diff options
Diffstat (limited to 'drivers/clk/clk-wm831x.c')
| -rw-r--r-- | drivers/clk/clk-wm831x.c | 428 |
1 files changed, 428 insertions, 0 deletions
diff --git a/drivers/clk/clk-wm831x.c b/drivers/clk/clk-wm831x.c new file mode 100644 index 000000000000..e7b7765e85f3 --- /dev/null +++ b/drivers/clk/clk-wm831x.c @@ -0,0 +1,428 @@ +/* + * WM831x clock control + * + * Copyright 2011-2 Wolfson Microelectronics PLC. + * + * Author: Mark Brown <broonie@opensource.wolfsonmicro.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; either version 2 of the License, or (at your + * option) any later version. + * + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/mfd/wm831x/core.h> + +struct wm831x_clk { + struct wm831x *wm831x; + struct clk_hw xtal_hw; + struct clk_hw fll_hw; + struct clk_hw clkout_hw; + struct clk *xtal; + struct clk *fll; + struct clk *clkout; + bool xtal_ena; +}; + +static int wm831x_xtal_is_enabled(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + xtal_hw); + + return clkdata->xtal_ena; +} + +static unsigned long wm831x_xtal_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + xtal_hw); + + if (clkdata->xtal_ena) + return 32768; + else + return 0; +} + +static const struct clk_ops wm831x_xtal_ops = { + .is_enabled = wm831x_xtal_is_enabled, + .recalc_rate = wm831x_xtal_recalc_rate, +}; + +static struct clk_init_data wm831x_xtal_init = { + .name = "xtal", + .ops = &wm831x_xtal_ops, + .flags = CLK_IS_ROOT, +}; + +static const unsigned long wm831x_fll_auto_rates[] = { + 2048000, + 11289600, + 12000000, + 12288000, + 19200000, + 22579600, + 24000000, + 24576000, +}; + +static int wm831x_fll_is_enabled(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + fll_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_1); + if (ret < 0) { + dev_err(wm831x->dev, "Unable to read FLL_CONTROL_1: %d\n", + ret); + return true; + } + + return (ret & WM831X_FLL_ENA) != 0; +} + +static int wm831x_fll_prepare(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + fll_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_2, + WM831X_FLL_ENA, WM831X_FLL_ENA); + if (ret != 0) + dev_crit(wm831x->dev, "Failed to enable FLL: %d\n", ret); + + usleep_range(2000, 2000); + + return ret; +} + +static void wm831x_fll_unprepare(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + fll_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_set_bits(wm831x, WM831X_FLL_CONTROL_2, WM831X_FLL_ENA, 0); + if (ret != 0) + dev_crit(wm831x->dev, "Failed to disaable FLL: %d\n", ret); +} + +static unsigned long wm831x_fll_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + fll_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2); + if (ret < 0) { + dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n", + ret); + return 0; + } + + if (ret & WM831X_FLL_AUTO) + return wm831x_fll_auto_rates[ret & WM831X_FLL_AUTO_FREQ_MASK]; + + dev_err(wm831x->dev, "FLL only supported in AUTO mode\n"); + + return 0; +} + +static long wm831x_fll_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *unused) +{ + int best = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++) + if (abs(wm831x_fll_auto_rates[i] - rate) < + abs(wm831x_fll_auto_rates[best] - rate)) + best = i; + + return wm831x_fll_auto_rates[best]; +} + +static int wm831x_fll_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + fll_hw); + struct wm831x *wm831x = clkdata->wm831x; + int i; + + for (i = 0; i < ARRAY_SIZE(wm831x_fll_auto_rates); i++) + if (wm831x_fll_auto_rates[i] == rate) + break; + if (i == ARRAY_SIZE(wm831x_fll_auto_rates)) + return -EINVAL; + + if (wm831x_fll_is_enabled(hw)) + return -EPERM; + + return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_2, + WM831X_FLL_AUTO_FREQ_MASK, i); +} + +static const char *wm831x_fll_parents[] = { + "xtal", + "clkin", +}; + +static u8 wm831x_fll_get_parent(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + fll_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + /* AUTO mode is always clocked from the crystal */ + ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2); + if (ret < 0) { + dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n", + ret); + return 0; + } + + if (ret & WM831X_FLL_AUTO) + return 0; + + ret = wm831x_reg_read(wm831x, WM831X_FLL_CONTROL_5); + if (ret < 0) { + dev_err(wm831x->dev, "Unable to read FLL_CONTROL_5: %d\n", + ret); + return 0; + } + + switch (ret & WM831X_FLL_CLK_SRC_MASK) { + case 0: + return 0; + case 1: + return 1; + default: + dev_err(wm831x->dev, "Unsupported FLL clock source %d\n", + ret & WM831X_FLL_CLK_SRC_MASK); + return 0; + } +} + +static const struct clk_ops wm831x_fll_ops = { + .is_enabled = wm831x_fll_is_enabled, + .prepare = wm831x_fll_prepare, + .unprepare = wm831x_fll_unprepare, + .round_rate = wm831x_fll_round_rate, + .recalc_rate = wm831x_fll_recalc_rate, + .set_rate = wm831x_fll_set_rate, + .get_parent = wm831x_fll_get_parent, +}; + +static struct clk_init_data wm831x_fll_init = { + .name = "fll", + .ops = &wm831x_fll_ops, + .parent_names = wm831x_fll_parents, + .num_parents = ARRAY_SIZE(wm831x_fll_parents), + .flags = CLK_SET_RATE_GATE, +}; + +static int wm831x_clkout_is_enabled(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + clkout_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1); + if (ret < 0) { + dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n", + ret); + return true; + } + + return (ret & WM831X_CLKOUT_ENA) != 0; +} + +static int wm831x_clkout_prepare(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + clkout_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_reg_unlock(wm831x); + if (ret != 0) { + dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret); + return ret; + } + + ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1, + WM831X_CLKOUT_ENA, WM831X_CLKOUT_ENA); + if (ret != 0) + dev_crit(wm831x->dev, "Failed to enable CLKOUT: %d\n", ret); + + wm831x_reg_lock(wm831x); + + return ret; +} + +static void wm831x_clkout_unprepare(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + clkout_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_reg_unlock(wm831x); + if (ret != 0) { + dev_crit(wm831x->dev, "Failed to lock registers: %d\n", ret); + return; + } + + ret = wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1, + WM831X_CLKOUT_ENA, 0); + if (ret != 0) + dev_crit(wm831x->dev, "Failed to disable CLKOUT: %d\n", ret); + + wm831x_reg_lock(wm831x); +} + +static const char *wm831x_clkout_parents[] = { + "xtal", + "fll", +}; + +static u8 wm831x_clkout_get_parent(struct clk_hw *hw) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + clkout_hw); + struct wm831x *wm831x = clkdata->wm831x; + int ret; + + ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_1); + if (ret < 0) { + dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_1: %d\n", + ret); + return 0; + } + + if (ret & WM831X_CLKOUT_SRC) + return 0; + else + return 1; +} + +static int wm831x_clkout_set_parent(struct clk_hw *hw, u8 parent) +{ + struct wm831x_clk *clkdata = container_of(hw, struct wm831x_clk, + clkout_hw); + struct wm831x *wm831x = clkdata->wm831x; + + return wm831x_set_bits(wm831x, WM831X_CLOCK_CONTROL_1, + WM831X_CLKOUT_SRC, + parent << WM831X_CLKOUT_SRC_SHIFT); +} + +static const struct clk_ops wm831x_clkout_ops = { + .is_enabled = wm831x_clkout_is_enabled, + .prepare = wm831x_clkout_prepare, + .unprepare = wm831x_clkout_unprepare, + .get_parent = wm831x_clkout_get_parent, + .set_parent = wm831x_clkout_set_parent, +}; + +static struct clk_init_data wm831x_clkout_init = { + .name = "clkout", + .ops = &wm831x_clkout_ops, + .parent_names = wm831x_clkout_parents, + .num_parents = ARRAY_SIZE(wm831x_clkout_parents), + .flags = CLK_SET_RATE_PARENT, +}; + +static __devinit int wm831x_clk_probe(struct platform_device *pdev) +{ + struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); + struct wm831x_clk *clkdata; + int ret; + + clkdata = devm_kzalloc(&pdev->dev, sizeof(*clkdata), GFP_KERNEL); + if (!clkdata) + return -ENOMEM; + + /* XTAL_ENA can only be set via OTP/InstantConfig so just read once */ + ret = wm831x_reg_read(wm831x, WM831X_CLOCK_CONTROL_2); + if (ret < 0) { + dev_err(wm831x->dev, "Unable to read CLOCK_CONTROL_2: %d\n", + ret); + return ret; + } + clkdata->xtal_ena = ret & WM831X_XTAL_ENA; + + clkdata->xtal_hw.init = &wm831x_xtal_init; + clkdata->xtal = clk_register(&pdev->dev, &clkdata->xtal_hw); + if (!clkdata->xtal) + return -EINVAL; + + clkdata->fll_hw.init = &wm831x_fll_init; + clkdata->fll = clk_register(&pdev->dev, &clkdata->fll_hw); + if (!clkdata->fll) { + ret = -EINVAL; + goto err_xtal; + } + + clkdata->clkout_hw.init = &wm831x_clkout_init; + clkdata->clkout = clk_register(&pdev->dev, &clkdata->clkout_hw); + if (!clkdata->clkout) { + ret = -EINVAL; + goto err_fll; + } + + dev_set_drvdata(&pdev->dev, clkdata); + + return 0; + +err_fll: + clk_unregister(clkdata->fll); +err_xtal: + clk_unregister(clkdata->xtal); + return ret; +} + +static int __devexit wm831x_clk_remove(struct platform_device *pdev) +{ + struct wm831x_clk *clkdata = dev_get_drvdata(&pdev->dev); + + clk_unregister(clkdata->clkout); + clk_unregister(clkdata->fll); + clk_unregister(clkdata->xtal); + + return 0; +} + +static struct platform_driver wm831x_clk_driver = { + .probe = wm831x_clk_probe, + .remove = __devexit_p(wm831x_clk_remove), + .driver = { + .name = "wm831x-clk", + .owner = THIS_MODULE, + }, +}; + +module_platform_driver(wm831x_clk_driver); + +/* Module information */ +MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); +MODULE_DESCRIPTION("WM831x clock driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:wm831x-clk"); |