unsigned long parent_rate,
u32 *filter, u32 *multiplier, u32 *divisor1, u32 *divisor2)
{
u32 mul;
int div1, div2;
unsigned long tclk, rate_err, best_err;
best_err = (unsigned long)-1;
/* Find the closest match (lower or equal to requested) */
for (div1 = 1; div1 >= 0; div1--)
for (div2 = 7; div2 >= 0; div2--)
for (mul = 0; mul <= 255; mul++) {
tclk = parent_rate * (mul + 1) / ((div1 + 1) * (1 << div2));
if (tclk > rate)
continue;
/* error will always be +ve */
rate_err = rate - tclk;
if (rate_err == 0) {
*filter = wm8750_get_filter(parent_rate, div1);
*multiplier = mul;
*divisor1 = div1;
*divisor2 = div2;
return 0;
}
if (rate_err < best_err) {
best_err = rate_err;
*multiplier = mul;
*divisor1 = div1;
*divisor2 = div2;
}
}
if (best_err == (unsigned long)-1) {
pr_warn("%s: impossible rate %lu\n", __func__, rate);
return -EINVAL;
}
/* if we got here, it wasn't an exact match */
pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
rate - best_err);
*filter = wm8750_get_filter(parent_rate, *divisor1);
return 0;
}
static int wm8850_find_pll_bits(unsigned long rate, unsigned long parent_rate,
u32 *multiplier, u32 *divisor1, u32 *divisor2)
{
u32 mul;
int div1, div2;
unsigned long tclk, rate_err, best_err;
best_err = (unsigned long)-1;
/* Find the closest match (lower or equal to requested) */
for (div1 = 1; div1 >= 0; div1--)
for (div2 = 3; div2 >= 0; div2--)
for (mul = 0; mul <= 127; mul++) {
tclk = parent_rate * ((mul + 1) * 2) /
((div1 + 1) * (1 << div2));
if (tclk > rate)
continue;
/* error will always be +ve */
rate_err = rate - tclk;
if (rate_err == 0) {
*multiplier = mul;
*divisor1 = div1;
*divisor2 = div2;
return 0;
}
if (rate_err < best_err) {
best_err = rate_err;
*multiplier = mul;
*divisor1 = div1;
*divisor2 = div2;
}
}
if (best_err == (unsigned long)-1) {
pr_warn("%s: impossible rate %lu\n", __func__, rate);
return -EINVAL;
}
/* if we got here, it wasn't an exact match */
pr_warn("%s: requested rate %lu, found rate %lu\n", __func__, rate,
rate - best_err);
return 0;
}
static int vtwm_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_pll *pll = to_clk_pll(hw);
u32 filter, mul, div1, div2;
u32 pll_val;
unsigned long flags = 0;
int ret;
/* sanity check */
switch (pll->type) {
case PLL_TYPE_VT8500:
ret = vt8500_find_pll_bits(rate, parent_rate, &mul, &div1);
if (!ret)
pll_val = VT8500_BITS_TO_VAL(mul, div1);
break;
case PLL_TYPE_WM8650:
ret = wm8650_find_pll_bits(rate, parent_rate, &mul, &div1, &div2);
if (!ret)
pll_val = WM8650_BITS_TO_VAL(mul, div1, div2);
break;
case PLL_TYPE_WM8750:
ret = wm8750_find_pll_bits(rate, parent_rate, &filter, &mul, &div1, &div2);
if (!ret)
pll_val = WM8750_BITS_TO_VAL(filter, mul, div1, div2);
break;
case PLL_TYPE_WM8850:
ret = wm8850_find_pll_bits(rate, parent_rate, &mul, &div1, &div2);
if (!ret)
pll_val = WM8850_BITS_TO_VAL(mul, div1, div2);
break;
default:
pr_err("%s: invalid pll type\n", __func__);
ret = -EINVAL;
}
if (ret)
return ret;
spin_lock_irqsave(pll->lock, flags);
vt8500_pmc_wait_busy();
writel(pll_val, pll->reg);
vt8500_pmc_wait_busy();
spin_unlock_irqrestore(pll->lock, flags);
return 0;
}
static long vtwm_pll_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
struct clk_pll *pll = to_clk_pll(hw);
u32 filter, mul, div1, div2;
long round_rate;
int ret;
switch (pll->type) {
case PLL_TYPE_VT8500:
ret = vt8500_find_pll_bits(rate, *prate, &mul, &div1);
if (!ret)
round_rate = VT8500_BITS_TO_FREQ(*prate, mul, div1);
break;
case PLL_TYPE_WM8650:
ret = wm8650_find_pll_bits(rate, *prate, &mul, &div1, &div2);
if (!ret)
round_rate = WM8650_BITS_TO_FREQ(*prate, mul, div1, div2);
break;
case PLL_TYPE_WM8750:
ret = wm8750_find_pll_bits(rate, *prate, &filter, &mul, &div1, &div2);
if (!ret)
round_rate = WM8750_BITS_TO_FREQ(*prate, mul, div1, div2);
break;
case PLL_TYPE_WM8850:
ret = wm8850_find_pll_bits(rate, *prate, &mul, &div1, &div2);
if (!ret)
round_rate = WM8850_BITS_TO_FREQ(*prate, mul, div1, div2);
break;
default:
ret = -EINVAL;
}
if (ret)
return ret;
return round_rate;
}
static unsigned long vtwm_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_pll *pll = to_clk_pll(hw);
u32 pll_val = readl(pll->reg);
unsigned long pll_freq;
switch (pll->type) {
case PLL_TYPE_VT8500:
pll_freq = parent_rate * VT8500_PLL_MUL(pll_val);
pll_freq /= VT8500_PLL_DIV(pll_val);
break;
case PLL_TYPE_WM8650:
pll_freq = parent_rate * WM8650_PLL_MUL(pll_val);
pll_freq /= WM8650_PLL_DIV(pll_val);
break;
case PLL_TYPE_WM8750:
pll_freq = parent_rate * WM8750_PLL_MUL(pll_val);
pll_freq /= WM8750_PLL_DIV(pll_val);
break;
case PLL_TYPE_WM8850:
pll_freq = parent_rate * WM8850_PLL_MUL(pll_val);
pll_freq /= WM8850_PLL_DIV(pll_val);
break;
default:
pll_freq = 0;
}
return pll_freq;
}
static const struct clk_ops vtwm_pll_ops = {
.round_rate = vtwm_pll_round_rate,
.set_rate = vtwm_pll_set_rate,
.recalc_rate = vtwm_pll_recalc_rate,
};
static __init void vtwm_pll_clk_init(struct device_node *node, int pll_type)
{
u32 reg;
struct clk_hw *hw;
struct clk_pll *pll_clk;
const char *clk_name = node->name;
const char *parent_name;
struct clk_init_data init;
int rc;
if (!pmc_base)
vtwm_set_pmc_base();
rc = of_property_read_u32(node, "reg", &reg);
if (WARN_ON(rc))
return;
pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
if (WARN_ON(!pll_clk))
return;
pll_clk->reg = pmc_base + reg;
pll_clk->lock = &_lock;
pll_clk->type = pll_type;
of_property_read_string(node, "clock-output-names", &clk_name);
init.name = clk_name;
init.ops = &vtwm_pll_ops;
init.flags = 0;
parent_name = of_clk_get_parent_name(node, 0);
init.parent_names = &parent_name;
init.num_parents = 1;
pll_clk->hw.init = &init;
hw = &pll_clk->hw;
rc = clk_hw_register(NULL, &pll_clk->hw);
if (WARN_ON(rc)) {
kfree(pll_clk);
return;
}
rc = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw);
clk_hw_register_clkdev(hw, clk_name, NULL);
}
/* Wrappers for initialization functions */
static void __init vt8500_pll_init(struct device_node *node)
{
vtwm_pll_clk_init(node, PLL_TYPE_VT8500);
}
CLK_OF_DECLARE(vt8500_pll, "via,vt8500-pll-clock", vt8500_pll_init);
static void __init wm8650_pll_init(struct device_node *node)
{
vtwm_pll_clk_init(node, PLL_TYPE_WM8650);
}
CLK_OF_DECLARE(wm8650_pll, "wm,wm8650-pll-clock", wm8650_pll_init);
static void __init wm8750_pll_init(struct device_node *node)
{
vtwm_pll_clk_init(node, PLL_TYPE_WM8750);
}
CLK_OF_DECLARE(wm8750_pll, "wm,wm8750-pll-clock", wm8750_pll_init);
static void __init wm8850_pll_init(struct device_node *node)
{
vtwm_pll_clk_init(node, PLL_TYPE_WM8850);
}
CLK_OF_DECLARE(wm8850_pll, "wm,wm8850-pll-clock", wm8850_pll_init);