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linux/drivers/clk/clk-tps68470.c
Daniel Scally 43cf36974d platform/x86: int3472: Support multiple clock consumers 
At present, the tps68470.c only supports a single clock consumer when
passing platform data to the clock driver. In some devices multiple
sensors depend on the clock provided by a single TPS68470 and so all
need to be able to acquire the clock. Support passing multiple
consumers as platform data.

Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Daniel Scally <djrscally@gmail.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2022-09-24 19:12:32 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* Clock driver for TPS68470 PMIC
*
* Copyright (c) 2021 Red Hat Inc.
* Copyright (C) 2018 Intel Corporation
*
* Authors:
* Hans de Goede <hdegoede@redhat.com>
* Zaikuo Wang <zaikuo.wang@intel.com>
* Tianshu Qiu <tian.shu.qiu@intel.com>
* Jian Xu Zheng <jian.xu.zheng@intel.com>
* Yuning Pu <yuning.pu@intel.com>
* Antti Laakso <antti.laakso@intel.com>
*/
#include <linux/clk-provider.h>
#include <linux/clkdev.h>
#include <linux/kernel.h>
#include <linux/mfd/tps68470.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/platform_data/tps68470.h>
#include <linux/regmap.h>
#define TPS68470_CLK_NAME "tps68470-clk"
#define to_tps68470_clkdata(clkd) \
container_of(clkd, struct tps68470_clkdata, clkout_hw)
static struct tps68470_clkout_freqs {
unsigned long freq;
unsigned int xtaldiv;
unsigned int plldiv;
unsigned int postdiv;
unsigned int buckdiv;
unsigned int boostdiv;
} clk_freqs[] = {
/*
* The PLL is used to multiply the crystal oscillator
* frequency range of 3 MHz to 27 MHz by a programmable
* factor of F = (M/N)*(1/P) such that the output
* available at the HCLK_A or HCLK_B pins are in the range
* of 4 MHz to 64 MHz in increments of 0.1 MHz.
*
* hclk_# = osc_in * (((plldiv*2)+320) / (xtaldiv+30)) * (1 / 2^postdiv)
*
* PLL_REF_CLK should be as close as possible to 100kHz
* PLL_REF_CLK = input clk / XTALDIV[7:0] + 30)
*
* PLL_VCO_CLK = (PLL_REF_CLK * (plldiv*2 + 320))
*
* BOOST should be as close as possible to 2Mhz
* BOOST = PLL_VCO_CLK / (BOOSTDIV[4:0] + 16) *
*
* BUCK should be as close as possible to 5.2Mhz
* BUCK = PLL_VCO_CLK / (BUCKDIV[3:0] + 5)
*
* osc_in xtaldiv plldiv postdiv hclk_#
* 20Mhz 170 32 1 19.2Mhz
* 20Mhz 170 40 1 20Mhz
* 20Mhz 170 80 1 24Mhz
*/
{ 19200000, 170, 32, 1, 2, 3 },
{ 20000000, 170, 40, 1, 3, 4 },
{ 24000000, 170, 80, 1, 4, 8 },
};
struct tps68470_clkdata {
struct clk_hw clkout_hw;
struct regmap *regmap;
unsigned long rate;
};
static int tps68470_clk_is_prepared(struct clk_hw *hw)
{
struct tps68470_clkdata *clkdata = to_tps68470_clkdata(hw);
int val;
if (regmap_read(clkdata->regmap, TPS68470_REG_PLLCTL, &val))
return 0;
return val & TPS68470_PLL_EN_MASK;
}
static int tps68470_clk_prepare(struct clk_hw *hw)
{
struct tps68470_clkdata *clkdata = to_tps68470_clkdata(hw);
regmap_write(clkdata->regmap, TPS68470_REG_CLKCFG1,
(TPS68470_PLL_OUTPUT_ENABLE << TPS68470_OUTPUT_A_SHIFT) |
(TPS68470_PLL_OUTPUT_ENABLE << TPS68470_OUTPUT_B_SHIFT));
regmap_update_bits(clkdata->regmap, TPS68470_REG_PLLCTL,
TPS68470_PLL_EN_MASK, TPS68470_PLL_EN_MASK);
/*
* The PLLCTL reg lock bit is set by the PMIC after approx. 4ms and
* does not indicate a true lock, so just wait 4 ms.
*/
usleep_range(4000, 5000);
return 0;
}
static void tps68470_clk_unprepare(struct clk_hw *hw)
{
struct tps68470_clkdata *clkdata = to_tps68470_clkdata(hw);
/* Disable clock first ... */
regmap_update_bits(clkdata->regmap, TPS68470_REG_PLLCTL, TPS68470_PLL_EN_MASK, 0);
/* ... and then tri-state the clock outputs. */
regmap_write(clkdata->regmap, TPS68470_REG_CLKCFG1, 0);
}
static unsigned long tps68470_clk_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
{
struct tps68470_clkdata *clkdata = to_tps68470_clkdata(hw);
return clkdata->rate;
}
/*
* This returns the index of the clk_freqs[] cfg with the closest rate for
* use in tps68470_clk_round_rate(). tps68470_clk_set_rate() checks that
* the rate of the returned cfg is an exact match.
*/
static unsigned int tps68470_clk_cfg_lookup(unsigned long rate)
{
long diff, best_diff = LONG_MAX;
unsigned int i, best_idx = 0;
for (i = 0; i < ARRAY_SIZE(clk_freqs); i++) {
diff = clk_freqs[i].freq - rate;
if (diff == 0)
return i;
diff = abs(diff);
if (diff < best_diff) {
best_diff = diff;
best_idx = i;
}
}
return best_idx;
}
static long tps68470_clk_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
unsigned int idx = tps68470_clk_cfg_lookup(rate);
return clk_freqs[idx].freq;
}
static int tps68470_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct tps68470_clkdata *clkdata = to_tps68470_clkdata(hw);
unsigned int idx = tps68470_clk_cfg_lookup(rate);
if (rate != clk_freqs[idx].freq)
return -EINVAL;
regmap_write(clkdata->regmap, TPS68470_REG_BOOSTDIV, clk_freqs[idx].boostdiv);
regmap_write(clkdata->regmap, TPS68470_REG_BUCKDIV, clk_freqs[idx].buckdiv);
regmap_write(clkdata->regmap, TPS68470_REG_PLLSWR, TPS68470_PLLSWR_DEFAULT);
regmap_write(clkdata->regmap, TPS68470_REG_XTALDIV, clk_freqs[idx].xtaldiv);
regmap_write(clkdata->regmap, TPS68470_REG_PLLDIV, clk_freqs[idx].plldiv);
regmap_write(clkdata->regmap, TPS68470_REG_POSTDIV, clk_freqs[idx].postdiv);
regmap_write(clkdata->regmap, TPS68470_REG_POSTDIV2, clk_freqs[idx].postdiv);
regmap_write(clkdata->regmap, TPS68470_REG_CLKCFG2, TPS68470_CLKCFG2_DRV_STR_2MA);
regmap_write(clkdata->regmap, TPS68470_REG_PLLCTL,
TPS68470_OSC_EXT_CAP_DEFAULT << TPS68470_OSC_EXT_CAP_SHIFT |
TPS68470_CLK_SRC_XTAL << TPS68470_CLK_SRC_SHIFT);
clkdata->rate = rate;
return 0;
}
static const struct clk_ops tps68470_clk_ops = {
.is_prepared = tps68470_clk_is_prepared,
.prepare = tps68470_clk_prepare,
.unprepare = tps68470_clk_unprepare,
.recalc_rate = tps68470_clk_recalc_rate,
.round_rate = tps68470_clk_round_rate,
.set_rate = tps68470_clk_set_rate,
};
static int tps68470_clk_probe(struct platform_device *pdev)
{
struct tps68470_clk_platform_data *pdata = pdev->dev.platform_data;
struct clk_init_data tps68470_clk_initdata = {
.name = TPS68470_CLK_NAME,
.ops = &tps68470_clk_ops,
/* Changing the dividers when the PLL is on is not allowed */
.flags = CLK_SET_RATE_GATE,
};
struct tps68470_clkdata *tps68470_clkdata;
struct tps68470_clk_consumer *consumer;
int ret;
int i;
tps68470_clkdata = devm_kzalloc(&pdev->dev, sizeof(*tps68470_clkdata),
GFP_KERNEL);
if (!tps68470_clkdata)
return -ENOMEM;
tps68470_clkdata->regmap = dev_get_drvdata(pdev->dev.parent);
tps68470_clkdata->clkout_hw.init = &tps68470_clk_initdata;
/* Set initial rate */
tps68470_clk_set_rate(&tps68470_clkdata->clkout_hw, clk_freqs[0].freq, 0);
ret = devm_clk_hw_register(&pdev->dev, &tps68470_clkdata->clkout_hw);
if (ret)
return ret;
ret = devm_clk_hw_register_clkdev(&pdev->dev, &tps68470_clkdata->clkout_hw,
TPS68470_CLK_NAME, NULL);
if (ret)
return ret;
if (pdata) {
for (i = 0; i < pdata->n_consumers; i++) {
consumer = &pdata->consumers[i];
ret = devm_clk_hw_register_clkdev(&pdev->dev,
&tps68470_clkdata->clkout_hw,
consumer->consumer_con_id,
consumer->consumer_dev_name);
}
}
return ret;
}
static struct platform_driver tps68470_clk_driver = {
.driver = {
.name = TPS68470_CLK_NAME,
},
.probe = tps68470_clk_probe,
};
/*
* The ACPI tps68470 probe-ordering depends on the clk/gpio/regulator drivers
* registering before the drivers for the camera-sensors which use them bind.
* subsys_initcall() ensures this when the drivers are builtin.
*/
static int __init tps68470_clk_init(void)
{
return platform_driver_register(&tps68470_clk_driver);
}
subsys_initcall(tps68470_clk_init);
static void __exit tps68470_clk_exit(void)
{
platform_driver_unregister(&tps68470_clk_driver);
}
module_exit(tps68470_clk_exit);
MODULE_ALIAS("platform:tps68470-clk");
MODULE_DESCRIPTION("clock driver for TPS68470 pmic");
MODULE_LICENSE("GPL");
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