diff options
Diffstat (limited to 'drivers/clk/clk-bd718x7.c')
| -rw-r--r-- | drivers/clk/clk-bd718x7.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/clk/clk-bd718x7.c b/drivers/clk/clk-bd718x7.c new file mode 100644 index 000000000..b52e8d6f6 --- /dev/null +++ b/drivers/clk/clk-bd718x7.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (C) 2018 ROHM Semiconductors + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/mfd/rohm-generic.h> +#include <linux/clk-provider.h> +#include <linux/clkdev.h> +#include <linux/regmap.h> + +/* clk control registers */ +/* BD70528 */ +#define BD70528_REG_OUT32K 0x2c +/* BD71828 */ +#define BD71828_REG_OUT32K 0x4B +/* BD71837 and BD71847 */ +#define BD718XX_REG_OUT32K 0x2E + +/* + * BD71837, BD71847, BD70528 and BD71828 all use bit [0] to clk output control + */ +#define CLK_OUT_EN_MASK BIT(0) + + +struct bd718xx_clk { + struct clk_hw hw; + u8 reg; + u8 mask; + struct platform_device *pdev; + struct rohm_regmap_dev *mfd; +}; + +static int bd71837_clk_set(struct bd718xx_clk *c, unsigned int status) +{ + return regmap_update_bits(c->mfd->regmap, c->reg, c->mask, status); +} + +static void bd71837_clk_disable(struct clk_hw *hw) +{ + int rv; + struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw); + + rv = bd71837_clk_set(c, 0); + if (rv) + dev_dbg(&c->pdev->dev, "Failed to disable 32K clk (%d)\n", rv); +} + +static int bd71837_clk_enable(struct clk_hw *hw) +{ + struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw); + + return bd71837_clk_set(c, 0xffffffff); +} + +static int bd71837_clk_is_enabled(struct clk_hw *hw) +{ + int enabled; + int rval; + struct bd718xx_clk *c = container_of(hw, struct bd718xx_clk, hw); + + rval = regmap_read(c->mfd->regmap, c->reg, &enabled); + + if (rval) + return rval; + + return enabled & c->mask; +} + +static const struct clk_ops bd71837_clk_ops = { + .prepare = &bd71837_clk_enable, + .unprepare = &bd71837_clk_disable, + .is_prepared = &bd71837_clk_is_enabled, +}; + +static int bd71837_clk_probe(struct platform_device *pdev) +{ + struct bd718xx_clk *c; + int rval = -ENOMEM; + const char *parent_clk; + struct device *parent = pdev->dev.parent; + struct rohm_regmap_dev *mfd = dev_get_drvdata(parent); + struct clk_init_data init = { + .name = "bd718xx-32k-out", + .ops = &bd71837_clk_ops, + }; + enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data; + + c = devm_kzalloc(&pdev->dev, sizeof(*c), GFP_KERNEL); + if (!c) + return -ENOMEM; + + init.num_parents = 1; + parent_clk = of_clk_get_parent_name(parent->of_node, 0); + + init.parent_names = &parent_clk; + if (!parent_clk) { + dev_err(&pdev->dev, "No parent clk found\n"); + return -EINVAL; + } + switch (chip) { + case ROHM_CHIP_TYPE_BD71837: + case ROHM_CHIP_TYPE_BD71847: + c->reg = BD718XX_REG_OUT32K; + c->mask = CLK_OUT_EN_MASK; + break; + case ROHM_CHIP_TYPE_BD71828: + c->reg = BD71828_REG_OUT32K; + c->mask = CLK_OUT_EN_MASK; + break; + case ROHM_CHIP_TYPE_BD70528: + c->reg = BD70528_REG_OUT32K; + c->mask = CLK_OUT_EN_MASK; + break; + default: + dev_err(&pdev->dev, "Unknown clk chip\n"); + return -EINVAL; + } + c->mfd = mfd; + c->pdev = pdev; + c->hw.init = &init; + + of_property_read_string_index(parent->of_node, + "clock-output-names", 0, &init.name); + + rval = devm_clk_hw_register(&pdev->dev, &c->hw); + if (rval) { + dev_err(&pdev->dev, "failed to register 32K clk"); + return rval; + } + rval = devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get, + &c->hw); + if (rval) + dev_err(&pdev->dev, "adding clk provider failed\n"); + + return rval; +} + +static const struct platform_device_id bd718x7_clk_id[] = { + { "bd71837-clk", ROHM_CHIP_TYPE_BD71837 }, + { "bd71847-clk", ROHM_CHIP_TYPE_BD71847 }, + { "bd70528-clk", ROHM_CHIP_TYPE_BD70528 }, + { "bd71828-clk", ROHM_CHIP_TYPE_BD71828 }, + { }, +}; +MODULE_DEVICE_TABLE(platform, bd718x7_clk_id); + +static struct platform_driver bd71837_clk = { + .driver = { + .name = "bd718xx-clk", + }, + .probe = bd71837_clk_probe, + .id_table = bd718x7_clk_id, +}; + +module_platform_driver(bd71837_clk); + +MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>"); +MODULE_DESCRIPTION("BD71837/BD71847/BD70528 chip clk driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:bd718xx-clk"); |