xref: /openbmc/linux/drivers/clk/qcom/clk-spmi-pmic-div.c (revision c900529f3d9161bfde5cca0754f83b4d3c3e0220)
197fb5e8dSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
24cfaa55fSTirupathi Reddy /* Copyright (c) 2017, The Linux Foundation. All rights reserved.
34cfaa55fSTirupathi Reddy  */
44cfaa55fSTirupathi Reddy 
54cfaa55fSTirupathi Reddy #include <linux/bitops.h>
64cfaa55fSTirupathi Reddy #include <linux/clk.h>
74cfaa55fSTirupathi Reddy #include <linux/clk-provider.h>
84cfaa55fSTirupathi Reddy #include <linux/delay.h>
94cfaa55fSTirupathi Reddy #include <linux/err.h>
104cfaa55fSTirupathi Reddy #include <linux/log2.h>
114cfaa55fSTirupathi Reddy #include <linux/module.h>
124cfaa55fSTirupathi Reddy #include <linux/of.h>
134cfaa55fSTirupathi Reddy #include <linux/platform_device.h>
144cfaa55fSTirupathi Reddy #include <linux/regmap.h>
154cfaa55fSTirupathi Reddy #include <linux/slab.h>
164cfaa55fSTirupathi Reddy #include <linux/types.h>
174cfaa55fSTirupathi Reddy 
184cfaa55fSTirupathi Reddy #define REG_DIV_CTL1			0x43
194cfaa55fSTirupathi Reddy #define DIV_CTL1_DIV_FACTOR_MASK	GENMASK(2, 0)
204cfaa55fSTirupathi Reddy 
214cfaa55fSTirupathi Reddy #define REG_EN_CTL			0x46
224cfaa55fSTirupathi Reddy #define REG_EN_MASK			BIT(7)
234cfaa55fSTirupathi Reddy 
244cfaa55fSTirupathi Reddy struct clkdiv {
254cfaa55fSTirupathi Reddy 	struct regmap		*regmap;
264cfaa55fSTirupathi Reddy 	u16			base;
274cfaa55fSTirupathi Reddy 	spinlock_t		lock;
284cfaa55fSTirupathi Reddy 
294cfaa55fSTirupathi Reddy 	struct clk_hw		hw;
304cfaa55fSTirupathi Reddy 	unsigned int		cxo_period_ns;
314cfaa55fSTirupathi Reddy };
324cfaa55fSTirupathi Reddy 
to_clkdiv(struct clk_hw * hw)334cfaa55fSTirupathi Reddy static inline struct clkdiv *to_clkdiv(struct clk_hw *hw)
344cfaa55fSTirupathi Reddy {
354cfaa55fSTirupathi Reddy 	return container_of(hw, struct clkdiv, hw);
364cfaa55fSTirupathi Reddy }
374cfaa55fSTirupathi Reddy 
div_factor_to_div(unsigned int div_factor)384cfaa55fSTirupathi Reddy static inline unsigned int div_factor_to_div(unsigned int div_factor)
394cfaa55fSTirupathi Reddy {
404cfaa55fSTirupathi Reddy 	if (!div_factor)
414cfaa55fSTirupathi Reddy 		div_factor = 1;
424cfaa55fSTirupathi Reddy 
434cfaa55fSTirupathi Reddy 	return 1 << (div_factor - 1);
444cfaa55fSTirupathi Reddy }
454cfaa55fSTirupathi Reddy 
div_to_div_factor(unsigned int div)464cfaa55fSTirupathi Reddy static inline unsigned int div_to_div_factor(unsigned int div)
474cfaa55fSTirupathi Reddy {
484cfaa55fSTirupathi Reddy 	return min(ilog2(div) + 1, 7);
494cfaa55fSTirupathi Reddy }
504cfaa55fSTirupathi Reddy 
is_spmi_pmic_clkdiv_enabled(struct clkdiv * clkdiv)514cfaa55fSTirupathi Reddy static bool is_spmi_pmic_clkdiv_enabled(struct clkdiv *clkdiv)
524cfaa55fSTirupathi Reddy {
534cfaa55fSTirupathi Reddy 	unsigned int val = 0;
544cfaa55fSTirupathi Reddy 
554cfaa55fSTirupathi Reddy 	regmap_read(clkdiv->regmap, clkdiv->base + REG_EN_CTL, &val);
564cfaa55fSTirupathi Reddy 
574cfaa55fSTirupathi Reddy 	return val & REG_EN_MASK;
584cfaa55fSTirupathi Reddy }
594cfaa55fSTirupathi Reddy 
604cfaa55fSTirupathi Reddy static int
__spmi_pmic_clkdiv_set_enable_state(struct clkdiv * clkdiv,bool enable,unsigned int div_factor)614cfaa55fSTirupathi Reddy __spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable,
624cfaa55fSTirupathi Reddy 				    unsigned int div_factor)
634cfaa55fSTirupathi Reddy {
644cfaa55fSTirupathi Reddy 	int ret;
654cfaa55fSTirupathi Reddy 	unsigned int ns = clkdiv->cxo_period_ns;
664cfaa55fSTirupathi Reddy 	unsigned int div = div_factor_to_div(div_factor);
674cfaa55fSTirupathi Reddy 
684cfaa55fSTirupathi Reddy 	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_EN_CTL,
694cfaa55fSTirupathi Reddy 				 REG_EN_MASK, enable ? REG_EN_MASK : 0);
704cfaa55fSTirupathi Reddy 	if (ret)
714cfaa55fSTirupathi Reddy 		return ret;
724cfaa55fSTirupathi Reddy 
734cfaa55fSTirupathi Reddy 	if (enable)
744cfaa55fSTirupathi Reddy 		ndelay((2 + 3 * div) * ns);
754cfaa55fSTirupathi Reddy 	else
764cfaa55fSTirupathi Reddy 		ndelay(3 * div * ns);
774cfaa55fSTirupathi Reddy 
784cfaa55fSTirupathi Reddy 	return 0;
794cfaa55fSTirupathi Reddy }
804cfaa55fSTirupathi Reddy 
spmi_pmic_clkdiv_set_enable_state(struct clkdiv * clkdiv,bool enable)814cfaa55fSTirupathi Reddy static int spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable)
824cfaa55fSTirupathi Reddy {
834cfaa55fSTirupathi Reddy 	unsigned int div_factor;
844cfaa55fSTirupathi Reddy 
854cfaa55fSTirupathi Reddy 	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);
864cfaa55fSTirupathi Reddy 	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;
874cfaa55fSTirupathi Reddy 
884cfaa55fSTirupathi Reddy 	return __spmi_pmic_clkdiv_set_enable_state(clkdiv, enable, div_factor);
894cfaa55fSTirupathi Reddy }
904cfaa55fSTirupathi Reddy 
clk_spmi_pmic_div_enable(struct clk_hw * hw)914cfaa55fSTirupathi Reddy static int clk_spmi_pmic_div_enable(struct clk_hw *hw)
924cfaa55fSTirupathi Reddy {
934cfaa55fSTirupathi Reddy 	struct clkdiv *clkdiv = to_clkdiv(hw);
944cfaa55fSTirupathi Reddy 	unsigned long flags;
954cfaa55fSTirupathi Reddy 	int ret;
964cfaa55fSTirupathi Reddy 
974cfaa55fSTirupathi Reddy 	spin_lock_irqsave(&clkdiv->lock, flags);
984cfaa55fSTirupathi Reddy 	ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, true);
994cfaa55fSTirupathi Reddy 	spin_unlock_irqrestore(&clkdiv->lock, flags);
1004cfaa55fSTirupathi Reddy 
1014cfaa55fSTirupathi Reddy 	return ret;
1024cfaa55fSTirupathi Reddy }
1034cfaa55fSTirupathi Reddy 
clk_spmi_pmic_div_disable(struct clk_hw * hw)1044cfaa55fSTirupathi Reddy static void clk_spmi_pmic_div_disable(struct clk_hw *hw)
1054cfaa55fSTirupathi Reddy {
1064cfaa55fSTirupathi Reddy 	struct clkdiv *clkdiv = to_clkdiv(hw);
1074cfaa55fSTirupathi Reddy 	unsigned long flags;
1084cfaa55fSTirupathi Reddy 
1094cfaa55fSTirupathi Reddy 	spin_lock_irqsave(&clkdiv->lock, flags);
1104cfaa55fSTirupathi Reddy 	spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
1114cfaa55fSTirupathi Reddy 	spin_unlock_irqrestore(&clkdiv->lock, flags);
1124cfaa55fSTirupathi Reddy }
1134cfaa55fSTirupathi Reddy 
clk_spmi_pmic_div_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * parent_rate)1144cfaa55fSTirupathi Reddy static long clk_spmi_pmic_div_round_rate(struct clk_hw *hw, unsigned long rate,
1154cfaa55fSTirupathi Reddy 					 unsigned long *parent_rate)
1164cfaa55fSTirupathi Reddy {
1174cfaa55fSTirupathi Reddy 	unsigned int div, div_factor;
1184cfaa55fSTirupathi Reddy 
1194cfaa55fSTirupathi Reddy 	div = DIV_ROUND_UP(*parent_rate, rate);
1204cfaa55fSTirupathi Reddy 	div_factor = div_to_div_factor(div);
1214cfaa55fSTirupathi Reddy 	div = div_factor_to_div(div_factor);
1224cfaa55fSTirupathi Reddy 
1234cfaa55fSTirupathi Reddy 	return *parent_rate / div;
1244cfaa55fSTirupathi Reddy }
1254cfaa55fSTirupathi Reddy 
1264cfaa55fSTirupathi Reddy static unsigned long
clk_spmi_pmic_div_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)1274cfaa55fSTirupathi Reddy clk_spmi_pmic_div_recalc_rate(struct clk_hw *hw, unsigned long parent_rate)
1284cfaa55fSTirupathi Reddy {
1294cfaa55fSTirupathi Reddy 	struct clkdiv *clkdiv = to_clkdiv(hw);
1304cfaa55fSTirupathi Reddy 	unsigned int div_factor;
1314cfaa55fSTirupathi Reddy 
1324cfaa55fSTirupathi Reddy 	regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor);
1334cfaa55fSTirupathi Reddy 	div_factor &= DIV_CTL1_DIV_FACTOR_MASK;
1344cfaa55fSTirupathi Reddy 
1354cfaa55fSTirupathi Reddy 	return parent_rate / div_factor_to_div(div_factor);
1364cfaa55fSTirupathi Reddy }
1374cfaa55fSTirupathi Reddy 
clk_spmi_pmic_div_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)1384cfaa55fSTirupathi Reddy static int clk_spmi_pmic_div_set_rate(struct clk_hw *hw, unsigned long rate,
1394cfaa55fSTirupathi Reddy 				      unsigned long parent_rate)
1404cfaa55fSTirupathi Reddy {
1414cfaa55fSTirupathi Reddy 	struct clkdiv *clkdiv = to_clkdiv(hw);
1424cfaa55fSTirupathi Reddy 	unsigned int div_factor = div_to_div_factor(parent_rate / rate);
1434cfaa55fSTirupathi Reddy 	unsigned long flags;
1444cfaa55fSTirupathi Reddy 	bool enabled;
1454cfaa55fSTirupathi Reddy 	int ret;
1464cfaa55fSTirupathi Reddy 
1474cfaa55fSTirupathi Reddy 	spin_lock_irqsave(&clkdiv->lock, flags);
1484cfaa55fSTirupathi Reddy 	enabled = is_spmi_pmic_clkdiv_enabled(clkdiv);
1494cfaa55fSTirupathi Reddy 	if (enabled) {
1504cfaa55fSTirupathi Reddy 		ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
1514cfaa55fSTirupathi Reddy 		if (ret)
1524cfaa55fSTirupathi Reddy 			goto unlock;
1534cfaa55fSTirupathi Reddy 	}
1544cfaa55fSTirupathi Reddy 
1554cfaa55fSTirupathi Reddy 	ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1,
1564cfaa55fSTirupathi Reddy 				 DIV_CTL1_DIV_FACTOR_MASK, div_factor);
1574cfaa55fSTirupathi Reddy 	if (ret)
1584cfaa55fSTirupathi Reddy 		goto unlock;
1594cfaa55fSTirupathi Reddy 
1604cfaa55fSTirupathi Reddy 	if (enabled)
1614cfaa55fSTirupathi Reddy 		ret = __spmi_pmic_clkdiv_set_enable_state(clkdiv, true,
1624cfaa55fSTirupathi Reddy 							  div_factor);
1634cfaa55fSTirupathi Reddy 
1644cfaa55fSTirupathi Reddy unlock:
1654cfaa55fSTirupathi Reddy 	spin_unlock_irqrestore(&clkdiv->lock, flags);
1664cfaa55fSTirupathi Reddy 
1674cfaa55fSTirupathi Reddy 	return ret;
1684cfaa55fSTirupathi Reddy }
1694cfaa55fSTirupathi Reddy 
1704cfaa55fSTirupathi Reddy static const struct clk_ops clk_spmi_pmic_div_ops = {
1714cfaa55fSTirupathi Reddy 	.enable = clk_spmi_pmic_div_enable,
1724cfaa55fSTirupathi Reddy 	.disable = clk_spmi_pmic_div_disable,
1734cfaa55fSTirupathi Reddy 	.set_rate = clk_spmi_pmic_div_set_rate,
1744cfaa55fSTirupathi Reddy 	.recalc_rate = clk_spmi_pmic_div_recalc_rate,
1754cfaa55fSTirupathi Reddy 	.round_rate = clk_spmi_pmic_div_round_rate,
1764cfaa55fSTirupathi Reddy };
1774cfaa55fSTirupathi Reddy 
1784cfaa55fSTirupathi Reddy struct spmi_pmic_div_clk_cc {
1794cfaa55fSTirupathi Reddy 	int		nclks;
180*a5be6db5SKees Cook 	struct clkdiv	clks[] __counted_by(nclks);
1814cfaa55fSTirupathi Reddy };
1824cfaa55fSTirupathi Reddy 
1834cfaa55fSTirupathi Reddy static struct clk_hw *
spmi_pmic_div_clk_hw_get(struct of_phandle_args * clkspec,void * data)1844cfaa55fSTirupathi Reddy spmi_pmic_div_clk_hw_get(struct of_phandle_args *clkspec, void *data)
1854cfaa55fSTirupathi Reddy {
1864cfaa55fSTirupathi Reddy 	struct spmi_pmic_div_clk_cc *cc = data;
1874cfaa55fSTirupathi Reddy 	int idx = clkspec->args[0] - 1; /* Start at 1 instead of 0 */
1884cfaa55fSTirupathi Reddy 
1894cfaa55fSTirupathi Reddy 	if (idx < 0 || idx >= cc->nclks) {
1904cfaa55fSTirupathi Reddy 		pr_err("%s: index value %u is invalid; allowed range [1, %d]\n",
1914cfaa55fSTirupathi Reddy 		       __func__, clkspec->args[0], cc->nclks);
1924cfaa55fSTirupathi Reddy 		return ERR_PTR(-EINVAL);
1934cfaa55fSTirupathi Reddy 	}
1944cfaa55fSTirupathi Reddy 
1954cfaa55fSTirupathi Reddy 	return &cc->clks[idx].hw;
1964cfaa55fSTirupathi Reddy }
1974cfaa55fSTirupathi Reddy 
spmi_pmic_clkdiv_probe(struct platform_device * pdev)1984cfaa55fSTirupathi Reddy static int spmi_pmic_clkdiv_probe(struct platform_device *pdev)
1994cfaa55fSTirupathi Reddy {
2004cfaa55fSTirupathi Reddy 	struct spmi_pmic_div_clk_cc *cc;
2014cfaa55fSTirupathi Reddy 	struct clk_init_data init = {};
2024cfaa55fSTirupathi Reddy 	struct clkdiv *clkdiv;
2034cfaa55fSTirupathi Reddy 	struct clk *cxo;
2044cfaa55fSTirupathi Reddy 	struct regmap *regmap;
2054cfaa55fSTirupathi Reddy 	struct device *dev = &pdev->dev;
2064cfaa55fSTirupathi Reddy 	struct device_node *of_node = dev->of_node;
207a622c1dcSDmitry Baryshkov 	struct clk_parent_data parent_data = { .index = 0, };
2084cfaa55fSTirupathi Reddy 	int nclks, i, ret, cxo_hz;
2094cfaa55fSTirupathi Reddy 	char name[20];
2104cfaa55fSTirupathi Reddy 	u32 start;
2114cfaa55fSTirupathi Reddy 
2124cfaa55fSTirupathi Reddy 	ret = of_property_read_u32(of_node, "reg", &start);
2134cfaa55fSTirupathi Reddy 	if (ret < 0) {
2144cfaa55fSTirupathi Reddy 		dev_err(dev, "reg property reading failed\n");
2154cfaa55fSTirupathi Reddy 		return ret;
2164cfaa55fSTirupathi Reddy 	}
2174cfaa55fSTirupathi Reddy 
2184cfaa55fSTirupathi Reddy 	regmap = dev_get_regmap(dev->parent, NULL);
2194cfaa55fSTirupathi Reddy 	if (!regmap) {
2204cfaa55fSTirupathi Reddy 		dev_err(dev, "Couldn't get parent's regmap\n");
2214cfaa55fSTirupathi Reddy 		return -EINVAL;
2224cfaa55fSTirupathi Reddy 	}
2234cfaa55fSTirupathi Reddy 
2244cfaa55fSTirupathi Reddy 	ret = of_property_read_u32(of_node, "qcom,num-clkdivs", &nclks);
2254cfaa55fSTirupathi Reddy 	if (ret < 0) {
2264cfaa55fSTirupathi Reddy 		dev_err(dev, "qcom,num-clkdivs property reading failed, ret=%d\n",
2274cfaa55fSTirupathi Reddy 			ret);
2284cfaa55fSTirupathi Reddy 		return ret;
2294cfaa55fSTirupathi Reddy 	}
2304cfaa55fSTirupathi Reddy 
2314cfaa55fSTirupathi Reddy 	if (!nclks)
2324cfaa55fSTirupathi Reddy 		return -EINVAL;
2334cfaa55fSTirupathi Reddy 
2340ed2dd03SKees Cook 	cc = devm_kzalloc(dev, struct_size(cc, clks, nclks), GFP_KERNEL);
2354cfaa55fSTirupathi Reddy 	if (!cc)
2364cfaa55fSTirupathi Reddy 		return -ENOMEM;
2374cfaa55fSTirupathi Reddy 	cc->nclks = nclks;
2384cfaa55fSTirupathi Reddy 
2394cfaa55fSTirupathi Reddy 	cxo = clk_get(dev, "xo");
2404cfaa55fSTirupathi Reddy 	if (IS_ERR(cxo)) {
2414cfaa55fSTirupathi Reddy 		ret = PTR_ERR(cxo);
2424cfaa55fSTirupathi Reddy 		if (ret != -EPROBE_DEFER)
2434cfaa55fSTirupathi Reddy 			dev_err(dev, "failed to get xo clock\n");
2444cfaa55fSTirupathi Reddy 		return ret;
2454cfaa55fSTirupathi Reddy 	}
2464cfaa55fSTirupathi Reddy 	cxo_hz = clk_get_rate(cxo);
2474cfaa55fSTirupathi Reddy 	clk_put(cxo);
2484cfaa55fSTirupathi Reddy 
2494cfaa55fSTirupathi Reddy 	init.name = name;
250a622c1dcSDmitry Baryshkov 	init.parent_data = &parent_data;
2514cfaa55fSTirupathi Reddy 	init.num_parents = 1;
2524cfaa55fSTirupathi Reddy 	init.ops = &clk_spmi_pmic_div_ops;
2534cfaa55fSTirupathi Reddy 
2544cfaa55fSTirupathi Reddy 	for (i = 0, clkdiv = cc->clks; i < nclks; i++) {
2554cfaa55fSTirupathi Reddy 		snprintf(name, sizeof(name), "div_clk%d", i + 1);
2564cfaa55fSTirupathi Reddy 
2574cfaa55fSTirupathi Reddy 		spin_lock_init(&clkdiv[i].lock);
2584cfaa55fSTirupathi Reddy 		clkdiv[i].base = start + i * 0x100;
2594cfaa55fSTirupathi Reddy 		clkdiv[i].regmap = regmap;
2604cfaa55fSTirupathi Reddy 		clkdiv[i].cxo_period_ns = NSEC_PER_SEC / cxo_hz;
2614cfaa55fSTirupathi Reddy 		clkdiv[i].hw.init = &init;
2624cfaa55fSTirupathi Reddy 
2634cfaa55fSTirupathi Reddy 		ret = devm_clk_hw_register(dev, &clkdiv[i].hw);
2644cfaa55fSTirupathi Reddy 		if (ret)
2654cfaa55fSTirupathi Reddy 			return ret;
2664cfaa55fSTirupathi Reddy 	}
2674cfaa55fSTirupathi Reddy 
2684cfaa55fSTirupathi Reddy 	return devm_of_clk_add_hw_provider(dev, spmi_pmic_div_clk_hw_get, cc);
2694cfaa55fSTirupathi Reddy }
2704cfaa55fSTirupathi Reddy 
2714cfaa55fSTirupathi Reddy static const struct of_device_id spmi_pmic_clkdiv_match_table[] = {
2724cfaa55fSTirupathi Reddy 	{ .compatible = "qcom,spmi-clkdiv" },
2734cfaa55fSTirupathi Reddy 	{ /* sentinel */ }
2744cfaa55fSTirupathi Reddy };
2754cfaa55fSTirupathi Reddy MODULE_DEVICE_TABLE(of, spmi_pmic_clkdiv_match_table);
2764cfaa55fSTirupathi Reddy 
2774cfaa55fSTirupathi Reddy static struct platform_driver spmi_pmic_clkdiv_driver = {
2784cfaa55fSTirupathi Reddy 	.driver		= {
2794cfaa55fSTirupathi Reddy 		.name	= "qcom,spmi-pmic-clkdiv",
2804cfaa55fSTirupathi Reddy 		.of_match_table = spmi_pmic_clkdiv_match_table,
2814cfaa55fSTirupathi Reddy 	},
2824cfaa55fSTirupathi Reddy 	.probe		= spmi_pmic_clkdiv_probe,
2834cfaa55fSTirupathi Reddy };
2844cfaa55fSTirupathi Reddy module_platform_driver(spmi_pmic_clkdiv_driver);
2854cfaa55fSTirupathi Reddy 
2864cfaa55fSTirupathi Reddy MODULE_DESCRIPTION("QCOM SPMI PMIC clkdiv driver");
2874cfaa55fSTirupathi Reddy MODULE_LICENSE("GPL v2");
288