diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/tegra/clk-super.c | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/clk/tegra/clk-super.c b/drivers/clk/tegra/clk-super.c new file mode 100644 index 000000000..a98a42039 --- /dev/null +++ b/drivers/clk/tegra/clk-super.c @@ -0,0 +1,274 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved. + */ + +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/clk-provider.h> + +#include "clk.h" + +#define SUPER_STATE_IDLE 0 +#define SUPER_STATE_RUN 1 +#define SUPER_STATE_IRQ 2 +#define SUPER_STATE_FIQ 3 + +#define SUPER_STATE_SHIFT 28 +#define SUPER_STATE_MASK ((BIT(SUPER_STATE_IDLE) | BIT(SUPER_STATE_RUN) | \ + BIT(SUPER_STATE_IRQ) | BIT(SUPER_STATE_FIQ)) \ + << SUPER_STATE_SHIFT) + +#define SUPER_LP_DIV2_BYPASS (1 << 16) + +#define super_state(s) (BIT(s) << SUPER_STATE_SHIFT) +#define super_state_to_src_shift(m, s) ((m->width * s)) +#define super_state_to_src_mask(m) (((1 << m->width) - 1)) + +#define CCLK_SRC_PLLP_OUT0 4 +#define CCLK_SRC_PLLP_OUT4 5 + +static u8 clk_super_get_parent(struct clk_hw *hw) +{ + struct tegra_clk_super_mux *mux = to_clk_super_mux(hw); + u32 val, state; + u8 source, shift; + + val = readl_relaxed(mux->reg); + + state = val & SUPER_STATE_MASK; + + BUG_ON((state != super_state(SUPER_STATE_RUN)) && + (state != super_state(SUPER_STATE_IDLE))); + shift = (state == super_state(SUPER_STATE_IDLE)) ? + super_state_to_src_shift(mux, SUPER_STATE_IDLE) : + super_state_to_src_shift(mux, SUPER_STATE_RUN); + + source = (val >> shift) & super_state_to_src_mask(mux); + + /* + * If LP_DIV2_BYPASS is not set and PLLX is current parent then + * PLLX/2 is the input source to CCLKLP. + */ + if ((mux->flags & TEGRA_DIVIDER_2) && !(val & SUPER_LP_DIV2_BYPASS) && + (source == mux->pllx_index)) + source = mux->div2_index; + + return source; +} + +static int clk_super_set_parent(struct clk_hw *hw, u8 index) +{ + struct tegra_clk_super_mux *mux = to_clk_super_mux(hw); + u32 val, state; + int err = 0; + u8 parent_index, shift; + unsigned long flags = 0; + + if (mux->lock) + spin_lock_irqsave(mux->lock, flags); + + val = readl_relaxed(mux->reg); + state = val & SUPER_STATE_MASK; + BUG_ON((state != super_state(SUPER_STATE_RUN)) && + (state != super_state(SUPER_STATE_IDLE))); + shift = (state == super_state(SUPER_STATE_IDLE)) ? + super_state_to_src_shift(mux, SUPER_STATE_IDLE) : + super_state_to_src_shift(mux, SUPER_STATE_RUN); + + /* + * For LP mode super-clock switch between PLLX direct + * and divided-by-2 outputs is allowed only when other + * than PLLX clock source is current parent. + */ + if ((mux->flags & TEGRA_DIVIDER_2) && ((index == mux->div2_index) || + (index == mux->pllx_index))) { + parent_index = clk_super_get_parent(hw); + if ((parent_index == mux->div2_index) || + (parent_index == mux->pllx_index)) { + err = -EINVAL; + goto out; + } + + val ^= SUPER_LP_DIV2_BYPASS; + writel_relaxed(val, mux->reg); + udelay(2); + + if (index == mux->div2_index) + index = mux->pllx_index; + } + + /* enable PLLP branches to CPU before selecting PLLP source */ + if ((mux->flags & TEGRA210_CPU_CLK) && + (index == CCLK_SRC_PLLP_OUT0 || index == CCLK_SRC_PLLP_OUT4)) + tegra_clk_set_pllp_out_cpu(true); + + val &= ~((super_state_to_src_mask(mux)) << shift); + val |= (index & (super_state_to_src_mask(mux))) << shift; + + writel_relaxed(val, mux->reg); + udelay(2); + + /* disable PLLP branches to CPU if not used */ + if ((mux->flags & TEGRA210_CPU_CLK) && + index != CCLK_SRC_PLLP_OUT0 && index != CCLK_SRC_PLLP_OUT4) + tegra_clk_set_pllp_out_cpu(false); + +out: + if (mux->lock) + spin_unlock_irqrestore(mux->lock, flags); + + return err; +} + +static void clk_super_mux_restore_context(struct clk_hw *hw) +{ + int parent_id; + + parent_id = clk_hw_get_parent_index(hw); + if (WARN_ON(parent_id < 0)) + return; + + clk_super_set_parent(hw, parent_id); +} + +static const struct clk_ops tegra_clk_super_mux_ops = { + .get_parent = clk_super_get_parent, + .set_parent = clk_super_set_parent, + .restore_context = clk_super_mux_restore_context, +}; + +static long clk_super_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct tegra_clk_super_mux *super = to_clk_super_mux(hw); + struct clk_hw *div_hw = &super->frac_div.hw; + + __clk_hw_set_clk(div_hw, hw); + + return super->div_ops->round_rate(div_hw, rate, parent_rate); +} + +static unsigned long clk_super_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct tegra_clk_super_mux *super = to_clk_super_mux(hw); + struct clk_hw *div_hw = &super->frac_div.hw; + + __clk_hw_set_clk(div_hw, hw); + + return super->div_ops->recalc_rate(div_hw, parent_rate); +} + +static int clk_super_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct tegra_clk_super_mux *super = to_clk_super_mux(hw); + struct clk_hw *div_hw = &super->frac_div.hw; + + __clk_hw_set_clk(div_hw, hw); + + return super->div_ops->set_rate(div_hw, rate, parent_rate); +} + +static void clk_super_restore_context(struct clk_hw *hw) +{ + struct tegra_clk_super_mux *super = to_clk_super_mux(hw); + struct clk_hw *div_hw = &super->frac_div.hw; + int parent_id; + + parent_id = clk_hw_get_parent_index(hw); + if (WARN_ON(parent_id < 0)) + return; + + super->div_ops->restore_context(div_hw); + clk_super_set_parent(hw, parent_id); +} + +const struct clk_ops tegra_clk_super_ops = { + .get_parent = clk_super_get_parent, + .set_parent = clk_super_set_parent, + .set_rate = clk_super_set_rate, + .round_rate = clk_super_round_rate, + .recalc_rate = clk_super_recalc_rate, + .restore_context = clk_super_restore_context, +}; + +struct clk *tegra_clk_register_super_mux(const char *name, + const char **parent_names, u8 num_parents, + unsigned long flags, void __iomem *reg, u8 clk_super_flags, + u8 width, u8 pllx_index, u8 div2_index, spinlock_t *lock) +{ + struct tegra_clk_super_mux *super; + struct clk *clk; + struct clk_init_data init; + + super = kzalloc(sizeof(*super), GFP_KERNEL); + if (!super) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &tegra_clk_super_mux_ops; + init.flags = flags; + init.parent_names = parent_names; + init.num_parents = num_parents; + + super->reg = reg; + super->pllx_index = pllx_index; + super->div2_index = div2_index; + super->lock = lock; + super->width = width; + super->flags = clk_super_flags; + + /* Data in .init is copied by clk_register(), so stack variable OK */ + super->hw.init = &init; + + clk = tegra_clk_dev_register(&super->hw); + if (IS_ERR(clk)) + kfree(super); + + return clk; +} + +struct clk *tegra_clk_register_super_clk(const char *name, + const char * const *parent_names, u8 num_parents, + unsigned long flags, void __iomem *reg, u8 clk_super_flags, + spinlock_t *lock) +{ + struct tegra_clk_super_mux *super; + struct clk *clk; + struct clk_init_data init; + + super = kzalloc(sizeof(*super), GFP_KERNEL); + if (!super) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &tegra_clk_super_ops; + init.flags = flags; + init.parent_names = parent_names; + init.num_parents = num_parents; + + super->reg = reg; + super->lock = lock; + super->width = 4; + super->flags = clk_super_flags; + super->frac_div.reg = reg + 4; + super->frac_div.shift = 16; + super->frac_div.width = 8; + super->frac_div.frac_width = 1; + super->frac_div.lock = lock; + super->div_ops = &tegra_clk_frac_div_ops; + + /* Data in .init is copied by clk_register(), so stack variable OK */ + super->hw.init = &init; + + clk = clk_register(NULL, &super->hw); + if (IS_ERR(clk)) + kfree(super); + + return clk; +} |