1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/clk/clk-twl6040.c b/drivers/clk/clk-twl6040.c
new file mode 100644
index 000000000..b8d1cfe5b
--- /dev/null
+++ b/drivers/clk/clk-twl6040.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+* TWL6040 clock module driver for OMAP4 McPDM functional clock
+*
+* Copyright (C) 2012 Texas Instruments Inc.
+* Peter Ujfalusi <peter.ujfalusi@ti.com>
+*/
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/twl6040.h>
+#include <linux/clk-provider.h>
+
+struct twl6040_pdmclk {
+	struct twl6040 *twl6040;
+	struct device *dev;
+	struct clk_hw pdmclk_hw;
+	int enabled;
+};
+
+static int twl6040_pdmclk_is_prepared(struct clk_hw *hw)
+{
+	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
+						     pdmclk_hw);
+
+	return pdmclk->enabled;
+}
+
+static int twl6040_pdmclk_reset_one_clock(struct twl6040_pdmclk *pdmclk,
+					  unsigned int reg)
+{
+	const u8 reset_mask = TWL6040_HPLLRST;	/* Same for HPPLL and LPPLL */
+	int ret;
+
+	ret = twl6040_set_bits(pdmclk->twl6040, reg, reset_mask);
+	if (ret < 0)
+		return ret;
+
+	ret = twl6040_clear_bits(pdmclk->twl6040, reg, reset_mask);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * TWL6040A2 Phoenix Audio IC erratum #6: "PDM Clock Generation Issue At
+ * Cold Temperature". This affects cold boot and deeper idle states it
+ * seems. The workaround consists of resetting HPPLL and LPPLL.
+ */
+static int twl6040_pdmclk_quirk_reset_clocks(struct twl6040_pdmclk *pdmclk)
+{
+	int ret;
+
+	ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_HPPLLCTL);
+	if (ret)
+		return ret;
+
+	ret = twl6040_pdmclk_reset_one_clock(pdmclk, TWL6040_REG_LPPLLCTL);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int twl6040_pdmclk_prepare(struct clk_hw *hw)
+{
+	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
+						     pdmclk_hw);
+	int ret;
+
+	ret = twl6040_power(pdmclk->twl6040, 1);
+	if (ret)
+		return ret;
+
+	ret = twl6040_pdmclk_quirk_reset_clocks(pdmclk);
+	if (ret)
+		goto out_err;
+
+	pdmclk->enabled = 1;
+
+	return 0;
+
+out_err:
+	dev_err(pdmclk->dev, "%s: error %i\n", __func__, ret);
+	twl6040_power(pdmclk->twl6040, 0);
+
+	return ret;
+}
+
+static void twl6040_pdmclk_unprepare(struct clk_hw *hw)
+{
+	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
+						     pdmclk_hw);
+	int ret;
+
+	ret = twl6040_power(pdmclk->twl6040, 0);
+	if (!ret)
+		pdmclk->enabled = 0;
+
+}
+
+static unsigned long twl6040_pdmclk_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	struct twl6040_pdmclk *pdmclk = container_of(hw, struct twl6040_pdmclk,
+						     pdmclk_hw);
+
+	return twl6040_get_sysclk(pdmclk->twl6040);
+}
+
+static const struct clk_ops twl6040_pdmclk_ops = {
+	.is_prepared = twl6040_pdmclk_is_prepared,
+	.prepare = twl6040_pdmclk_prepare,
+	.unprepare = twl6040_pdmclk_unprepare,
+	.recalc_rate = twl6040_pdmclk_recalc_rate,
+};
+
+static const struct clk_init_data twl6040_pdmclk_init = {
+	.name = "pdmclk",
+	.ops = &twl6040_pdmclk_ops,
+	.flags = CLK_GET_RATE_NOCACHE,
+};
+
+static int twl6040_pdmclk_probe(struct platform_device *pdev)
+{
+	struct twl6040 *twl6040 = dev_get_drvdata(pdev->dev.parent);
+	struct twl6040_pdmclk *clkdata;
+	int ret;
+
+	clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL);
+	if (!clkdata)
+		return -ENOMEM;
+
+	clkdata->dev = &pdev->dev;
+	clkdata->twl6040 = twl6040;
+
+	clkdata->pdmclk_hw.init = &twl6040_pdmclk_init;
+	ret = devm_clk_hw_register(&pdev->dev, &clkdata->pdmclk_hw);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, clkdata);
+
+	return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,
+					   &clkdata->pdmclk_hw);
+}
+
+static struct platform_driver twl6040_pdmclk_driver = {
+	.driver = {
+		.name = "twl6040-pdmclk",
+	},
+	.probe = twl6040_pdmclk_probe,
+};
+
+module_platform_driver(twl6040_pdmclk_driver);
+
+MODULE_DESCRIPTION("TWL6040 clock driver for McPDM functional clock");
+MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
+MODULE_ALIAS("platform:twl6040-pdmclk");
+MODULE_LICENSE("GPL");