diff options
Diffstat (limited to 'drivers/clk/qcom/clk-krait.c')
| -rw-r--r-- | drivers/clk/qcom/clk-krait.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/clk/qcom/clk-krait.c b/drivers/clk/qcom/clk-krait.c new file mode 100644 index 0000000000..f5ce403e1e --- /dev/null +++ b/drivers/clk/qcom/clk-krait.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018, The Linux Foundation. All rights reserved. + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/clk-provider.h> +#include <linux/spinlock.h> + +#include <asm/krait-l2-accessors.h> + +#include "clk-krait.h" + +/* Secondary and primary muxes share the same cp15 register */ +static DEFINE_SPINLOCK(krait_clock_reg_lock); + +#define LPL_SHIFT 8 +#define SECCLKAGD BIT(4) + +static void __krait_mux_set_sel(struct krait_mux_clk *mux, int sel) +{ + unsigned long flags; + u32 regval; + + spin_lock_irqsave(&krait_clock_reg_lock, flags); + + regval = krait_get_l2_indirect_reg(mux->offset); + + /* apq/ipq8064 Errata: disable sec_src clock gating during switch. */ + if (mux->disable_sec_src_gating) { + regval |= SECCLKAGD; + krait_set_l2_indirect_reg(mux->offset, regval); + } + + regval &= ~(mux->mask << mux->shift); + regval |= (sel & mux->mask) << mux->shift; + if (mux->lpl) { + regval &= ~(mux->mask << (mux->shift + LPL_SHIFT)); + regval |= (sel & mux->mask) << (mux->shift + LPL_SHIFT); + } + krait_set_l2_indirect_reg(mux->offset, regval); + + /* apq/ipq8064 Errata: re-enabled sec_src clock gating. */ + if (mux->disable_sec_src_gating) { + regval &= ~SECCLKAGD; + krait_set_l2_indirect_reg(mux->offset, regval); + } + + /* Wait for switch to complete. */ + mb(); + udelay(1); + + /* + * Unlock now to make sure the mux register is not + * modified while switching to the new parent. + */ + spin_unlock_irqrestore(&krait_clock_reg_lock, flags); +} + +static int krait_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct krait_mux_clk *mux = to_krait_mux_clk(hw); + u32 sel; + + sel = clk_mux_index_to_val(mux->parent_map, 0, index); + mux->en_mask = sel; + /* Don't touch mux if CPU is off as it won't work */ + if (__clk_is_enabled(hw->clk)) + __krait_mux_set_sel(mux, sel); + + mux->reparent = true; + + return 0; +} + +static u8 krait_mux_get_parent(struct clk_hw *hw) +{ + struct krait_mux_clk *mux = to_krait_mux_clk(hw); + u32 sel; + + sel = krait_get_l2_indirect_reg(mux->offset); + sel >>= mux->shift; + sel &= mux->mask; + mux->en_mask = sel; + + return clk_mux_val_to_index(hw, mux->parent_map, 0, sel); +} + +const struct clk_ops krait_mux_clk_ops = { + .set_parent = krait_mux_set_parent, + .get_parent = krait_mux_get_parent, + .determine_rate = __clk_mux_determine_rate_closest, +}; +EXPORT_SYMBOL_GPL(krait_mux_clk_ops); + +/* The divider can divide by 2, 4, 6 and 8. But we only really need div-2. */ +static int krait_div2_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) +{ + req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw), req->rate * 2); + req->rate = DIV_ROUND_UP(req->best_parent_rate, 2); + return 0; +} + +static int krait_div2_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct krait_div2_clk *d = to_krait_div2_clk(hw); + unsigned long flags; + u32 val; + u32 mask = BIT(d->width) - 1; + + if (d->lpl) + mask = mask << (d->shift + LPL_SHIFT) | mask << d->shift; + else + mask <<= d->shift; + + spin_lock_irqsave(&krait_clock_reg_lock, flags); + val = krait_get_l2_indirect_reg(d->offset); + val &= ~mask; + krait_set_l2_indirect_reg(d->offset, val); + spin_unlock_irqrestore(&krait_clock_reg_lock, flags); + + return 0; +} + +static unsigned long +krait_div2_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) +{ + struct krait_div2_clk *d = to_krait_div2_clk(hw); + u32 mask = BIT(d->width) - 1; + u32 div; + + div = krait_get_l2_indirect_reg(d->offset); + div >>= d->shift; + div &= mask; + div = (div + 1) * 2; + + return DIV_ROUND_UP(parent_rate, div); +} + +const struct clk_ops krait_div2_clk_ops = { + .determine_rate = krait_div2_determine_rate, + .set_rate = krait_div2_set_rate, + .recalc_rate = krait_div2_recalc_rate, +}; +EXPORT_SYMBOL_GPL(krait_div2_clk_ops); |