Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 193 insertions, 0 deletions

diff --git a/drivers/clk/meson/gxbb-aoclk-32k.c b/drivers/clk/meson/gxbb-aoclk-32k.c
new file mode 100644
index 000000000..680467141
--- /dev/null
+++ b/drivers/clk/meson/gxbb-aoclk-32k.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2017 BayLibre, SAS.
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/bitfield.h>
+#include <linux/regmap.h>
+#include "gxbb-aoclk.h"
+
+/*
+ * The AO Domain embeds a dual/divider to generate a more precise
+ * 32,768KHz clock for low-power suspend mode and CEC.
+ *                      ______   ______
+ *                     |      | |      |
+ *         ______      | Div1 |-| Cnt1 |       ______
+ *        |      |    /|______| |______|\     |      |
+ * Xtal-->| Gate |---|  ______   ______  X-X--| Gate |-->
+ *        |______| |  \|      | |      |/  |  |______|
+ *                 |   | Div2 |-| Cnt2 |   |
+ *                 |   |______| |______|   |
+ *                 |_______________________|
+ *
+ * The dividing can be switched to single or dual, with a counter
+ * for each divider to set when the switching is done.
+ * The entire dividing mechanism can be also bypassed.
+ */
+
+#define CLK_CNTL0_N1_MASK	GENMASK(11, 0)
+#define CLK_CNTL0_N2_MASK	GENMASK(23, 12)
+#define CLK_CNTL0_DUALDIV_EN	BIT(28)
+#define CLK_CNTL0_OUT_GATE_EN	BIT(30)
+#define CLK_CNTL0_IN_GATE_EN	BIT(31)
+
+#define CLK_CNTL1_M1_MASK	GENMASK(11, 0)
+#define CLK_CNTL1_M2_MASK	GENMASK(23, 12)
+#define CLK_CNTL1_BYPASS_EN	BIT(24)
+#define CLK_CNTL1_SELECT_OSC	BIT(27)
+
+#define PWR_CNTL_ALT_32K_SEL	GENMASK(13, 10)
+
+struct cec_32k_freq_table {
+	unsigned long parent_rate;
+	unsigned long target_rate;
+	bool dualdiv;
+	unsigned int n1;
+	unsigned int n2;
+	unsigned int m1;
+	unsigned int m2;
+};
+
+static const struct cec_32k_freq_table aoclk_cec_32k_table[] = {
+	[0] = {
+		.parent_rate = 24000000,
+		.target_rate = 32768,
+		.dualdiv = true,
+		.n1 = 733,
+		.n2 = 732,
+		.m1 = 8,
+		.m2 = 11,
+	},
+};
+
+/*
+ * If CLK_CNTL0_DUALDIV_EN == 0
+ *  - will use N1 divider only
+ * If CLK_CNTL0_DUALDIV_EN == 1
+ *  - hold M1 cycles of N1 divider then changes to N2
+ *  - hold M2 cycles of N2 divider then changes to N1
+ * Then we can get more accurate division.
+ */
+static unsigned long aoclk_cec_32k_recalc_rate(struct clk_hw *hw,
+					       unsigned long parent_rate)
+{
+	struct aoclk_cec_32k *cec_32k = to_aoclk_cec_32k(hw);
+	unsigned long n1;
+	u32 reg0, reg1;
+
+	regmap_read(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0, &reg0);
+	regmap_read(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL1, &reg1);
+
+	if (reg1 & CLK_CNTL1_BYPASS_EN)
+		return parent_rate;
+
+	if (reg0 & CLK_CNTL0_DUALDIV_EN) {
+		unsigned long n2, m1, m2, f1, f2, p1, p2;
+
+		n1 = FIELD_GET(CLK_CNTL0_N1_MASK, reg0) + 1;
+		n2 = FIELD_GET(CLK_CNTL0_N2_MASK, reg0) + 1;
+
+		m1 = FIELD_GET(CLK_CNTL1_M1_MASK, reg1) + 1;
+		m2 = FIELD_GET(CLK_CNTL1_M2_MASK, reg1) + 1;
+
+		f1 = DIV_ROUND_CLOSEST(parent_rate, n1);
+		f2 = DIV_ROUND_CLOSEST(parent_rate, n2);
+
+		p1 = DIV_ROUND_CLOSEST(100000000 * m1, f1 * (m1 + m2));
+		p2 = DIV_ROUND_CLOSEST(100000000 * m2, f2 * (m1 + m2));
+
+		return DIV_ROUND_UP(100000000, p1 + p2);
+	}
+
+	n1 = FIELD_GET(CLK_CNTL0_N1_MASK, reg0) + 1;
+
+	return DIV_ROUND_CLOSEST(parent_rate, n1);
+}
+
+static const struct cec_32k_freq_table *find_cec_32k_freq(unsigned long rate,
+							  unsigned long prate)
+{
+	int i;
+
+	for (i = 0 ; i < ARRAY_SIZE(aoclk_cec_32k_table) ; ++i)
+		if (aoclk_cec_32k_table[i].parent_rate == prate &&
+		    aoclk_cec_32k_table[i].target_rate == rate)
+			return &aoclk_cec_32k_table[i];
+
+	return NULL;
+}
+
+static long aoclk_cec_32k_round_rate(struct clk_hw *hw, unsigned long rate,
+				     unsigned long *prate)
+{
+	const struct cec_32k_freq_table *freq = find_cec_32k_freq(rate,
+								  *prate);
+
+	/* If invalid return first one */
+	if (!freq)
+		return aoclk_cec_32k_table[0].target_rate;
+
+	return freq->target_rate;
+}
+
+/*
+ * From the Amlogic init procedure, the IN and OUT gates needs to be handled
+ * in the init procedure to avoid any glitches.
+ */
+
+static int aoclk_cec_32k_set_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long parent_rate)
+{
+	const struct cec_32k_freq_table *freq = find_cec_32k_freq(rate,
+								  parent_rate);
+	struct aoclk_cec_32k *cec_32k = to_aoclk_cec_32k(hw);
+	u32 reg = 0;
+
+	if (!freq)
+		return -EINVAL;
+
+	/* Disable clock */
+	regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
+			   CLK_CNTL0_IN_GATE_EN | CLK_CNTL0_OUT_GATE_EN, 0);
+
+	reg = FIELD_PREP(CLK_CNTL0_N1_MASK, freq->n1 - 1);
+	if (freq->dualdiv)
+		reg |= CLK_CNTL0_DUALDIV_EN |
+		       FIELD_PREP(CLK_CNTL0_N2_MASK, freq->n2 - 1);
+
+	regmap_write(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0, reg);
+
+	reg = FIELD_PREP(CLK_CNTL1_M1_MASK, freq->m1 - 1);
+	if (freq->dualdiv)
+		reg |= FIELD_PREP(CLK_CNTL1_M2_MASK, freq->m2 - 1);
+
+	regmap_write(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL1, reg);
+
+	/* Enable clock */
+	regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
+			   CLK_CNTL0_IN_GATE_EN, CLK_CNTL0_IN_GATE_EN);
+
+	udelay(200);
+
+	regmap_update_bits(cec_32k->regmap, AO_RTC_ALT_CLK_CNTL0,
+			   CLK_CNTL0_OUT_GATE_EN, CLK_CNTL0_OUT_GATE_EN);
+
+	regmap_update_bits(cec_32k->regmap, AO_CRT_CLK_CNTL1,
+			   CLK_CNTL1_SELECT_OSC, CLK_CNTL1_SELECT_OSC);
+
+	/* Select 32k from XTAL */
+	regmap_update_bits(cec_32k->regmap,
+			  AO_RTI_PWR_CNTL_REG0,
+			  PWR_CNTL_ALT_32K_SEL,
+			  FIELD_PREP(PWR_CNTL_ALT_32K_SEL, 4));
+
+	return 0;
+}
+
+const struct clk_ops meson_aoclk_cec_32k_ops = {
+	.recalc_rate = aoclk_cec_32k_recalc_rate,
+	.round_rate = aoclk_cec_32k_round_rate,
+	.set_rate = aoclk_cec_32k_set_rate,
+};