diff options
Diffstat (limited to 'drivers/clk/clk-palmas.c')
| -rw-r--r-- | drivers/clk/clk-palmas.c | 307 |
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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