1 files changed, 382 insertions, 0 deletions
diff --git a/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c b/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c
new file mode 100644
index 000000000..d65398497
--- /dev/null
+++ b/drivers/clk/sunxi-ng/ccu-sun6i-rtc.c
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright (c) 2021 Samuel Holland <samuel@sholland.org>
+//
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#include <linux/clk/sunxi-ng.h>
+
+#include "ccu_common.h"
+
+#include "ccu_div.h"
+#include "ccu_gate.h"
+#include "ccu_mux.h"
+
+#include "ccu-sun6i-rtc.h"
+
+#define IOSC_ACCURACY			300000000 /* 30% */
+#define IOSC_RATE			16000000
+
+#define LOSC_RATE			32768
+#define LOSC_RATE_SHIFT			15
+
+#define LOSC_CTRL_REG			0x0
+#define LOSC_CTRL_KEY			0x16aa0000
+
+#define IOSC_32K_CLK_DIV_REG		0x8
+#define IOSC_32K_CLK_DIV		GENMASK(4, 0)
+#define IOSC_32K_PRE_DIV		32
+
+#define IOSC_CLK_CALI_REG		0xc
+#define IOSC_CLK_CALI_DIV_ONES		22
+#define IOSC_CLK_CALI_EN		BIT(1)
+#define IOSC_CLK_CALI_SRC_SEL		BIT(0)
+
+#define LOSC_OUT_GATING_REG		0x60
+
+#define DCXO_CTRL_REG			0x160
+#define DCXO_CTRL_CLK16M_RC_EN		BIT(0)
+
+struct sun6i_rtc_match_data {
+	bool				have_ext_osc32k		: 1;
+	bool				have_iosc_calibration	: 1;
+	bool				rtc_32k_single_parent	: 1;
+	const struct clk_parent_data	*osc32k_fanout_parents;
+	u8				osc32k_fanout_nparents;
+};
+
+static bool have_iosc_calibration;
+
+static int ccu_iosc_enable(struct clk_hw *hw)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+
+	return ccu_gate_helper_enable(cm, DCXO_CTRL_CLK16M_RC_EN);
+}
+
+static void ccu_iosc_disable(struct clk_hw *hw)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+
+	return ccu_gate_helper_disable(cm, DCXO_CTRL_CLK16M_RC_EN);
+}
+
+static int ccu_iosc_is_enabled(struct clk_hw *hw)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+
+	return ccu_gate_helper_is_enabled(cm, DCXO_CTRL_CLK16M_RC_EN);
+}
+
+static unsigned long ccu_iosc_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+
+	if (have_iosc_calibration) {
+		u32 reg = readl(cm->base + IOSC_CLK_CALI_REG);
+
+		/*
+		 * Recover the IOSC frequency by shifting the ones place of
+		 * (fixed-point divider * 32768) into bit zero.
+		 */
+		if (reg & IOSC_CLK_CALI_EN)
+			return reg >> (IOSC_CLK_CALI_DIV_ONES - LOSC_RATE_SHIFT);
+	}
+
+	return IOSC_RATE;
+}
+
+static unsigned long ccu_iosc_recalc_accuracy(struct clk_hw *hw,
+					      unsigned long parent_accuracy)
+{
+	return IOSC_ACCURACY;
+}
+
+static const struct clk_ops ccu_iosc_ops = {
+	.enable			= ccu_iosc_enable,
+	.disable		= ccu_iosc_disable,
+	.is_enabled		= ccu_iosc_is_enabled,
+	.recalc_rate		= ccu_iosc_recalc_rate,
+	.recalc_accuracy	= ccu_iosc_recalc_accuracy,
+};
+
+static struct ccu_common iosc_clk = {
+	.reg		= DCXO_CTRL_REG,
+	.hw.init	= CLK_HW_INIT_NO_PARENT("iosc", &ccu_iosc_ops,
+						CLK_GET_RATE_NOCACHE),
+};
+
+static int ccu_iosc_32k_prepare(struct clk_hw *hw)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+	u32 val;
+
+	if (!have_iosc_calibration)
+		return 0;
+
+	val = readl(cm->base + IOSC_CLK_CALI_REG);
+	writel(val | IOSC_CLK_CALI_EN | IOSC_CLK_CALI_SRC_SEL,
+	       cm->base + IOSC_CLK_CALI_REG);
+
+	return 0;
+}
+
+static void ccu_iosc_32k_unprepare(struct clk_hw *hw)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+	u32 val;
+
+	if (!have_iosc_calibration)
+		return;
+
+	val = readl(cm->base + IOSC_CLK_CALI_REG);
+	writel(val & ~(IOSC_CLK_CALI_EN | IOSC_CLK_CALI_SRC_SEL),
+	       cm->base + IOSC_CLK_CALI_REG);
+}
+
+static unsigned long ccu_iosc_32k_recalc_rate(struct clk_hw *hw,
+					      unsigned long parent_rate)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+	u32 val;
+
+	if (have_iosc_calibration) {
+		val = readl(cm->base + IOSC_CLK_CALI_REG);
+
+		/* Assume the calibrated 32k clock is accurate. */
+		if (val & IOSC_CLK_CALI_SRC_SEL)
+			return LOSC_RATE;
+	}
+
+	val = readl(cm->base + IOSC_32K_CLK_DIV_REG) & IOSC_32K_CLK_DIV;
+
+	return parent_rate / IOSC_32K_PRE_DIV / (val + 1);
+}
+
+static unsigned long ccu_iosc_32k_recalc_accuracy(struct clk_hw *hw,
+						  unsigned long parent_accuracy)
+{
+	struct ccu_common *cm = hw_to_ccu_common(hw);
+	u32 val;
+
+	if (have_iosc_calibration) {
+		val = readl(cm->base + IOSC_CLK_CALI_REG);
+
+		/* Assume the calibrated 32k clock is accurate. */
+		if (val & IOSC_CLK_CALI_SRC_SEL)
+			return 0;
+	}
+
+	return parent_accuracy;
+}
+
+static const struct clk_ops ccu_iosc_32k_ops = {
+	.prepare		= ccu_iosc_32k_prepare,
+	.unprepare		= ccu_iosc_32k_unprepare,
+	.recalc_rate		= ccu_iosc_32k_recalc_rate,
+	.recalc_accuracy	= ccu_iosc_32k_recalc_accuracy,
+};
+
+static struct ccu_common iosc_32k_clk = {
+	.hw.init	= CLK_HW_INIT_HW("iosc-32k", &iosc_clk.hw,
+					 &ccu_iosc_32k_ops,
+					 CLK_GET_RATE_NOCACHE),
+};
+
+static const struct clk_hw *ext_osc32k[] = { NULL }; /* updated during probe */
+
+static SUNXI_CCU_GATE_HWS(ext_osc32k_gate_clk, "ext-osc32k-gate",
+			  ext_osc32k, 0x0, BIT(4), 0);
+
+static const struct clk_hw *osc32k_parents[] = {
+	&iosc_32k_clk.hw,
+	&ext_osc32k_gate_clk.common.hw
+};
+
+static struct clk_init_data osc32k_init_data = {
+	.name		= "osc32k",
+	.ops		= &ccu_mux_ops,
+	.parent_hws	= osc32k_parents,
+	.num_parents	= ARRAY_SIZE(osc32k_parents), /* updated during probe */
+};
+
+static struct ccu_mux osc32k_clk = {
+	.mux	= _SUNXI_CCU_MUX(0, 1),
+	.common	= {
+		.reg		= LOSC_CTRL_REG,
+		.features	= CCU_FEATURE_KEY_FIELD,
+		.hw.init	= &osc32k_init_data,
+	},
+};
+
+/* This falls back to the global name for fwnodes without a named reference. */
+static const struct clk_parent_data osc24M[] = {
+	{ .fw_name = "hosc", .name = "osc24M" }
+};
+
+static struct ccu_gate osc24M_32k_clk = {
+	.enable	= BIT(16),
+	.common	= {
+		.reg		= LOSC_OUT_GATING_REG,
+		.prediv		= 750,
+		.features	= CCU_FEATURE_ALL_PREDIV,
+		.hw.init	= CLK_HW_INIT_PARENTS_DATA("osc24M-32k", osc24M,
+							   &ccu_gate_ops, 0),
+	},
+};
+
+static const struct clk_hw *rtc_32k_parents[] = {
+	&osc32k_clk.common.hw,
+	&osc24M_32k_clk.common.hw
+};
+
+static struct clk_init_data rtc_32k_init_data = {
+	.name		= "rtc-32k",
+	.ops		= &ccu_mux_ops,
+	.parent_hws	= rtc_32k_parents,
+	.num_parents	= ARRAY_SIZE(rtc_32k_parents), /* updated during probe */
+	.flags		= CLK_IS_CRITICAL,
+};
+
+static struct ccu_mux rtc_32k_clk = {
+	.mux	= _SUNXI_CCU_MUX(1, 1),
+	.common	= {
+		.reg		= LOSC_CTRL_REG,
+		.features	= CCU_FEATURE_KEY_FIELD,
+		.hw.init	= &rtc_32k_init_data,
+	},
+};
+
+static struct clk_init_data osc32k_fanout_init_data = {
+	.name		= "osc32k-fanout",
+	.ops		= &ccu_mux_ops,
+	/* parents are set during probe */
+};
+
+static struct ccu_mux osc32k_fanout_clk = {
+	.enable	= BIT(0),
+	.mux	= _SUNXI_CCU_MUX(1, 2),
+	.common	= {
+		.reg		= LOSC_OUT_GATING_REG,
+		.hw.init	= &osc32k_fanout_init_data,
+	},
+};
+
+static struct ccu_common *sun6i_rtc_ccu_clks[] = {
+	&iosc_clk,
+	&iosc_32k_clk,
+	&ext_osc32k_gate_clk.common,
+	&osc32k_clk.common,
+	&osc24M_32k_clk.common,
+	&rtc_32k_clk.common,
+	&osc32k_fanout_clk.common,
+};
+
+static struct clk_hw_onecell_data sun6i_rtc_ccu_hw_clks = {
+	.num = CLK_NUMBER,
+	.hws = {
+		[CLK_OSC32K]		= &osc32k_clk.common.hw,
+		[CLK_OSC32K_FANOUT]	= &osc32k_fanout_clk.common.hw,
+		[CLK_IOSC]		= &iosc_clk.hw,
+		[CLK_IOSC_32K]		= &iosc_32k_clk.hw,
+		[CLK_EXT_OSC32K_GATE]	= &ext_osc32k_gate_clk.common.hw,
+		[CLK_OSC24M_32K]	= &osc24M_32k_clk.common.hw,
+		[CLK_RTC_32K]		= &rtc_32k_clk.common.hw,
+	},
+};
+
+static const struct sunxi_ccu_desc sun6i_rtc_ccu_desc = {
+	.ccu_clks	= sun6i_rtc_ccu_clks,
+	.num_ccu_clks	= ARRAY_SIZE(sun6i_rtc_ccu_clks),
+
+	.hw_clks	= &sun6i_rtc_ccu_hw_clks,
+};
+
+static const struct clk_parent_data sun50i_h616_osc32k_fanout_parents[] = {
+	{ .hw = &osc32k_clk.common.hw },
+	{ .fw_name = "pll-32k" },
+	{ .hw = &osc24M_32k_clk.common.hw }
+};
+
+static const struct clk_parent_data sun50i_r329_osc32k_fanout_parents[] = {
+	{ .hw = &osc32k_clk.common.hw },
+	{ .hw = &ext_osc32k_gate_clk.common.hw },
+	{ .hw = &osc24M_32k_clk.common.hw }
+};
+
+static const struct sun6i_rtc_match_data sun50i_h616_rtc_ccu_data = {
+	.have_iosc_calibration	= true,
+	.rtc_32k_single_parent	= true,
+	.osc32k_fanout_parents	= sun50i_h616_osc32k_fanout_parents,
+	.osc32k_fanout_nparents	= ARRAY_SIZE(sun50i_h616_osc32k_fanout_parents),
+};
+
+static const struct sun6i_rtc_match_data sun50i_r329_rtc_ccu_data = {
+	.have_ext_osc32k	= true,
+	.osc32k_fanout_parents	= sun50i_r329_osc32k_fanout_parents,
+	.osc32k_fanout_nparents	= ARRAY_SIZE(sun50i_r329_osc32k_fanout_parents),
+};
+
+static const struct of_device_id sun6i_rtc_ccu_match[] = {
+	{
+		.compatible	= "allwinner,sun50i-h616-rtc",
+		.data		= &sun50i_h616_rtc_ccu_data,
+	},
+	{
+		.compatible	= "allwinner,sun50i-r329-rtc",
+		.data		= &sun50i_r329_rtc_ccu_data,
+	},
+	{},
+};
+
+int sun6i_rtc_ccu_probe(struct device *dev, void __iomem *reg)
+{
+	const struct sun6i_rtc_match_data *data;
+	struct clk *ext_osc32k_clk = NULL;
+	const struct of_device_id *match;
+
+	/* This driver is only used for newer variants of the hardware. */
+	match = of_match_device(sun6i_rtc_ccu_match, dev);
+	if (!match)
+		return 0;
+
+	data = match->data;
+	have_iosc_calibration = data->have_iosc_calibration;
+
+	if (data->have_ext_osc32k) {
+		const char *fw_name;
+
+		/* ext-osc32k was the only input clock in the old binding. */
+		fw_name = of_property_read_bool(dev->of_node, "clock-names")
+			? "ext-osc32k" : NULL;
+		ext_osc32k_clk = devm_clk_get_optional(dev, fw_name);
+		if (IS_ERR(ext_osc32k_clk))
+			return PTR_ERR(ext_osc32k_clk);
+	}
+
+	if (ext_osc32k_clk) {
+		/* Link ext-osc32k-gate to its parent. */
+		*ext_osc32k = __clk_get_hw(ext_osc32k_clk);
+	} else {
+		/* ext-osc32k-gate is an orphan, so do not register it. */
+		sun6i_rtc_ccu_hw_clks.hws[CLK_EXT_OSC32K_GATE] = NULL;
+		osc32k_init_data.num_parents = 1;
+	}
+
+	if (data->rtc_32k_single_parent)
+		rtc_32k_init_data.num_parents = 1;
+
+	osc32k_fanout_init_data.parent_data = data->osc32k_fanout_parents;
+	osc32k_fanout_init_data.num_parents = data->osc32k_fanout_nparents;
+
+	return devm_sunxi_ccu_probe(dev, reg, &sun6i_rtc_ccu_desc);
+}
+
+MODULE_IMPORT_NS(SUNXI_CCU);
+MODULE_LICENSE("GPL");