#include <linux/bitops.h>
#include <linux/cleanup.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 int clk_spmi_pmic_div_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
unsigned int div, div_factor;
div = DIV_ROUND_UP(req->best_parent_rate, req->rate);
div_factor = div_to_div_factor(div);
div = div_factor_to_div(div_factor);
req->rate = req->best_parent_rate / div;
return 0;
}
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);
bool enabled;
int ret;
guard(spinlock_irqsave)(&clkdiv->lock);
enabled = is_spmi_pmic_clkdiv_enabled(clkdiv);
if (enabled) {
ret = spmi_pmic_clkdiv_set_enable_state(clkdiv, false);
if (ret)
return ret;
}
ret = regmap_update_bits(clkdiv->regmap, clkdiv->base + REG_DIV_CTL1,
DIV_CTL1_DIV_FACTOR_MASK, div_factor);
if (ret)
return ret;
if (enabled)
ret = __spmi_pmic_clkdiv_set_enable_state(clkdiv, true,
div_factor);
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,
.determine_rate = clk_spmi_pmic_div_determine_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;
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" },
{ }
};
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");
