diff options
Diffstat (limited to 'drivers/clk/clk-tps68470.c')
| -rw-r--r-- | drivers/clk/clk-tps68470.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/clk/clk-tps68470.c b/drivers/clk/clk-tps68470.c new file mode 100644 index 000000000..38f44b5b9 --- /dev/null +++ b/drivers/clk/clk-tps68470.c @@ -0,0 +1,266 @@ +// 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"); |