clk: mediatek: Add USB clock support in MT8173 APMIXEDSYS

Add REF2USB_TX clock support into MT8173 APMIXEDSYS. This clock
is needed by USB 3.0.

Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>

1 files changed, 107 insertions, 0 deletions

diff --git a/drivers/clk/mediatek/clk-apmixed.c b/drivers/clk/mediatek/clk-apmixed.c
new file mode 100644
index 000000000000..5303c5980867
--- /dev/null
+++ b/drivers/clk/mediatek/clk-apmixed.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author: James Liao <jamesjj.liao@mediatek.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+#include "clk-mtk.h"
+
+#define REF2USB_TX_EN		BIT(0)
+#define REF2USB_TX_LPF_EN	BIT(1)
+#define REF2USB_TX_OUT_EN	BIT(2)
+#define REF2USB_EN_MASK		(REF2USB_TX_EN | REF2USB_TX_LPF_EN | \
+				 REF2USB_TX_OUT_EN)
+
+struct mtk_ref2usb_tx {
+	struct clk_hw	hw;
+	void __iomem	*base_addr;
+};
+
+static inline struct mtk_ref2usb_tx *to_mtk_ref2usb_tx(struct clk_hw *hw)
+{
+	return container_of(hw, struct mtk_ref2usb_tx, hw);
+}
+
+static int mtk_ref2usb_tx_is_prepared(struct clk_hw *hw)
+{
+	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
+
+	return (readl(tx->base_addr) & REF2USB_EN_MASK) == REF2USB_EN_MASK;
+}
+
+static int mtk_ref2usb_tx_prepare(struct clk_hw *hw)
+{
+	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
+	u32 val;
+
+	val = readl(tx->base_addr);
+
+	val |= REF2USB_TX_EN;
+	writel(val, tx->base_addr);
+	udelay(100);
+
+	val |= REF2USB_TX_LPF_EN;
+	writel(val, tx->base_addr);
+
+	val |= REF2USB_TX_OUT_EN;
+	writel(val, tx->base_addr);
+
+	return 0;
+}
+
+static void mtk_ref2usb_tx_unprepare(struct clk_hw *hw)
+{
+	struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
+	u32 val;
+
+	val = readl(tx->base_addr);
+	val &= ~REF2USB_EN_MASK;
+	writel(val, tx->base_addr);
+}
+
+static const struct clk_ops mtk_ref2usb_tx_ops = {
+	.is_prepared	= mtk_ref2usb_tx_is_prepared,
+	.prepare	= mtk_ref2usb_tx_prepare,
+	.unprepare	= mtk_ref2usb_tx_unprepare,
+};
+
+struct clk * __init mtk_clk_register_ref2usb_tx(const char *name,
+			const char *parent_name, void __iomem *reg)
+{
+	struct mtk_ref2usb_tx *tx;
+	struct clk_init_data init = {};
+	struct clk *clk;
+
+	tx = kzalloc(sizeof(*tx), GFP_KERNEL);
+	if (!tx)
+		return ERR_PTR(-ENOMEM);
+
+	tx->base_addr = reg;
+	tx->hw.init = &init;
+
+	init.name = name;
+	init.ops = &mtk_ref2usb_tx_ops;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+
+	clk = clk_register(NULL, &tx->hw);
+
+	if (IS_ERR(clk)) {
+		pr_err("Failed to register clk %s: %ld\n", name, PTR_ERR(clk));
+		kfree(tx);
+	}
+
+	return clk;
+}