summaryrefslogtreecommitdiffstats
path: root/drivers/clk/clk-wm831x.c
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--drivers/clk/clk-wm831x.c403
1 files changed, 403 insertions, 0 deletions
diff --git a/drivers/clk/clk-wm831x.c b/drivers/clk/clk-wm831x.c
new file mode 100644
index 000000000..146769532
--- /dev/null
+++ b/drivers/clk/clk-wm831x.c
@@ -0,0 +1,403 @@
+/*
+ * WM831x clock control
+ *
+ * Copyright 2011-2 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ * 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/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/wm831x/core.h>
+
+struct wm831x_clk {
+ struct wm831x *wm831x;
+ struct clk_hw xtal_hw;
+ struct clk_hw fll_hw;
+ struct clk_hw clkout_hw;
+ bool xtal_ena;
+};
+
+static int wm831x_xtal_is_prepared(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ xtal_hw);
+
+ return clkdata->xtal_ena;
+}
+
+static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ xtal_hw);
+
+ if (clkdata->xtal_ena)
+ return 32768;
+ else
+ return 0;
+}
+
+static const struct clk_ops wm831x_xtal_ops = {
+ .is_prepared = wm831x_xtal_is_prepared,
+ .recalc_rate = wm831x_xtal_recalc_rate,
+};
+
+static const struct clk_init_data wm831x_xtal_init = {
+ .name = "xtal",
+ .ops = &wm831x_xtal_ops,
+};
+
+static const unsigned long wm831x_fll_auto_rates[] = {
+ 2048000,
+ 11289600,
+ 12000000,
+ 12288000,
+ 19200000,
+ 22579600,
+ 24000000,
+ 24576000,
+};
+
+static int wm831x_fll_is_prepared(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ fll_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1);
+ if (ret < 0) {
+ dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n",
+ ret);
+ return true;
+ }
+
+ return (ret & WM831X_FLL_ENA) != 0;
+}
+
+static int wm831x_fll_prepare(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ fll_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1,
+ WM831X_FLL_ENA, WM831X_FLL_ENA);
+ if (ret != 0)
+ dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret);
+
+ /* wait 2-3 ms for new frequency taking effect */
+ usleep_range(2000, 3000);
+
+ return ret;
+}
+
+static void wm831x_fll_unprepare(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ fll_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_1, WM831X_FLL_ENA, 0);
+ if (ret != 0)
+ dev_crit(wm831x->dev, "Failed to disable FLL: %d\n", ret);
+}
+
+static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ fll_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
+ if (ret < 0) {
+ dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
+ ret);
+ return 0;
+ }
+
+ if (ret & WM831X_FLL_AUTO)
+ return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK];
+
+ dev_err(wm831x->dev, "FLL only supported in AUTO mode\n");
+
+ return 0;
+}
+
+static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *unused)
+{
+ int best = 0;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
+ if (abs(wm831x_fll_auto_rates[i] - rate) <
+ abs(wm831x_fll_auto_rates[best] - rate))
+ best = i;
+
+ return wm831x_fll_auto_rates[best];
+}
+
+static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ fll_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++)
+ if (wm831x_fll_auto_rates[i] == rate)
+ break;
+ if (i == ARRAY_SIZE(wm831x_fll_auto_rates))
+ return -EINVAL;
+
+ if (wm831x_fll_is_prepared(hw))
+ return -EPERM;
+
+ return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2,
+ WM831X_FLL_AUTO_FREQ_MASK, i);
+}
+
+static const char *wm831x_fll_parents[] = {
+ "xtal",
+ "clkin",
+};
+
+static u8 wm831x_fll_get_parent(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ fll_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ /* AUTO mode is always clocked from the crystal */
+ ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
+ if (ret < 0) {
+ dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
+ ret);
+ return 0;
+ }
+
+ if (ret & WM831X_FLL_AUTO)
+ return 0;
+
+ ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5);
+ if (ret < 0) {
+ dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n",
+ ret);
+ return 0;
+ }
+
+ switch (ret & WM831X_FLL_CLK_SRC_MASK) {
+ case 0:
+ return 0;
+ case 1:
+ return 1;
+ default:
+ dev_err(wm831x->dev, "Unsupported FLL clock source %d\n",
+ ret & WM831X_FLL_CLK_SRC_MASK);
+ return 0;
+ }
+}
+
+static const struct clk_ops wm831x_fll_ops = {
+ .is_prepared = wm831x_fll_is_prepared,
+ .prepare = wm831x_fll_prepare,
+ .unprepare = wm831x_fll_unprepare,
+ .round_rate = wm831x_fll_round_rate,
+ .recalc_rate = wm831x_fll_recalc_rate,
+ .set_rate = wm831x_fll_set_rate,
+ .get_parent = wm831x_fll_get_parent,
+};
+
+static const struct clk_init_data wm831x_fll_init = {
+ .name = "fll",
+ .ops = &wm831x_fll_ops,
+ .parent_names = wm831x_fll_parents,
+ .num_parents = ARRAY_SIZE(wm831x_fll_parents),
+ .flags = CLK_SET_RATE_GATE,
+};
+
+static int wm831x_clkout_is_prepared(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ clkout_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
+ if (ret < 0) {
+ dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
+ ret);
+ return false;
+ }
+
+ return (ret & WM831X_CLKOUT_ENA) != 0;
+}
+
+static int wm831x_clkout_prepare(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ clkout_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_reg_unlock(wm831x);
+ if (ret != 0) {
+ dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
+ return ret;
+ }
+
+ ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
+ WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA);
+ if (ret != 0)
+ dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret);
+
+ wm831x_reg_lock(wm831x);
+
+ return ret;
+}
+
+static void wm831x_clkout_unprepare(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ clkout_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_reg_unlock(wm831x);
+ if (ret != 0) {
+ dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret);
+ return;
+ }
+
+ ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
+ WM831X_CLKOUT_ENA, 0);
+ if (ret != 0)
+ dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret);
+
+ wm831x_reg_lock(wm831x);
+}
+
+static const char *wm831x_clkout_parents[] = {
+ "fll",
+ "xtal",
+};
+
+static u8 wm831x_clkout_get_parent(struct clk_hw *hw)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ clkout_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+ int ret;
+
+ ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1);
+ if (ret < 0) {
+ dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n",
+ ret);
+ return 0;
+ }
+
+ if (ret & WM831X_CLKOUT_SRC)
+ return 1;
+ else
+ return 0;
+}
+
+static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent)
+{
+ struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk,
+ clkout_hw);
+ struct wm831x *wm831x = clkdata->wm831x;
+
+ return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1,
+ WM831X_CLKOUT_SRC,
+ parent << WM831X_CLKOUT_SRC_SHIFT);
+}
+
+static const struct clk_ops wm831x_clkout_ops = {
+ .is_prepared = wm831x_clkout_is_prepared,
+ .prepare = wm831x_clkout_prepare,
+ .unprepare = wm831x_clkout_unprepare,
+ .get_parent = wm831x_clkout_get_parent,
+ .set_parent = wm831x_clkout_set_parent,
+};
+
+static const struct clk_init_data wm831x_clkout_init = {
+ .name = "clkout",
+ .ops = &wm831x_clkout_ops,
+ .parent_names = wm831x_clkout_parents,
+ .num_parents = ARRAY_SIZE(wm831x_clkout_parents),
+ .flags = CLK_SET_RATE_PARENT,
+};
+
+static int wm831x_clk_probe(struct platform_device *pdev)
+{
+ struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+ struct wm831x_clk *clkdata;
+ int ret;
+
+ clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
+ if (!clkdata)
+ return -ENOMEM;
+
+ clkdata->wm831x = wm831x;
+
+ /* XTAL_ENA can only be set via OTP/InstantConfig so just read once */
+ ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2);
+ if (ret < 0) {
+ dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n",
+ ret);
+ return ret;
+ }
+ clkdata->xtal_ena = ret & WM831X_XTAL_ENA;
+
+ clkdata->xtal_hw.init = &wm831x_xtal_init;
+ ret = devm_clk_hw_register(&pdev->dev, &clkdata->xtal_hw);
+ if (ret)
+ return ret;
+
+ clkdata->fll_hw.init = &wm831x_fll_init;
+ ret = devm_clk_hw_register(&pdev->dev, &clkdata->fll_hw);
+ if (ret)
+ return ret;
+
+ clkdata->clkout_hw.init = &wm831x_clkout_init;
+ ret = devm_clk_hw_register(&pdev->dev, &clkdata->clkout_hw);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, clkdata);
+
+ return 0;
+}
+
+static struct platform_driver wm831x_clk_driver = {
+ .probe = wm831x_clk_probe,
+ .driver = {
+ .name = "wm831x-clk",
+ },
+};
+
+module_platform_driver(wm831x_clk_driver);
+
+/* Module information */
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("WM831x clock driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm831x-clk");
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-01 00:49:10 +0000