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path: root/drivers/clk/clk-palmas.c
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-rw-r--r--drivers/clk/clk-palmas.c307
1 files changed, 307 insertions, 0 deletions
diff --git a/drivers/clk/clk-palmas.c b/drivers/clk/clk-palmas.c
new file mode 100644
index 000000000000..781630e1372b
--- /dev/null
+++ b/drivers/clk/clk-palmas.c
@@ -0,0 +1,307 @@
+/*
+ * Clock driver for Palmas device.
+ *
+ * Copyright (c) 2013, NVIDIA Corporation.
+ * Copyright (c) 2013-2014 Texas Instruments, Inc.
+ *
+ * Author: Laxman Dewangan <ldewangan@nvidia.com>
+ * Peter Ujfalusi <peter.ujfalusi@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
+ * whether express or implied; 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/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/mfd/palmas.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1 1
+#define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2 2
+#define PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP 3
+
+struct palmas_clk32k_desc {
+ const char *clk_name;
+ unsigned int control_reg;
+ unsigned int enable_mask;
+ unsigned int sleep_mask;
+ unsigned int sleep_reqstr_id;
+ int delay;
+};
+
+struct palmas_clock_info {
+ struct device *dev;
+ struct clk *clk;
+ struct clk_hw hw;
+ struct palmas *palmas;
+ struct palmas_clk32k_desc *clk_desc;
+ int ext_control_pin;
+};
+
+static inline struct palmas_clock_info *to_palmas_clks_info(struct clk_hw *hw)
+{
+ return container_of(hw, struct palmas_clock_info, hw);
+}
+
+static unsigned long palmas_clks_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ return 32768;
+}
+
+static int palmas_clks_prepare(struct clk_hw *hw)
+{
+ struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
+ int ret;
+
+ ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg,
+ cinfo->clk_desc->enable_mask,
+ cinfo->clk_desc->enable_mask);
+ if (ret < 0)
+ dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+ else if (cinfo->clk_desc->delay)
+ udelay(cinfo->clk_desc->delay);
+
+ return ret;
+}
+
+static void palmas_clks_unprepare(struct clk_hw *hw)
+{
+ struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
+ int ret;
+
+ /*
+ * Clock can be disabled through external pin if it is externally
+ * controlled.
+ */
+ if (cinfo->ext_control_pin)
+ return;
+
+ ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg,
+ cinfo->clk_desc->enable_mask, 0);
+ if (ret < 0)
+ dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+}
+
+static int palmas_clks_is_prepared(struct clk_hw *hw)
+{
+ struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
+ int ret;
+ u32 val;
+
+ if (cinfo->ext_control_pin)
+ return 1;
+
+ ret = palmas_read(cinfo->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg, &val);
+ if (ret < 0) {
+ dev_err(cinfo->dev, "Reg 0x%02x read failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+ return ret;
+ }
+ return !!(val & cinfo->clk_desc->enable_mask);
+}
+
+static struct clk_ops palmas_clks_ops = {
+ .prepare = palmas_clks_prepare,
+ .unprepare = palmas_clks_unprepare,
+ .is_prepared = palmas_clks_is_prepared,
+ .recalc_rate = palmas_clks_recalc_rate,
+};
+
+struct palmas_clks_of_match_data {
+ struct clk_init_data init;
+ struct palmas_clk32k_desc desc;
+};
+
+static struct palmas_clks_of_match_data palmas_of_clk32kg = {
+ .init = {
+ .name = "clk32kg",
+ .ops = &palmas_clks_ops,
+ .flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
+ },
+ .desc = {
+ .clk_name = "clk32kg",
+ .control_reg = PALMAS_CLK32KG_CTRL,
+ .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
+ .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
+ .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KG,
+ .delay = 200,
+ },
+};
+
+static struct palmas_clks_of_match_data palmas_of_clk32kgaudio = {
+ .init = {
+ .name = "clk32kgaudio",
+ .ops = &palmas_clks_ops,
+ .flags = CLK_IS_ROOT | CLK_IGNORE_UNUSED,
+ },
+ .desc = {
+ .clk_name = "clk32kgaudio",
+ .control_reg = PALMAS_CLK32KGAUDIO_CTRL,
+ .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
+ .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
+ .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KGAUDIO,
+ .delay = 200,
+ },
+};
+
+static struct of_device_id palmas_clks_of_match[] = {
+ {
+ .compatible = "ti,palmas-clk32kg",
+ .data = &palmas_of_clk32kg,
+ },
+ {
+ .compatible = "ti,palmas-clk32kgaudio",
+ .data = &palmas_of_clk32kgaudio,
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, palmas_clks_of_match);
+
+static void palmas_clks_get_clk_data(struct platform_device *pdev,
+ struct palmas_clock_info *cinfo)
+{
+ struct device_node *node = pdev->dev.of_node;
+ unsigned int prop;
+ int ret;
+
+ ret = of_property_read_u32(node, "ti,external-sleep-control",
+ &prop);
+ if (ret)
+ return;
+
+ switch (prop) {
+ case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1:
+ prop = PALMAS_EXT_CONTROL_ENABLE1;
+ break;
+ case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2:
+ prop = PALMAS_EXT_CONTROL_ENABLE2;
+ break;
+ case PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP:
+ prop = PALMAS_EXT_CONTROL_NSLEEP;
+ break;
+ default:
+ dev_warn(&pdev->dev, "%s: Invalid ext control option: %u\n",
+ node->name, prop);
+ prop = 0;
+ break;
+ }
+ cinfo->ext_control_pin = prop;
+}
+
+static int palmas_clks_init_configure(struct palmas_clock_info *cinfo)
+{
+ int ret;
+
+ ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
+ cinfo->clk_desc->control_reg,
+ cinfo->clk_desc->sleep_mask, 0);
+ if (ret < 0) {
+ dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
+ cinfo->clk_desc->control_reg, ret);
+ return ret;
+ }
+
+ if (cinfo->ext_control_pin) {
+ ret = clk_prepare(cinfo->clk);
+ if (ret < 0) {
+ dev_err(cinfo->dev, "Clock prep failed, %d\n", ret);
+ return ret;
+ }
+
+ ret = palmas_ext_control_req_config(cinfo->palmas,
+ cinfo->clk_desc->sleep_reqstr_id,
+ cinfo->ext_control_pin, true);
+ if (ret < 0) {
+ dev_err(cinfo->dev, "Ext config for %s failed, %d\n",
+ cinfo->clk_desc->clk_name, ret);
+ return ret;
+ }
+ }
+
+ return ret;
+}
+static int palmas_clks_probe(struct platform_device *pdev)
+{
+ struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
+ struct device_node *node = pdev->dev.of_node;
+ struct palmas_clks_of_match_data *match_data;
+ const struct of_device_id *match;
+ struct palmas_clock_info *cinfo;
+ struct clk *clk;
+ int ret;
+
+ match = of_match_device(palmas_clks_of_match, &pdev->dev);
+ match_data = (struct palmas_clks_of_match_data *)match->data;
+
+ cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
+ if (!cinfo)
+ return -ENOMEM;
+
+ palmas_clks_get_clk_data(pdev, cinfo);
+ platform_set_drvdata(pdev, cinfo);
+
+ cinfo->dev = &pdev->dev;
+ cinfo->palmas = palmas;
+
+ cinfo->clk_desc = &match_data->desc;
+ cinfo->hw.init = &match_data->init;
+ clk = devm_clk_register(&pdev->dev, &cinfo->hw);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ dev_err(&pdev->dev, "Fail to register clock %s, %d\n",
+ match_data->desc.clk_name, ret);
+ return ret;
+ }
+
+ cinfo->clk = clk;
+ ret = palmas_clks_init_configure(cinfo);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Clock config failed, %d\n", ret);
+ return ret;
+ }
+
+ ret = of_clk_add_provider(node, of_clk_src_simple_get, cinfo->clk);
+ if (ret < 0)
+ dev_err(&pdev->dev, "Fail to add clock driver, %d\n", ret);
+ return ret;
+}
+
+static int palmas_clks_remove(struct platform_device *pdev)
+{
+ of_clk_del_provider(pdev->dev.of_node);
+ return 0;
+}
+
+static struct platform_driver palmas_clks_driver = {
+ .driver = {
+ .name = "palmas-clk",
+ .owner = THIS_MODULE,
+ .of_match_table = palmas_clks_of_match,
+ },
+ .probe = palmas_clks_probe,
+ .remove = palmas_clks_remove,
+};
+
+module_platform_driver(palmas_clks_driver);
+
+MODULE_DESCRIPTION("Clock driver for Palmas Series Devices");
+MODULE_ALIAS("platform:palmas-clk");
+MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
+MODULE_LICENSE("GPL v2");
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