clk: mvebu: new driver for Armada CP110 system controller

The Armada CP110 system controller provides, amongst other things, a
number of clocks for the platform: a small number of core clocks, and
then a number of gatable clocks, derived from some of the core
clocks. Those clocks are configured via registers of the CP110 System
Controller.

The CP110 is the other core HW block (next to the AP806) used in the
Marvel Armada 7K and 8K SoCs.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
[sboyd@codeaurora.org: Silence some checkpatch noise]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

1 files changed, 406 insertions, 0 deletions

diff --git a/drivers/clk/mvebu/cp110-system-controller.c b/drivers/clk/mvebu/cp110-system-controller.c
new file mode 100644
index 000000000000..7fa42d6b2b92
--- /dev/null
+++ b/drivers/clk/mvebu/cp110-system-controller.c
@@ -0,0 +1,406 @@
+/*
+ * Marvell Armada CP110 System Controller
+ *
+ * Copyright (C) 2016 Marvell
+ *
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+/*
+ * CP110 has 5 core clocks:
+ *
+ *  - APLL		(1 Ghz)
+ *    - PPv2 core	(1/3 APLL)
+ *    - EIP		(1/2 APLL)
+ *      - Core		(1/2 EIP)
+ *
+ *  - NAND clock, which is either:
+ *    - Equal to the core clock
+ *    - 2/5 APLL
+ *
+ * CP110 has 32 gatable clocks, for the various peripherals in the
+ * IP. They have fairly complicated parent/child relationships.
+ */
+
+#define pr_fmt(fmt) "cp110-system-controller: " fmt
+
+#include <linux/clk-provider.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define CP110_PM_CLOCK_GATING_REG	0x220
+#define CP110_NAND_FLASH_CLK_CTRL_REG	0x700
+#define    NF_CLOCK_SEL_400_MASK	BIT(0)
+
+enum {
+	CP110_CLK_TYPE_CORE,
+	CP110_CLK_TYPE_GATABLE,
+};
+
+#define CP110_MAX_CORE_CLOCKS		5
+#define CP110_MAX_GATABLE_CLOCKS	32
+
+#define CP110_CLK_NUM \
+	(CP110_MAX_CORE_CLOCKS + CP110_MAX_GATABLE_CLOCKS)
+
+#define CP110_CORE_APLL			0
+#define CP110_CORE_PPV2			1
+#define CP110_CORE_EIP			2
+#define CP110_CORE_CORE			3
+#define CP110_CORE_NAND			4
+
+/* A number of gatable clocks need special handling */
+#define CP110_GATE_AUDIO		0
+#define CP110_GATE_COMM_UNIT		1
+#define CP110_GATE_NAND			2
+#define CP110_GATE_PPV2			3
+#define CP110_GATE_SDIO			4
+#define CP110_GATE_XOR1			7
+#define CP110_GATE_XOR0			8
+#define CP110_GATE_PCIE_X1_0		11
+#define CP110_GATE_PCIE_X1_1		12
+#define CP110_GATE_PCIE_X4		13
+#define CP110_GATE_PCIE_XOR		14
+#define CP110_GATE_SATA			15
+#define CP110_GATE_SATA_USB		16
+#define CP110_GATE_MAIN			17
+#define CP110_GATE_SDMMC		18
+#define CP110_GATE_SLOW_IO		21
+#define CP110_GATE_USB3H0		22
+#define CP110_GATE_USB3H1		23
+#define CP110_GATE_USB3DEV		24
+#define CP110_GATE_EIP150		25
+#define CP110_GATE_EIP197		26
+
+static struct clk *cp110_clks[CP110_CLK_NUM];
+
+static struct clk_onecell_data cp110_clk_data = {
+	.clks = cp110_clks,
+	.clk_num = CP110_CLK_NUM,
+};
+
+struct cp110_gate_clk {
+	struct clk_hw hw;
+	struct regmap *regmap;
+	u8 bit_idx;
+};
+
+#define to_cp110_gate_clk(clk) container_of(clk, struct cp110_gate_clk, hw)
+
+static int cp110_gate_enable(struct clk_hw *hw)
+{
+	struct cp110_gate_clk *gate = to_cp110_gate_clk(hw);
+
+	regmap_update_bits(gate->regmap, CP110_PM_CLOCK_GATING_REG,
+			   BIT(gate->bit_idx), BIT(gate->bit_idx));
+
+	return 0;
+}
+
+static void cp110_gate_disable(struct clk_hw *hw)
+{
+	struct cp110_gate_clk *gate = to_cp110_gate_clk(hw);
+
+	regmap_update_bits(gate->regmap, CP110_PM_CLOCK_GATING_REG,
+			   BIT(gate->bit_idx), 0);
+}
+
+static int cp110_gate_is_enabled(struct clk_hw *hw)
+{
+	struct cp110_gate_clk *gate = to_cp110_gate_clk(hw);
+	u32 val;
+
+	regmap_read(gate->regmap, CP110_PM_CLOCK_GATING_REG, &val);
+
+	return val & BIT(gate->bit_idx);
+}
+
+static const struct clk_ops cp110_gate_ops = {
+	.enable = cp110_gate_enable,
+	.disable = cp110_gate_disable,
+	.is_enabled = cp110_gate_is_enabled,
+};
+
+static struct clk *cp110_register_gate(const char *name,
+				       const char *parent_name,
+				       struct regmap *regmap, u8 bit_idx)
+{
+	struct cp110_gate_clk *gate;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
+	if (!gate)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &cp110_gate_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	gate->regmap = regmap;
+	gate->bit_idx = bit_idx;
+	gate->hw.init = &init;
+
+	clk = clk_register(NULL, &gate->hw);
+	if (IS_ERR(clk))
+		kfree(gate);
+
+	return clk;
+}
+
+static void cp110_unregister_gate(struct clk *clk)
+{
+	struct clk_hw *hw;
+
+	hw = __clk_get_hw(clk);
+	if (!hw)
+		return;
+
+	clk_unregister(clk);
+	kfree(to_cp110_gate_clk(hw));
+}
+
+static struct clk *cp110_of_clk_get(struct of_phandle_args *clkspec, void *data)
+{
+	struct clk_onecell_data *clk_data = data;
+	unsigned int type = clkspec->args[0];
+	unsigned int idx = clkspec->args[1];
+
+	if (type == CP110_CLK_TYPE_CORE) {
+		if (idx > CP110_MAX_CORE_CLOCKS)
+			return ERR_PTR(-EINVAL);
+		return clk_data->clks[idx];
+	} else if (type == CP110_CLK_TYPE_GATABLE) {
+		if (idx > CP110_MAX_GATABLE_CLOCKS)
+			return ERR_PTR(-EINVAL);
+		return clk_data->clks[CP110_MAX_CORE_CLOCKS + idx];
+	}
+
+	return ERR_PTR(-EINVAL);
+}
+
+static int cp110_syscon_clk_probe(struct platform_device *pdev)
+{
+	struct regmap *regmap;
+	struct device_node *np = pdev->dev.of_node;
+	const char *ppv2_name, *apll_name, *core_name, *eip_name, *nand_name;
+	struct clk *clk;
+	u32 nand_clk_ctrl;
+	int i, ret;
+
+	regmap = syscon_node_to_regmap(np);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	ret = regmap_read(regmap, CP110_NAND_FLASH_CLK_CTRL_REG,
+			  &nand_clk_ctrl);
+	if (ret)
+		return ret;
+
+	/* Register the APLL which is the root of the clk tree */
+	of_property_read_string_index(np, "core-clock-output-names",
+				      CP110_CORE_APLL, &apll_name);
+	clk = clk_register_fixed_rate(NULL, apll_name, NULL, 0,
+				      1000 * 1000 * 1000);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto fail0;
+	}
+
+	cp110_clks[CP110_CORE_APLL] = clk;
+
+	/* PPv2 is APLL/3 */
+	of_property_read_string_index(np, "core-clock-output-names",
+				      CP110_CORE_PPV2, &ppv2_name);
+	clk = clk_register_fixed_factor(NULL, ppv2_name, apll_name, 0, 1, 3);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto fail1;
+	}
+
+	cp110_clks[CP110_CORE_PPV2] = clk;
+
+	/* EIP clock is APLL/2 */
+	of_property_read_string_index(np, "core-clock-output-names",
+				      CP110_CORE_EIP, &eip_name);
+	clk = clk_register_fixed_factor(NULL, eip_name, apll_name, 0, 1, 2);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto fail2;
+	}
+
+	cp110_clks[CP110_CORE_EIP] = clk;
+
+	/* Core clock is EIP/2 */
+	of_property_read_string_index(np, "core-clock-output-names",
+				      CP110_CORE_CORE, &core_name);
+	clk = clk_register_fixed_factor(NULL, core_name, eip_name, 0, 1, 2);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto fail3;
+	}
+
+	cp110_clks[CP110_CORE_CORE] = clk;
+
+	/* NAND can be either APLL/2.5 or core clock */
+	of_property_read_string_index(np, "core-clock-output-names",
+				      CP110_CORE_NAND, &nand_name);
+	if (nand_clk_ctrl & NF_CLOCK_SEL_400_MASK)
+		clk = clk_register_fixed_factor(NULL, nand_name,
+						apll_name, 0, 2, 5);
+	else
+		clk = clk_register_fixed_factor(NULL, nand_name,
+						core_name, 0, 1, 1);
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto fail4;
+	}
+
+	cp110_clks[CP110_CORE_NAND] = clk;
+
+	for (i = 0; i < CP110_MAX_GATABLE_CLOCKS; i++) {
+		const char *parent, *name;
+		int ret;
+
+		ret = of_property_read_string_index(np,
+						    "gate-clock-output-names",
+						    i, &name);
+		/* Reached the end of the list? */
+		if (ret < 0)
+			break;
+
+		if (!strcmp(name, "none"))
+			continue;
+
+		switch (i) {
+		case CP110_GATE_AUDIO:
+		case CP110_GATE_COMM_UNIT:
+		case CP110_GATE_EIP150:
+		case CP110_GATE_EIP197:
+		case CP110_GATE_SLOW_IO:
+			of_property_read_string_index(np,
+						      "gate-clock-output-names",
+						      CP110_GATE_MAIN, &parent);
+			break;
+		case CP110_GATE_NAND:
+			parent = nand_name;
+			break;
+		case CP110_GATE_PPV2:
+			parent = ppv2_name;
+			break;
+		case CP110_GATE_SDIO:
+			of_property_read_string_index(np,
+						      "gate-clock-output-names",
+						      CP110_GATE_SDMMC, &parent);
+			break;
+		case CP110_GATE_XOR1:
+		case CP110_GATE_XOR0:
+		case CP110_GATE_PCIE_X1_0:
+		case CP110_GATE_PCIE_X1_1:
+		case CP110_GATE_PCIE_X4:
+			of_property_read_string_index(np,
+						      "gate-clock-output-names",
+						      CP110_GATE_PCIE_XOR, &parent);
+			break;
+		case CP110_GATE_SATA:
+		case CP110_GATE_USB3H0:
+		case CP110_GATE_USB3H1:
+		case CP110_GATE_USB3DEV:
+			of_property_read_string_index(np,
+						      "gate-clock-output-names",
+						      CP110_GATE_SATA_USB, &parent);
+			break;
+		default:
+			parent = core_name;
+			break;
+		}
+
+		clk = cp110_register_gate(name, parent, regmap, i);
+		if (IS_ERR(clk)) {
+			ret = PTR_ERR(clk);
+			goto fail_gate;
+		}
+
+		cp110_clks[CP110_MAX_CORE_CLOCKS + i] = clk;
+	}
+
+	ret = of_clk_add_provider(np, cp110_of_clk_get, &cp110_clk_data);
+	if (ret)
+		goto fail_clk_add;
+
+	return 0;
+
+fail_clk_add:
+fail_gate:
+	for (i = 0; i < CP110_MAX_GATABLE_CLOCKS; i++) {
+		clk = cp110_clks[CP110_MAX_CORE_CLOCKS + i];
+
+		if (clk)
+			cp110_unregister_gate(clk);
+	}
+
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_NAND]);
+fail4:
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_CORE]);
+fail3:
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_EIP]);
+fail2:
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_PPV2]);
+fail1:
+	clk_unregister_fixed_rate(cp110_clks[CP110_CORE_APLL]);
+fail0:
+	return ret;
+}
+
+static int cp110_syscon_clk_remove(struct platform_device *pdev)
+{
+	int i;
+
+	of_clk_del_provider(pdev->dev.of_node);
+
+	for (i = 0; i < CP110_MAX_GATABLE_CLOCKS; i++) {
+		struct clk *clk = cp110_clks[CP110_MAX_CORE_CLOCKS + i];
+
+		if (clk)
+			cp110_unregister_gate(clk);
+	}
+
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_NAND]);
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_CORE]);
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_EIP]);
+	clk_unregister_fixed_factor(cp110_clks[CP110_CORE_PPV2]);
+	clk_unregister_fixed_rate(cp110_clks[CP110_CORE_APLL]);
+
+	return 0;
+}
+
+static const struct of_device_id cp110_syscon_of_match[] = {
+	{ .compatible = "marvell,cp110-system-controller0", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, armada8k_pcie_of_match);
+
+static struct platform_driver cp110_syscon_driver = {
+	.probe = cp110_syscon_clk_probe,
+	.remove = cp110_syscon_clk_remove,
+	.driver		= {
+		.name	= "marvell-cp110-system-controller0",
+		.of_match_table = cp110_syscon_of_match,
+	},
+};
+
+module_platform_driver(cp110_syscon_driver);
+
+MODULE_DESCRIPTION("Marvell CP110 System Controller 0 driver");
+MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>");
+MODULE_LICENSE("GPL");