clk: RK808: add clkout driver for RK808

This is the initial version of the RK808 PMIC.  This is a power management
IC for multimedia products.  It provides regulators that are able to
supply power to processor cores and other components.  The chip provides
other modules including RTC, Clockout.

Signed-off-by: Chris Zhong <zyw@rock-chips.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Doug Anderson <dianders@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Samuel Ortiz <sameo@linux.intel.com> says:
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Kever Yang <kever.yang@rock-chips.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 170 insertions, 0 deletions

diff --git a/drivers/clk/clk-rk808.c b/drivers/clk/clk-rk808.c
new file mode 100644
index 000000000000..83902b9cd49e
--- /dev/null
+++ b/drivers/clk/clk-rk808.c
@@ -0,0 +1,170 @@
+/*
+ * Clkout driver for Rockchip RK808
+ *
+ * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * Author:Chris Zhong <zyw@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/rk808.h>
+#include <linux/i2c.h>
+
+#define RK808_NR_OUTPUT 2
+
+struct rk808_clkout {
+        struct rk808 *rk808;
+        struct clk_onecell_data clk_data;
+        struct clk_hw           clkout1_hw;
+        struct clk_hw           clkout2_hw;
+};
+
+static unsigned long rk808_clkout_recalc_rate(struct clk_hw *hw,
+                                              unsigned long parent_rate)
+{
+        return 32768;
+}
+
+static int rk808_clkout2_enable(struct clk_hw *hw, bool enable)
+{
+        struct rk808_clkout *rk808_clkout = container_of(hw,
+                                                         struct rk808_clkout,
+                                                         clkout2_hw);
+        struct rk808 *rk808 = rk808_clkout->rk808;
+
+        return regmap_update_bits(rk808->regmap, RK808_CLK32OUT_REG,
+                                  CLK32KOUT2_EN, enable ? CLK32KOUT2_EN : 0);
+}
+
+static int rk808_clkout2_prepare(struct clk_hw *hw)
+{
+        return rk808_clkout2_enable(hw, true);
+}
+
+static void rk808_clkout2_unprepare(struct clk_hw *hw)
+{
+        rk808_clkout2_enable(hw, false);
+}
+
+static int rk808_clkout2_is_prepared(struct clk_hw *hw)
+{
+        struct rk808_clkout *rk808_clkout = container_of(hw,
+                                                         struct rk808_clkout,
+                                                         clkout2_hw);
+        struct rk808 *rk808 = rk808_clkout->rk808;
+        uint32_t val;
+
+        int ret = regmap_read(rk808->regmap, RK808_CLK32OUT_REG, &val);
+
+        if (ret < 0)
+                return ret;
+
+        return (val & CLK32KOUT2_EN) ? 1 : 0;
+}
+
+static const struct clk_ops rk808_clkout1_ops = {
+        .recalc_rate = rk808_clkout_recalc_rate,
+};
+
+static const struct clk_ops rk808_clkout2_ops = {
+        .prepare = rk808_clkout2_prepare,
+        .unprepare = rk808_clkout2_unprepare,
+        .is_prepared = rk808_clkout2_is_prepared,
+        .recalc_rate = rk808_clkout_recalc_rate,
+};
+
+static int rk808_clkout_probe(struct platform_device *pdev)
+{
+        struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
+        struct i2c_client *client = rk808->i2c;
+        struct device_node *node = client->dev.of_node;
+        struct clk_init_data init = {};
+        struct clk **clk_table;
+        struct rk808_clkout *rk808_clkout;
+
+        rk808_clkout = devm_kzalloc(&client->dev,
+                                    sizeof(*rk808_clkout), GFP_KERNEL);
+        if (!rk808_clkout)
+                return -ENOMEM;
+
+        rk808_clkout->rk808 = rk808;
+
+        clk_table = devm_kcalloc(&client->dev, RK808_NR_OUTPUT,
+                                 sizeof(struct clk *), GFP_KERNEL);
+        if (!clk_table)
+                return -ENOMEM;
+
+        init.flags = CLK_IS_ROOT;
+        init.parent_names = NULL;
+        init.num_parents = 0;
+        init.name = "rk808-clkout1";
+        init.ops = &rk808_clkout1_ops;
+        rk808_clkout->clkout1_hw.init = &init;
+
+        /* optional override of the clockname */
+        of_property_read_string_index(node, "clock-output-names",
+                                      0, &init.name);
+
+        clk_table[0] = devm_clk_register(&client->dev,
+                                         &rk808_clkout->clkout1_hw);
+        if (IS_ERR(clk_table[0]))
+                return PTR_ERR(clk_table[0]);
+
+        init.name = "rk808-clkout2";
+        init.ops = &rk808_clkout2_ops;
+        rk808_clkout->clkout2_hw.init = &init;
+
+        /* optional override of the clockname */
+        of_property_read_string_index(node, "clock-output-names",
+                                      1, &init.name);
+
+        clk_table[1] = devm_clk_register(&client->dev,
+                                         &rk808_clkout->clkout2_hw);
+        if (IS_ERR(clk_table[1]))
+                return PTR_ERR(clk_table[1]);
+
+        rk808_clkout->clk_data.clks = clk_table;
+        rk808_clkout->clk_data.clk_num = RK808_NR_OUTPUT;
+
+        return of_clk_add_provider(node, of_clk_src_onecell_get,
+                                   &rk808_clkout->clk_data);
+}
+
+static int rk808_clkout_remove(struct platform_device *pdev)
+{
+        struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
+        struct i2c_client *client = rk808->i2c;
+        struct device_node *node = client->dev.of_node;
+
+        of_clk_del_provider(node);
+
+        return 0;
+}
+
+static struct platform_driver rk808_clkout_driver = {
+        .probe = rk808_clkout_probe,
+        .remove = rk808_clkout_remove,
+        .driver         = {
+                .name   = "rk808-clkout",
+        },
+};
+
+module_platform_driver(rk808_clkout_driver);
+
+MODULE_DESCRIPTION("Clkout driver for the rk808 series PMICs");
+MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:rk808-clkout");