new file mode 100644
@@ -0,0 +1,59 @@
+Devicetree bindings for Maxim MAX9485 Programmable Audio Clock Generator
+
+The driver for this device exposes 4 clocks in total:
+
+- MAX9485_MCLKOUT: A gated, buffered output of the input clock of 27 MHz
+- MAX9485_CLKOUT: A PLL that can be configured to 16 different discrete
+ frequencies
+- MAX9485_CLKOUT[1,2]: Two gated outputs for MAX9485_CLKOUT
+
+MAX9485_CLKOUT[1,2] are children of MAX9485_CLKOUT which upchain all rate set
+requests.
+
+Required properties:
+- compatible: "maxim,max9485"
+- clocks: Input clock, must provice 27.000 MHz
+- clock-names: Must be set to "xclk"
+- #clock-cells: From common clock binding; shall be set to 1
+
+Optional properties:
+- reset-gpio: GPIO descriptor connected to the #RESET input pin
+- vdd-supply: A regulator node for Vdd
+- clock-output-names: Name of output clocks, as defined in common clock
+ bindings
+
+If not explicitly set, the output names are "mclkout", "clkout", "clkout1"
+and "clkout2".
+
+Clocks are defined as preprocessor macros in the dt-binding header.
+
+Example:
+
+ #include <dt-bindings/clock/maxim,max9485.h>
+
+ xo_27mhz: xo_27mhz {
+ compatible = "fixed-clock";
+ #clock-cells = <0>;
+ clock-frequency = <27000000>;
+ };
+
+ &i2c0 {
+ max9485: max9485@63 {
+ compatible = "maxim,max9485";
+ clock-names = "xclk";
+ clocks = <&xo_27mhz>;
+ reg = <0x63>;
+ reset-gpios = <&gpio 1 GPIO_ACTIVE_HIGH>;
+ vdd-supply = <&3v3_reg>;
+ #clock-cells = <1>;
+ };
+ };
+
+ // Clock consumer node
+
+ foo@0 {
+ compatible = "bar,foo";
+ /* ... */
+ clock-names = "foo-intput-clk";
+ clocks = <&max9485 MAX9485_CLKOUT1>;
+ };
@@ -45,6 +45,14 @@ config COMMON_CLK_MAX77686
This driver supports Maxim 77620/77686/77802 crystal oscillator
clock.
+config COMMON_CLK_MAX9485
+ tristate "Clock driver for Maxim 9485 Programmable Clock Generator"
+ depends on I2C
+ depends on OF
+ depends on GPIOLIB || COMPILE_TEST
+ ---help---
+ This driver supports Maxim 9485 Programmable Audio Clock Generator
+
config COMMON_CLK_RK808
tristate "Clock driver for RK805/RK808/RK818"
depends on MFD_RK808
@@ -31,6 +31,7 @@ obj-$(CONFIG_COMMON_CLK_ASPEED) += clk-aspeed.o
obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o
obj-$(CONFIG_CLK_HSDK) += clk-hsdk-pll.o
obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o
+obj-$(CONFIG_COMMON_CLK_MAX9485) += clk-max9485.o
obj-$(CONFIG_ARCH_MOXART) += clk-moxart.o
obj-$(CONFIG_ARCH_NOMADIK) += clk-nomadik.o
obj-$(CONFIG_ARCH_NSPIRE) += clk-nspire.o
new file mode 100644
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * clk-max9485.c: MAX9485 Programmable Audio Clock Generator
+ *
+ * (c) 2018 Daniel Mack <daniel@zonque.org>
+ *
+ * References:
+ * MAX9485 Datasheet
+ * http://www.maximintegrated.com/datasheet/index.mvp/id/4421
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/clkdev.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_INPUT_FREQ 27000000UL
+#define MAX9485_NUM_CLKS 4
+
+/* This chip has only one register of 8 bit width. */
+
+enum {
+ MAX9485_FS_12KHZ = 0 << 0,
+ MAX9485_FS_32KHZ = 1 << 0,
+ MAX9485_FS_44_1KHZ = 2 << 0,
+ MAX9485_FS_48KHZ = 3 << 0,
+};
+
+enum {
+ MAX9485_SCALE_256 = 0 << 2,
+ MAX9485_SCALE_384 = 1 << 2,
+ 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, only the one with lowest jitter is listed.
+ */
+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 },
+ { 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 },
+ { 33868800, MAX9485_FS_44_1KHZ | MAX9485_SCALE_384 | MAX9485_DOUBLE },
+ { 36864000, MAX9485_FS_48KHZ | MAX9485_SCALE_384 | MAX9485_DOUBLE },
+ { 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;
+ unsigned long clkout_rate;
+ struct regulator *supply;
+ struct gpio_desc *reset_gpio;
+ struct max9485_clk_hw hw[MAX9485_NUM_CLKS];
+
+ struct {
+ struct clk_hw_onecell_data data;
+ struct clk_hw *hw[MAX9485_NUM_CLKS];
+ } onecell;
+};
+
+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 %02x value %02x -> %02x\n",
+ mask, value, drvdata->reg_value);
+
+ ret = i2c_master_send(drvdata->client,
+ &drvdata->reg_value,
+ sizeof(drvdata->reg_value));
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int max9485_clk_prepare(struct clk_hw *hw)
+{
+ struct max9485_clk_hw *clk_hw =
+ container_of(hw, struct max9485_clk_hw, 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 =
+ container_of(hw, struct max9485_clk_hw, hw);
+
+ max9485_update_bits(clk_hw->drvdata, clk_hw->enable_bit, 0);
+}
+
+/*
+ * MCLK OUT
+ */
+
+/* The MCLK output can only provide the same rate as the input clock */
+static unsigned long max9485_mclkout_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return MAX9485_INPUT_FREQ;
+}
+
+/*
+ * CLKOUT - configurable clock output
+ */
+static int max9485_clkout_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ const struct max9485_rate *entry;
+ struct max9485_clk_hw *clk_hw =
+ container_of(hw, struct max9485_clk_hw, hw);
+
+ for (entry = max9485_rates; entry->out != 0; entry++)
+ if (entry->out == rate)
+ break;
+
+ if (entry->out == 0)
+ return -EINVAL;
+
+ clk_hw->drvdata->clkout_rate = rate;
+
+ return max9485_update_bits(clk_hw->drvdata,
+ MAX9485_FREQ_MASK,
+ entry->reg_value);
+}
+
+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;
+}
+
+static unsigned long max9485_clkout_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct max9485_clk_hw *clk_hw =
+ container_of(hw, struct max9485_clk_hw, hw);
+
+ return clk_hw->drvdata->clkout_rate;
+}
+
+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,
+ .recalc_rate = max9485_mclkout_recalc_rate,
+ },
+ },
+ [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,
+ .recalc_rate = max9485_clkout_recalc_rate,
+ },
+ },
+ [MAX9485_CLKOUT2] = {
+ .name = "clkout2",
+ .parent_index = MAX9485_CLKOUT,
+ .enable_bit = MAX9485_CLKOUT2_ENABLE,
+ .ops = {
+ .prepare = max9485_clk_prepare,
+ .unprepare = max9485_clk_unprepare,
+ .recalc_rate = max9485_clkout_recalc_rate,
+ },
+ },
+};
+
+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;
+ unsigned long freq;
+ int i, ret;
+
+ drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
+ if (drvdata == NULL)
+ return -ENOMEM;
+
+ drvdata->xclk = devm_clk_get(dev, "xclk");
+ if (IS_ERR(drvdata->xclk))
+ return PTR_ERR(drvdata->xclk);
+
+ freq = clk_get_rate(drvdata->xclk);
+ if (freq != MAX9485_INPUT_FREQ) {
+ dev_err(dev, "Illegal xclk frequency of %ld\n", freq);
+ return -EINVAL;
+ }
+
+ 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;
+
+ 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.flags = CLK_IS_BASIC;
+
+ if (parent_index > 0) {
+ drvdata->hw[i].init.parent_names =
+ &drvdata->hw[parent_index].init.name;
+ drvdata->hw[i].init.num_parents = 1;
+ drvdata->hw[i].init.flags |= CLK_SET_RATE_PARENT;
+ }
+
+ 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;
+
+ drvdata->onecell.hw[i] = &drvdata->hw[i].hw;
+ }
+
+ drvdata->onecell.data.num = MAX9485_NUM_CLKS;
+
+ return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+ &drvdata->onecell.data);
+}
+
+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",
+ .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");
new file mode 100644
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Daniel Mack
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef __DT_BINDINGS_MAX9485_CLK_H
+#define __DT_BINDINGS_MAX9485_CLK_H
+
+#define MAX9485_MCLKOUT 0
+#define MAX9485_CLKOUT 1
+#define MAX9485_CLKOUT1 2
+#define MAX9485_CLKOUT2 3
+
+#endif /* __DT_BINDINGS_MAX9485_CLK_H */