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path: root/drivers/clk/clk-max9485.c
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-rw-r--r--drivers/clk/clk-max9485.c386
1 files changed, 386 insertions, 0 deletions
diff --git a/drivers/clk/clk-max9485.c b/drivers/clk/clk-max9485.c
new file mode 100644
index 000000000..5f85b0a32
--- /dev/null
+++ b/drivers/clk/clk-max9485.c
@@ -0,0 +1,386 @@
+// 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)
+{
+ 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_new = 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");