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Diffstat (limited to '')
| -rw-r--r-- | drivers/clk/ti/autoidle.c | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/drivers/clk/ti/autoidle.c b/drivers/clk/ti/autoidle.c new file mode 100644 index 000000000..7bb9afbe4 --- /dev/null +++ b/drivers/clk/ti/autoidle.c @@ -0,0 +1,232 @@ +/* + * TI clock autoidle support + * + * Copyright (C) 2013 Texas Instruments, Inc. + * + * Tero Kristo <t-kristo@ti.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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-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); +static LIST_HEAD(clk_hw_omap_clocks); + +/** + * 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_omap *c; + + c = to_clk_hw_omap(__clk_get_hw(clk)); + if (c->ops && c->ops->deny_idle) + c->ops->deny_idle(c); + return 0; +} + +/** + * 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_omap *c; + + c = to_clk_hw_omap(__clk_get_hw(clk)); + if (c->ops && c->ops->allow_idle) + c->ops->allow_idle(c); + return 0; +} + +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 = node->name; + 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_init_clk_hw_omap_clocks - initialize an OMAP clock + * @hw: struct clk_hw * to initialize + * + * Add an OMAP clock @clk to the internal list of OMAP clocks. Used + * temporarily for autoidle handling, until this support can be + * integrated into the common clock framework code in some way. No + * return value. + */ +void omap2_init_clk_hw_omap_clocks(struct clk_hw *hw) +{ + struct clk_hw_omap *c; + + if (clk_hw_get_flags(hw) & CLK_IS_BASIC) + return; + + c = to_clk_hw_omap(hw); + list_add(&c->node, &clk_hw_omap_clocks); +} + +/** + * 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) +{ + struct clk_hw_omap *c; + + list_for_each_entry(c, &clk_hw_omap_clocks, node) + if (c->ops && c->ops->allow_idle) + c->ops->allow_idle(c); + + _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) +{ + struct clk_hw_omap *c; + + list_for_each_entry(c, &clk_hw_omap_clocks, node) + if (c->ops && c->ops->deny_idle) + c->ops->deny_idle(c); + + _clk_generic_deny_autoidle_all(); + + return 0; +} |