diff options
Diffstat (limited to 'drivers/clk/clk-twl.c')
| -rw-r--r-- | drivers/clk/clk-twl.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/drivers/clk/clk-twl.c b/drivers/clk/clk-twl.c new file mode 100644 index 000000000000..eab9d3c8ed8a --- /dev/null +++ b/drivers/clk/clk-twl.c @@ -0,0 +1,197 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Clock driver for twl device. + * + * inspired by the driver for the Palmas device + */ + +#include <linux/clk-provider.h> +#include <linux/mfd/twl.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#define VREG_STATE 2 +#define TWL6030_CFG_STATE_OFF 0x00 +#define TWL6030_CFG_STATE_ON 0x01 +#define TWL6030_CFG_STATE_MASK 0x03 + +struct twl_clock_info { + struct device *dev; + u8 base; + struct clk_hw hw; +}; + +static inline int +twlclk_read(struct twl_clock_info *info, unsigned int slave_subgp, + unsigned int offset) +{ + u8 value; + int status; + + status = twl_i2c_read_u8(slave_subgp, &value, + info->base + offset); + return (status < 0) ? status : value; +} + +static inline int +twlclk_write(struct twl_clock_info *info, unsigned int slave_subgp, + unsigned int offset, u8 value) +{ + return twl_i2c_write_u8(slave_subgp, value, + info->base + offset); +} + +static inline struct twl_clock_info *to_twl_clks_info(struct clk_hw *hw) +{ + return container_of(hw, struct twl_clock_info, hw); +} + +static unsigned long twl_clks_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + return 32768; +} + +static int twl6032_clks_prepare(struct clk_hw *hw) +{ + struct twl_clock_info *cinfo = to_twl_clks_info(hw); + int ret; + + ret = twlclk_write(cinfo, TWL_MODULE_PM_RECEIVER, VREG_STATE, + TWL6030_CFG_STATE_ON); + if (ret < 0) + dev_err(cinfo->dev, "clk prepare failed\n"); + + return ret; +} + +static void twl6032_clks_unprepare(struct clk_hw *hw) +{ + struct twl_clock_info *cinfo = to_twl_clks_info(hw); + int ret; + + ret = twlclk_write(cinfo, TWL_MODULE_PM_RECEIVER, VREG_STATE, + TWL6030_CFG_STATE_OFF); + if (ret < 0) + dev_err(cinfo->dev, "clk unprepare failed\n"); +} + +static int twl6032_clks_is_prepared(struct clk_hw *hw) +{ + struct twl_clock_info *cinfo = to_twl_clks_info(hw); + int val; + + val = twlclk_read(cinfo, TWL_MODULE_PM_RECEIVER, VREG_STATE); + if (val < 0) { + dev_err(cinfo->dev, "clk read failed\n"); + return val; + } + + val &= TWL6030_CFG_STATE_MASK; + + return val == TWL6030_CFG_STATE_ON; +} + +static const struct clk_ops twl6032_clks_ops = { + .prepare = twl6032_clks_prepare, + .unprepare = twl6032_clks_unprepare, + .is_prepared = twl6032_clks_is_prepared, + .recalc_rate = twl_clks_recalc_rate, +}; + +struct twl_clks_data { + struct clk_init_data init; + u8 base; +}; + +static const struct twl_clks_data twl6032_clks[] = { + { + .init = { + .name = "clk32kg", + .ops = &twl6032_clks_ops, + .flags = CLK_IGNORE_UNUSED, + }, + .base = 0x8C, + }, + { + .init = { + .name = "clk32kaudio", + .ops = &twl6032_clks_ops, + .flags = CLK_IGNORE_UNUSED, + }, + .base = 0x8F, + }, + { + /* sentinel */ + } +}; + +static int twl_clks_probe(struct platform_device *pdev) +{ + struct clk_hw_onecell_data *clk_data; + const struct twl_clks_data *hw_data; + + struct twl_clock_info *cinfo; + int ret; + int i; + int count; + + hw_data = twl6032_clks; + for (count = 0; hw_data[count].init.name; count++) + ; + + clk_data = devm_kzalloc(&pdev->dev, + struct_size(clk_data, hws, count), + GFP_KERNEL); + if (!clk_data) + return -ENOMEM; + + clk_data->num = count; + cinfo = devm_kcalloc(&pdev->dev, count, sizeof(*cinfo), GFP_KERNEL); + if (!cinfo) + return -ENOMEM; + + for (i = 0; i < count; i++) { + cinfo[i].base = hw_data[i].base; + cinfo[i].dev = &pdev->dev; + cinfo[i].hw.init = &hw_data[i].init; + ret = devm_clk_hw_register(&pdev->dev, &cinfo[i].hw); + if (ret) { + return dev_err_probe(&pdev->dev, ret, + "Fail to register clock %s\n", + hw_data[i].init.name); + } + clk_data->hws[i] = &cinfo[i].hw; + } + + ret = devm_of_clk_add_hw_provider(&pdev->dev, + of_clk_hw_onecell_get, clk_data); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, + "Fail to add clock driver\n"); + + return 0; +} + +static const struct platform_device_id twl_clks_id[] = { + { + .name = "twl6032-clk", + }, { + /* sentinel */ + } +}; +MODULE_DEVICE_TABLE(platform, twl_clks_id); + +static struct platform_driver twl_clks_driver = { + .driver = { + .name = "twl-clk", + }, + .probe = twl_clks_probe, + .id_table = twl_clks_id, +}; + +module_platform_driver(twl_clks_driver); + +MODULE_DESCRIPTION("Clock driver for TWL Series Devices"); +MODULE_LICENSE("GPL"); |