diff options
Diffstat (limited to 'drivers/clk/clk-max9485.c')
| -rw-r--r-- | drivers/clk/clk-max9485.c | 386 |
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 0000000000..be9020b6c7 --- /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 = 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"); |