diff options
Diffstat (limited to 'drivers/clk/ti/autoidle.c')
| -rw-r--r-- | drivers/clk/ti/autoidle.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/drivers/clk/ti/autoidle.c b/drivers/clk/ti/autoidle.c new file mode 100644 index 0000000000..27e6b9cb18 --- /dev/null +++ b/drivers/clk/ti/autoidle.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TI clock autoidle support + * + * Copyright (C) 2013 Texas Instruments, Inc. + * + * Tero Kristo <t-kristo@ti.com> + */ + +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/clk/ti.h> + +#include "clock.h" + +struct clk_ti_autoidle { + struct clk_omap_reg reg; + u8 shift; + u8 flags; + const char *name; + struct list_head node; +}; + +#define AUTOIDLE_LOW 0x1 + +static LIST_HEAD(autoidle_clks); + +/* + * we have some non-atomic read/write + * operations behind it, so lets + * take one lock for handling autoidle + * of all clocks + */ +static DEFINE_SPINLOCK(autoidle_spinlock); + +static int _omap2_clk_deny_idle(struct clk_hw_omap *clk) +{ + if (clk->ops && clk->ops->deny_idle) { + unsigned long irqflags; + + spin_lock_irqsave(&autoidle_spinlock, irqflags); + clk->autoidle_count++; + if (clk->autoidle_count == 1) + clk->ops->deny_idle(clk); + + spin_unlock_irqrestore(&autoidle_spinlock, irqflags); + } + return 0; +} + +static int _omap2_clk_allow_idle(struct clk_hw_omap *clk) +{ + if (clk->ops && clk->ops->allow_idle) { + unsigned long irqflags; + + spin_lock_irqsave(&autoidle_spinlock, irqflags); + clk->autoidle_count--; + if (clk->autoidle_count == 0) + clk->ops->allow_idle(clk); + + spin_unlock_irqrestore(&autoidle_spinlock, irqflags); + } + return 0; +} + +/** + * omap2_clk_deny_idle - disable autoidle on an OMAP clock + * @clk: struct clk * to disable autoidle for + * + * Disable autoidle on an OMAP clock. + */ +int omap2_clk_deny_idle(struct clk *clk) +{ + struct clk_hw *hw; + + if (!clk) + return -EINVAL; + + hw = __clk_get_hw(clk); + + if (omap2_clk_is_hw_omap(hw)) { + struct clk_hw_omap *c = to_clk_hw_omap(hw); + + return _omap2_clk_deny_idle(c); + } + + return -EINVAL; +} + +/** + * omap2_clk_allow_idle - enable autoidle on an OMAP clock + * @clk: struct clk * to enable autoidle for + * + * Enable autoidle on an OMAP clock. + */ +int omap2_clk_allow_idle(struct clk *clk) +{ + struct clk_hw *hw; + + if (!clk) + return -EINVAL; + + hw = __clk_get_hw(clk); + + if (omap2_clk_is_hw_omap(hw)) { + struct clk_hw_omap *c = to_clk_hw_omap(hw); + + return _omap2_clk_allow_idle(c); + } + + return -EINVAL; +} + +static void _allow_autoidle(struct clk_ti_autoidle *clk) +{ + u32 val; + + val = ti_clk_ll_ops->clk_readl(&clk->reg); + + if (clk->flags & AUTOIDLE_LOW) + val &= ~(1 << clk->shift); + else + val |= (1 << clk->shift); + + ti_clk_ll_ops->clk_writel(val, &clk->reg); +} + +static void _deny_autoidle(struct clk_ti_autoidle *clk) +{ + u32 val; + + val = ti_clk_ll_ops->clk_readl(&clk->reg); + + if (clk->flags & AUTOIDLE_LOW) + val |= (1 << clk->shift); + else + val &= ~(1 << clk->shift); + + ti_clk_ll_ops->clk_writel(val, &clk->reg); +} + +/** + * _clk_generic_allow_autoidle_all - enable autoidle for all clocks + * + * Enables hardware autoidle for all registered DT clocks, which have + * the feature. + */ +static void _clk_generic_allow_autoidle_all(void) +{ + struct clk_ti_autoidle *c; + + list_for_each_entry(c, &autoidle_clks, node) + _allow_autoidle(c); +} + +/** + * _clk_generic_deny_autoidle_all - disable autoidle for all clocks + * + * Disables hardware autoidle for all registered DT clocks, which have + * the feature. + */ +static void _clk_generic_deny_autoidle_all(void) +{ + struct clk_ti_autoidle *c; + + list_for_each_entry(c, &autoidle_clks, node) + _deny_autoidle(c); +} + +/** + * of_ti_clk_autoidle_setup - sets up hardware autoidle for a clock + * @node: pointer to the clock device node + * + * Checks if a clock has hardware autoidle support or not (check + * for presence of 'ti,autoidle-shift' property in the device tree + * node) and sets up the hardware autoidle feature for the clock + * if available. If autoidle is available, the clock is also added + * to the autoidle list for later processing. Returns 0 on success, + * negative error value on failure. + */ +int __init of_ti_clk_autoidle_setup(struct device_node *node) +{ + u32 shift; + struct clk_ti_autoidle *clk; + int ret; + + /* Check if this clock has autoidle support or not */ + if (of_property_read_u32(node, "ti,autoidle-shift", &shift)) + return 0; + + clk = kzalloc(sizeof(*clk), GFP_KERNEL); + + if (!clk) + return -ENOMEM; + + clk->shift = shift; + clk->name = ti_dt_clk_name(node); + ret = ti_clk_get_reg_addr(node, 0, &clk->reg); + if (ret) { + kfree(clk); + return ret; + } + + if (of_property_read_bool(node, "ti,invert-autoidle-bit")) + clk->flags |= AUTOIDLE_LOW; + + list_add(&clk->node, &autoidle_clks); + + return 0; +} + +/** + * omap2_clk_enable_autoidle_all - enable autoidle on all OMAP clocks that + * support it + * + * Enable clock autoidle on all OMAP clocks that have allow_idle + * function pointers associated with them. This function is intended + * to be temporary until support for this is added to the common clock + * code. Returns 0. + */ +int omap2_clk_enable_autoidle_all(void) +{ + int ret; + + ret = omap2_clk_for_each(_omap2_clk_allow_idle); + if (ret) + return ret; + + _clk_generic_allow_autoidle_all(); + + return 0; +} + +/** + * omap2_clk_disable_autoidle_all - disable autoidle on all OMAP clocks that + * support it + * + * Disable clock autoidle on all OMAP clocks that have allow_idle + * function pointers associated with them. This function is intended + * to be temporary until support for this is added to the common clock + * code. Returns 0. + */ +int omap2_clk_disable_autoidle_all(void) +{ + int ret; + + ret = omap2_clk_for_each(_omap2_clk_deny_idle); + if (ret) + return ret; + + _clk_generic_deny_autoidle_all(); + + return 0; +} |