diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/qcom/clk-spmi-pmic-div.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-spmi-pmic-div.c b/drivers/clk/qcom/clk-spmi-pmic-div.c new file mode 100644 index 0000000000..f394031eb0 --- /dev/null +++ b/drivers/clk/qcom/clk-spmi-pmic-div.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Copyright (c) 2017, The Linux Foundation. All rights reserved. + */ + +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/log2.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/types.h> + +#define REG_DIV_CTL1 0x43 +#define DIV_CTL1_DIV_FACTOR_MASK GENMASK(2, 0) + +#define REG_EN_CTL 0x46 +#define REG_EN_MASK BIT(7) + +struct clkdiv { + struct regmap *regmap; + u16 base; + spinlock_t lock; + + struct clk_hw hw; + unsigned int cxo_period_ns; +}; + +static inline struct clkdiv *to_clkdiv(struct clk_hw *hw) +{ + return container_of(hw, struct clkdiv, hw); +} + +static inline unsigned int div_factor_to_div(unsigned int div_factor) +{ + if (!div_factor) + div_factor = 1; + + return 1 << (div_factor - 1); +} + +static inline unsigned int div_to_div_factor(unsigned int div) +{ + return min(ilog2(div) + 1, 7); +} + +static bool is_spmi_pmic_clkdiv_enabled(struct clkdiv *clkdiv) +{ + unsigned int val = 0; + + regmap_read(clkdiv->regmap, clkdiv->base + REG_EN_CTL, &val); + + return val & REG_EN_MASK; +} + +static int +__spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable, + unsigned int div_factor) +{ + int ret; + unsigned int ns = clkdiv->cxo_period_ns; + unsigned int div = div_factor_to_div(div_factor); + + ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_EN_CTL, + REG_EN_MASK, enable ? REG_EN_MASK : 0); + if (ret) + return ret; + + if (enable) + ndelay((2 + 3 * div) * ns); + else + ndelay(3 * div * ns); + + return 0; +} + +static int spmi_pmic_clkdiv_set_enable_state(struct clkdiv *clkdiv, bool enable) +{ + unsigned int div_factor; + + regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor); + div_factor &= DIV_CTL1_DIV_FACTOR_MASK; + + return __spmi_pmic_clkdiv_set_enable_state(clkdiv, enable, div_factor); +} + +static int clk_spmi_pmic_div_enable(struct clk_hw *hw) +{ + struct clkdiv *clkdiv = to_clkdiv(hw); + unsigned long flags; + int ret; + + spin_lock_irqsave(&clkdiv->lock, flags); + ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, true); + spin_unlock_irqrestore(&clkdiv->lock, flags); + + return ret; +} + +static void clk_spmi_pmic_div_disable(struct clk_hw *hw) +{ + struct clkdiv *clkdiv = to_clkdiv(hw); + unsigned long flags; + + spin_lock_irqsave(&clkdiv->lock, flags); + spmi_pmic_clkdiv_set_enable_state(clkdiv, false); + spin_unlock_irqrestore(&clkdiv->lock, flags); +} + +static long clk_spmi_pmic_div_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + unsigned int div, div_factor; + + div = DIV_ROUND_UP(*parent_rate, rate); + div_factor = div_to_div_factor(div); + div = div_factor_to_div(div_factor); + + return *parent_rate / div; +} + +static unsigned long +clk_spmi_pmic_div_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) +{ + struct clkdiv *clkdiv = to_clkdiv(hw); + unsigned int div_factor; + + regmap_read(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, &div_factor); + div_factor &= DIV_CTL1_DIV_FACTOR_MASK; + + return parent_rate / div_factor_to_div(div_factor); +} + +static int clk_spmi_pmic_div_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clkdiv *clkdiv = to_clkdiv(hw); + unsigned int div_factor = div_to_div_factor(parent_rate / rate); + unsigned long flags; + bool enabled; + int ret; + + spin_lock_irqsave(&clkdiv->lock, flags); + enabled = is_spmi_pmic_clkdiv_enabled(clkdiv); + if (enabled) { + ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, false); + if (ret) + goto unlock; + } + + ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1, + DIV_CTL1_DIV_FACTOR_MASK, div_factor); + if (ret) + goto unlock; + + if (enabled) + ret = __spmi_pmic_clkdiv_set_enable_state(clkdiv, true, + div_factor); + +unlock: + spin_unlock_irqrestore(&clkdiv->lock, flags); + + return ret; +} + +static const struct clk_ops clk_spmi_pmic_div_ops = { + .enable = clk_spmi_pmic_div_enable, + .disable = clk_spmi_pmic_div_disable, + .set_rate = clk_spmi_pmic_div_set_rate, + .recalc_rate = clk_spmi_pmic_div_recalc_rate, + .round_rate = clk_spmi_pmic_div_round_rate, +}; + +struct spmi_pmic_div_clk_cc { + int nclks; + struct clkdiv clks[] __counted_by(nclks); +}; + +static struct clk_hw * +spmi_pmic_div_clk_hw_get(struct of_phandle_args *clkspec, void *data) +{ + struct spmi_pmic_div_clk_cc *cc = data; + int idx = clkspec->args[0] - 1; /* Start at 1 instead of 0 */ + + if (idx < 0 || idx >= cc->nclks) { + pr_err("%s: index value %u is invalid; allowed range [1, %d]\n", + __func__, clkspec->args[0], cc->nclks); + return ERR_PTR(-EINVAL); + } + + return &cc->clks[idx].hw; +} + +static int spmi_pmic_clkdiv_probe(struct platform_device *pdev) +{ + struct spmi_pmic_div_clk_cc *cc; + struct clk_init_data init = {}; + struct clkdiv *clkdiv; + struct clk *cxo; + struct regmap *regmap; + struct device *dev = &pdev->dev; + struct device_node *of_node = dev->of_node; + struct clk_parent_data parent_data = { .index = 0, }; + int nclks, i, ret, cxo_hz; + char name[20]; + u32 start; + + ret = of_property_read_u32(of_node, "reg", &start); + if (ret < 0) { + dev_err(dev, "reg property reading failed\n"); + return ret; + } + + regmap = dev_get_regmap(dev->parent, NULL); + if (!regmap) { + dev_err(dev, "Couldn't get parent's regmap\n"); + return -EINVAL; + } + + ret = of_property_read_u32(of_node, "qcom,num-clkdivs", &nclks); + if (ret < 0) { + dev_err(dev, "qcom,num-clkdivs property reading failed, ret=%d\n", + ret); + return ret; + } + + if (!nclks) + return -EINVAL; + + cc = devm_kzalloc(dev, struct_size(cc, clks, nclks), GFP_KERNEL); + if (!cc) + return -ENOMEM; + cc->nclks = nclks; + + cxo = clk_get(dev, "xo"); + if (IS_ERR(cxo)) { + ret = PTR_ERR(cxo); + if (ret != -EPROBE_DEFER) + dev_err(dev, "failed to get xo clock\n"); + return ret; + } + cxo_hz = clk_get_rate(cxo); + clk_put(cxo); + + init.name = name; + init.parent_data = &parent_data; + init.num_parents = 1; + init.ops = &clk_spmi_pmic_div_ops; + + for (i = 0, clkdiv = cc->clks; i < nclks; i++) { + snprintf(name, sizeof(name), "div_clk%d", i + 1); + + spin_lock_init(&clkdiv[i].lock); + clkdiv[i].base = start + i * 0x100; + clkdiv[i].regmap = regmap; + clkdiv[i].cxo_period_ns = NSEC_PER_SEC / cxo_hz; + clkdiv[i].hw.init = &init; + + ret = devm_clk_hw_register(dev, &clkdiv[i].hw); + if (ret) + return ret; + } + + return devm_of_clk_add_hw_provider(dev, spmi_pmic_div_clk_hw_get, cc); +} + +static const struct of_device_id spmi_pmic_clkdiv_match_table[] = { + { .compatible = "qcom,spmi-clkdiv" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, spmi_pmic_clkdiv_match_table); + +static struct platform_driver spmi_pmic_clkdiv_driver = { + .driver = { + .name = "qcom,spmi-pmic-clkdiv", + .of_match_table = spmi_pmic_clkdiv_match_table, + }, + .probe = spmi_pmic_clkdiv_probe, +}; +module_platform_driver(spmi_pmic_clkdiv_driver); + +MODULE_DESCRIPTION("QCOM SPMI PMIC clkdiv driver"); +MODULE_LICENSE("GPL v2"); |