1 files changed, 387 insertions, 0 deletions

diff --git a/drivers/clk/clk-max9485.c b/drivers/clk/clk-max9485.c
new file mode 100644
index 000000000..5e80f3d09
--- /dev/null
+++ b/drivers/clk/clk-max9485.c
@@ -0,0 +1,387 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/regulator/consumer.h>
+
+#include <dt-bindings/clock/maxim,max9485.h>
+
+#define MAX9485_NUM_CLKS 4
+
+/* This chip has only one register of 8 bit width. */
+
+#define MAX9485_FS_12KHZ	(0 << 0)
+#define MAX9485_FS_32KHZ	(1 << 0)
+#define MAX9485_FS_44_1KHZ	(2 << 0)
+#define MAX9485_FS_48KHZ	(3 << 0)
+
+#define MAX9485_SCALE_256	(0 << 2)
+#define MAX9485_SCALE_384	(1 << 2)
+#define MAX9485_SCALE_768	(2 << 2)
+
+#define MAX9485_DOUBLE		BIT(4)
+#define MAX9485_CLKOUT1_ENABLE	BIT(5)
+#define MAX9485_CLKOUT2_ENABLE	BIT(6)
+#define MAX9485_MCLK_ENABLE	BIT(7)
+#define MAX9485_FREQ_MASK	0x1f
+
+struct max9485_rate {
+	unsigned long out;
+	u8 reg_value;
+};
+
+/*
+ * Ordered by frequency. For frequency the hardware can generate with
+ * multiple settings, the one with lowest jitter is listed first.
+ */
+static const struct max9485_rate max9485_rates[] = {
+	{  3072000, MAX9485_FS_12KHZ   | MAX9485_SCALE_256 },
+	{  4608000, MAX9485_FS_12KHZ   | MAX9485_SCALE_384 },
+	{  8192000, MAX9485_FS_32KHZ   | MAX9485_SCALE_256 },
+	{  9126000, MAX9485_FS_12KHZ   | MAX9485_SCALE_768 },
+	{ 11289600, MAX9485_FS_44_1KHZ | MAX9485_SCALE_256 },
+	{ 12288000, MAX9485_FS_48KHZ   | MAX9485_SCALE_256 },
+	{ 12288000, MAX9485_FS_32KHZ   | MAX9485_SCALE_384 },
+	{ 16384000, MAX9485_FS_32KHZ   | MAX9485_SCALE_256 | MAX9485_DOUBLE },
+	{ 16934400, MAX9485_FS_44_1KHZ | MAX9485_SCALE_384 },
+	{ 18384000, MAX9485_FS_48KHZ   | MAX9485_SCALE_384 },
+	{ 22579200, MAX9485_FS_44_1KHZ | MAX9485_SCALE_256 | MAX9485_DOUBLE },
+	{ 24576000, MAX9485_FS_48KHZ   | MAX9485_SCALE_256 | MAX9485_DOUBLE },
+	{ 24576000, MAX9485_FS_32KHZ   | MAX9485_SCALE_384 | MAX9485_DOUBLE },
+	{ 24576000, MAX9485_FS_32KHZ   | MAX9485_SCALE_768 },
+	{ 33868800, MAX9485_FS_44_1KHZ | MAX9485_SCALE_384 | MAX9485_DOUBLE },
+	{ 33868800, MAX9485_FS_44_1KHZ | MAX9485_SCALE_768 },
+	{ 36864000, MAX9485_FS_48KHZ   | MAX9485_SCALE_384 | MAX9485_DOUBLE },
+	{ 36864000, MAX9485_FS_48KHZ   | MAX9485_SCALE_768 },
+	{ 49152000, MAX9485_FS_32KHZ   | MAX9485_SCALE_768 | MAX9485_DOUBLE },
+	{ 67737600, MAX9485_FS_44_1KHZ | MAX9485_SCALE_768 | MAX9485_DOUBLE },
+	{ 73728000, MAX9485_FS_48KHZ   | MAX9485_SCALE_768 | MAX9485_DOUBLE },
+	{ } /* sentinel */
+};
+
+struct max9485_driver_data;
+
+struct max9485_clk_hw {
+	struct clk_hw hw;
+	struct clk_init_data init;
+	u8 enable_bit;
+	struct max9485_driver_data *drvdata;
+};
+
+struct max9485_driver_data {
+	struct clk *xclk;
+	struct i2c_client *client;
+	u8 reg_value;
+	struct regulator *supply;
+	struct gpio_desc *reset_gpio;
+	struct max9485_clk_hw hw[MAX9485_NUM_CLKS];
+};
+
+static inline struct max9485_clk_hw *to_max9485_clk(struct clk_hw *hw)
+{
+	return container_of(hw, struct max9485_clk_hw, hw);
+}
+
+static int max9485_update_bits(struct max9485_driver_data *drvdata,
+			       u8 mask, u8 value)
+{
+	int ret;
+
+	drvdata->reg_value &= ~mask;
+	drvdata->reg_value |= value;
+
+	dev_dbg(&drvdata->client->dev,
+		"updating mask 0x%02x value 0x%02x -> 0x%02x\n",
+		mask, value, drvdata->reg_value);
+
+	ret = i2c_master_send(drvdata->client,
+			      &drvdata->reg_value,
+			      sizeof(drvdata->reg_value));
+
+	return ret < 0 ? ret : 0;
+}
+
+static int max9485_clk_prepare(struct clk_hw *hw)
+{
+	struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
+
+	return max9485_update_bits(clk_hw->drvdata,
+				   clk_hw->enable_bit,
+				   clk_hw->enable_bit);
+}
+
+static void max9485_clk_unprepare(struct clk_hw *hw)
+{
+	struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
+
+	max9485_update_bits(clk_hw->drvdata, clk_hw->enable_bit, 0);
+}
+
+/*
+ * CLKOUT - configurable clock output
+ */
+static int max9485_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long parent_rate)
+{
+	struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
+	const struct max9485_rate *entry;
+
+	for (entry = max9485_rates; entry->out != 0; entry++)
+		if (entry->out == rate)
+			break;
+
+	if (entry->out == 0)
+		return -EINVAL;
+
+	return max9485_update_bits(clk_hw->drvdata,
+				   MAX9485_FREQ_MASK,
+				   entry->reg_value);
+}
+
+static unsigned long max9485_clkout_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	struct max9485_clk_hw *clk_hw = to_max9485_clk(hw);
+	struct max9485_driver_data *drvdata = clk_hw->drvdata;
+	u8 val = drvdata->reg_value & MAX9485_FREQ_MASK;
+	const struct max9485_rate *entry;
+
+	for (entry = max9485_rates; entry->out != 0; entry++)
+		if (val == entry->reg_value)
+			return entry->out;
+
+	return 0;
+}
+
+static long max9485_clkout_round_rate(struct clk_hw *hw, unsigned long rate,
+				      unsigned long *parent_rate)
+{
+	const struct max9485_rate *curr, *prev = NULL;
+
+	for (curr = max9485_rates; curr->out != 0; curr++) {
+		/* Exact matches */
+		if (curr->out == rate)
+			return rate;
+
+		/*
+		 * Find the first entry that has a frequency higher than the
+		 * requested one.
+		 */
+		if (curr->out > rate) {
+			unsigned int mid;
+
+			/*
+			 * If this is the first entry, clamp the value to the
+			 * lowest possible frequency.
+			 */
+			if (!prev)
+				return curr->out;
+
+			/*
+			 * Otherwise, determine whether the previous entry or
+			 * current one is closer.
+			 */
+			mid = prev->out + ((curr->out - prev->out) / 2);
+
+			return (mid > rate) ? prev->out : curr->out;
+		}
+
+		prev = curr;
+	}
+
+	/* If the last entry was still too high, clamp the value */
+	return prev->out;
+}
+
+struct max9485_clk {
+	const char *name;
+	int parent_index;
+	const struct clk_ops ops;
+	u8 enable_bit;
+};
+
+static const struct max9485_clk max9485_clks[MAX9485_NUM_CLKS] = {
+	[MAX9485_MCLKOUT] = {
+		.name = "mclkout",
+		.parent_index = -1,
+		.enable_bit = MAX9485_MCLK_ENABLE,
+		.ops = {
+			.prepare	= max9485_clk_prepare,
+			.unprepare	= max9485_clk_unprepare,
+		},
+	},
+	[MAX9485_CLKOUT] = {
+		.name = "clkout",
+		.parent_index = -1,
+		.ops = {
+			.set_rate	= max9485_clkout_set_rate,
+			.round_rate	= max9485_clkout_round_rate,
+			.recalc_rate	= max9485_clkout_recalc_rate,
+		},
+	},
+	[MAX9485_CLKOUT1] = {
+		.name = "clkout1",
+		.parent_index = MAX9485_CLKOUT,
+		.enable_bit = MAX9485_CLKOUT1_ENABLE,
+		.ops = {
+			.prepare	= max9485_clk_prepare,
+			.unprepare	= max9485_clk_unprepare,
+		},
+	},
+	[MAX9485_CLKOUT2] = {
+		.name = "clkout2",
+		.parent_index = MAX9485_CLKOUT,
+		.enable_bit = MAX9485_CLKOUT2_ENABLE,
+		.ops = {
+			.prepare	= max9485_clk_prepare,
+			.unprepare	= max9485_clk_unprepare,
+		},
+	},
+};
+
+static struct clk_hw *
+max9485_of_clk_get(struct of_phandle_args *clkspec, void *data)
+{
+	struct max9485_driver_data *drvdata = data;
+	unsigned int idx = clkspec->args[0];
+
+	return &drvdata->hw[idx].hw;
+}
+
+static int max9485_i2c_probe(struct i2c_client *client,
+			     const struct i2c_device_id *id)
+{
+	struct max9485_driver_data *drvdata;
+	struct device *dev = &client->dev;
+	const char *xclk_name;
+	int i, ret;
+
+	drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+	if (!drvdata)
+		return -ENOMEM;
+
+	drvdata->xclk = devm_clk_get(dev, "xclk");
+	if (IS_ERR(drvdata->xclk))
+		return PTR_ERR(drvdata->xclk);
+
+	xclk_name = __clk_get_name(drvdata->xclk);
+
+	drvdata->supply = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(drvdata->supply))
+		return PTR_ERR(drvdata->supply);
+
+	ret = regulator_enable(drvdata->supply);
+	if (ret < 0)
+		return ret;
+
+	drvdata->reset_gpio =
+		devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(drvdata->reset_gpio))
+		return PTR_ERR(drvdata->reset_gpio);
+
+	i2c_set_clientdata(client, drvdata);
+	drvdata->client = client;
+
+	ret = i2c_master_recv(drvdata->client, &drvdata->reg_value,
+			      sizeof(drvdata->reg_value));
+	if (ret < 0) {
+		dev_warn(dev, "Unable to read device register: %d\n", ret);
+		return ret;
+	}
+
+	for (i = 0; i < MAX9485_NUM_CLKS; i++) {
+		int parent_index = max9485_clks[i].parent_index;
+		const char *name;
+
+		if (of_property_read_string_index(dev->of_node,
+						  "clock-output-names",
+						  i, &name) == 0) {
+			drvdata->hw[i].init.name = name;
+		} else {
+			drvdata->hw[i].init.name = max9485_clks[i].name;
+		}
+
+		drvdata->hw[i].init.ops = &max9485_clks[i].ops;
+		drvdata->hw[i].init.num_parents = 1;
+		drvdata->hw[i].init.flags = 0;
+
+		if (parent_index > 0) {
+			drvdata->hw[i].init.parent_names =
+				&drvdata->hw[parent_index].init.name;
+			drvdata->hw[i].init.flags |= CLK_SET_RATE_PARENT;
+		} else {
+			drvdata->hw[i].init.parent_names = &xclk_name;
+		}
+
+		drvdata->hw[i].enable_bit = max9485_clks[i].enable_bit;
+		drvdata->hw[i].hw.init = &drvdata->hw[i].init;
+		drvdata->hw[i].drvdata = drvdata;
+
+		ret = devm_clk_hw_register(dev, &drvdata->hw[i].hw);
+		if (ret < 0)
+			return ret;
+	}
+
+	return devm_of_clk_add_hw_provider(dev, max9485_of_clk_get, drvdata);
+}
+
+static int __maybe_unused max9485_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct max9485_driver_data *drvdata = i2c_get_clientdata(client);
+
+	gpiod_set_value_cansleep(drvdata->reset_gpio, 0);
+
+	return 0;
+}
+
+static int __maybe_unused max9485_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct max9485_driver_data *drvdata = i2c_get_clientdata(client);
+	int ret;
+
+	gpiod_set_value_cansleep(drvdata->reset_gpio, 1);
+
+	ret = i2c_master_send(client, &drvdata->reg_value,
+			      sizeof(drvdata->reg_value));
+
+	return ret < 0 ? ret : 0;
+}
+
+static const struct dev_pm_ops max9485_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(max9485_suspend, max9485_resume)
+};
+
+static const struct of_device_id max9485_dt_ids[] = {
+	{ .compatible = "maxim,max9485", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max9485_dt_ids);
+
+static const struct i2c_device_id max9485_i2c_ids[] = {
+	{ .name = "max9485", },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max9485_i2c_ids);
+
+static struct i2c_driver max9485_driver = {
+	.driver = {
+		.name		= "max9485",
+		.pm		= &max9485_pm_ops,
+		.of_match_table	= max9485_dt_ids,
+	},
+	.probe = max9485_i2c_probe,
+	.id_table = max9485_i2c_ids,
+};
+module_i2c_driver(max9485_driver);
+
+MODULE_AUTHOR("Daniel Mack <daniel@zonque.org>");
+MODULE_DESCRIPTION("MAX9485 Programmable Audio Clock Generator");
+MODULE_LICENSE("GPL v2");