diff options
Diffstat (limited to 'drivers/clk/st/clk-flexgen.c')
| -rw-r--r-- | drivers/clk/st/clk-flexgen.c | 331 |
1 files changed, 331 insertions, 0 deletions
diff --git a/drivers/clk/st/clk-flexgen.c b/drivers/clk/st/clk-flexgen.c new file mode 100644 index 00000000000..2282cef9f2f --- /dev/null +++ b/drivers/clk/st/clk-flexgen.c @@ -0,0 +1,331 @@ +/* + * clk-flexgen.c + * + * Copyright (C) ST-Microelectronics SA 2013 + * Author: Maxime Coquelin <maxime.coquelin@st.com> for ST-Microelectronics. + * License terms: GNU General Public License (GPL), version 2 */ + +#include <linux/clk-provider.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/err.h> +#include <linux/string.h> +#include <linux/of.h> +#include <linux/of_address.h> + +struct flexgen { + struct clk_hw hw; + + /* Crossbar */ + struct clk_mux mux; + /* Pre-divisor's gate */ + struct clk_gate pgate; + /* Pre-divisor */ + struct clk_divider pdiv; + /* Final divisor's gate */ + struct clk_gate fgate; + /* Final divisor */ + struct clk_divider fdiv; +}; + +#define to_flexgen(_hw) container_of(_hw, struct flexgen, hw) + +static int flexgen_enable(struct clk_hw *hw) +{ + struct flexgen *flexgen = to_flexgen(hw); + struct clk_hw *pgate_hw = &flexgen->pgate.hw; + struct clk_hw *fgate_hw = &flexgen->fgate.hw; + + pgate_hw->clk = hw->clk; + fgate_hw->clk = hw->clk; + + clk_gate_ops.enable(pgate_hw); + + clk_gate_ops.enable(fgate_hw); + + pr_debug("%s: flexgen output enabled\n", __clk_get_name(hw->clk)); + return 0; +} + +static void flexgen_disable(struct clk_hw *hw) +{ + struct flexgen *flexgen = to_flexgen(hw); + struct clk_hw *fgate_hw = &flexgen->fgate.hw; + + /* disable only the final gate */ + fgate_hw->clk = hw->clk; + + clk_gate_ops.disable(fgate_hw); + + pr_debug("%s: flexgen output disabled\n", __clk_get_name(hw->clk)); +} + +static int flexgen_is_enabled(struct clk_hw *hw) +{ + struct flexgen *flexgen = to_flexgen(hw); + struct clk_hw *fgate_hw = &flexgen->fgate.hw; + + fgate_hw->clk = hw->clk; + + if (!clk_gate_ops.is_enabled(fgate_hw)) + return 0; + + return 1; +} + +static u8 flexgen_get_parent(struct clk_hw *hw) +{ + struct flexgen *flexgen = to_flexgen(hw); + struct clk_hw *mux_hw = &flexgen->mux.hw; + + mux_hw->clk = hw->clk; + + return clk_mux_ops.get_parent(mux_hw); +} + +static int flexgen_set_parent(struct clk_hw *hw, u8 index) +{ + struct flexgen *flexgen = to_flexgen(hw); + struct clk_hw *mux_hw = &flexgen->mux.hw; + + mux_hw->clk = hw->clk; + + return clk_mux_ops.set_parent(mux_hw, index); +} + +static inline unsigned long +clk_best_div(unsigned long parent_rate, unsigned long rate) +{ + return parent_rate / rate + ((rate > (2*(parent_rate % rate))) ? 0 : 1); +} + +static long flexgen_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + unsigned long div; + + /* Round div according to exact prate and wished rate */ + div = clk_best_div(*prate, rate); + + if (__clk_get_flags(hw->clk) & CLK_SET_RATE_PARENT) { + *prate = rate * div; + return rate; + } + + return *prate / div; +} + +unsigned long flexgen_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct flexgen *flexgen = to_flexgen(hw); + struct clk_hw *pdiv_hw = &flexgen->pdiv.hw; + struct clk_hw *fdiv_hw = &flexgen->fdiv.hw; + unsigned long mid_rate; + + pdiv_hw->clk = hw->clk; + fdiv_hw->clk = hw->clk; + + mid_rate = clk_divider_ops.recalc_rate(pdiv_hw, parent_rate); + + return clk_divider_ops.recalc_rate(fdiv_hw, mid_rate); +} + +static int flexgen_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct flexgen *flexgen = to_flexgen(hw); + struct clk_hw *pdiv_hw = &flexgen->pdiv.hw; + struct clk_hw *fdiv_hw = &flexgen->fdiv.hw; + unsigned long primary_div = 0; + int ret = 0; + + pdiv_hw->clk = hw->clk; + fdiv_hw->clk = hw->clk; + + primary_div = clk_best_div(parent_rate, rate); + + clk_divider_ops.set_rate(fdiv_hw, parent_rate, parent_rate); + ret = clk_divider_ops.set_rate(pdiv_hw, rate, rate * primary_div); + + return ret; +} + +static const struct clk_ops flexgen_ops = { + .enable = flexgen_enable, + .disable = flexgen_disable, + .is_enabled = flexgen_is_enabled, + .get_parent = flexgen_get_parent, + .set_parent = flexgen_set_parent, + .round_rate = flexgen_round_rate, + .recalc_rate = flexgen_recalc_rate, + .set_rate = flexgen_set_rate, +}; + +struct clk *clk_register_flexgen(const char *name, + const char **parent_names, u8 num_parents, + void __iomem *reg, spinlock_t *lock, u32 idx, + unsigned long flexgen_flags) { + struct flexgen *fgxbar; + struct clk *clk; + struct clk_init_data init; + u32 xbar_shift; + void __iomem *xbar_reg, *fdiv_reg; + + fgxbar = kzalloc(sizeof(struct flexgen), GFP_KERNEL); + if (!fgxbar) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &flexgen_ops; + init.flags = CLK_IS_BASIC | flexgen_flags; + init.parent_names = parent_names; + init.num_parents = num_parents; + + xbar_reg = reg + 0x18 + (idx & ~0x3); + xbar_shift = (idx % 4) * 0x8; + fdiv_reg = reg + 0x164 + idx * 4; + + /* Crossbar element config */ + fgxbar->mux.lock = lock; + fgxbar->mux.mask = BIT(6) - 1; + fgxbar->mux.reg = xbar_reg; + fgxbar->mux.shift = xbar_shift; + fgxbar->mux.table = NULL; + + + /* Pre-divider's gate config (in xbar register)*/ + fgxbar->pgate.lock = lock; + fgxbar->pgate.reg = xbar_reg; + fgxbar->pgate.bit_idx = xbar_shift + 6; + + /* Pre-divider config */ + fgxbar->pdiv.lock = lock; + fgxbar->pdiv.reg = reg + 0x58 + idx * 4; + fgxbar->pdiv.width = 10; + + /* Final divider's gate config */ + fgxbar->fgate.lock = lock; + fgxbar->fgate.reg = fdiv_reg; + fgxbar->fgate.bit_idx = 6; + + /* Final divider config */ + fgxbar->fdiv.lock = lock; + fgxbar->fdiv.reg = fdiv_reg; + fgxbar->fdiv.width = 6; + + fgxbar->hw.init = &init; + + clk = clk_register(NULL, &fgxbar->hw); + if (IS_ERR(clk)) + kfree(fgxbar); + else + pr_debug("%s: parent %s rate %u\n", + __clk_get_name(clk), + __clk_get_name(clk_get_parent(clk)), + (unsigned int)clk_get_rate(clk)); + return clk; +} + +static const char ** __init flexgen_get_parents(struct device_node *np, + int *num_parents) +{ + const char **parents; + int nparents, i; + + nparents = of_count_phandle_with_args(np, "clocks", "#clock-cells"); + if (WARN_ON(nparents <= 0)) + return NULL; + + parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL); + if (!parents) + return NULL; + + for (i = 0; i < nparents; i++) + parents[i] = of_clk_get_parent_name(np, i); + + *num_parents = nparents; + return parents; +} + +void __init st_of_flexgen_setup(struct device_node *np) +{ + struct device_node *pnode; + void __iomem *reg; + struct clk_onecell_data *clk_data; + const char **parents; + int num_parents, i; + spinlock_t *rlock = NULL; + unsigned long flex_flags = 0; + + pnode = of_get_parent(np); + if (!pnode) + return; + + reg = of_iomap(pnode, 0); + if (!reg) + return; + + parents = flexgen_get_parents(np, &num_parents); + if (!parents) + return; + + clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL); + if (!clk_data) + goto err; + + clk_data->clk_num = of_property_count_strings(np , + "clock-output-names"); + if (clk_data->clk_num <= 0) { + pr_err("%s: Failed to get number of output clocks (%d)", + __func__, clk_data->clk_num); + goto err; + } + + clk_data->clks = kcalloc(clk_data->clk_num, sizeof(struct clk *), + GFP_KERNEL); + if (!clk_data->clks) + goto err; + + rlock = kzalloc(sizeof(spinlock_t), GFP_KERNEL); + if (!rlock) + goto err; + + for (i = 0; i < clk_data->clk_num; i++) { + struct clk *clk; + const char *clk_name; + + if (of_property_read_string_index(np, "clock-output-names", + i, &clk_name)) { + break; + } + + /* + * If we read an empty clock name then the output is unused + */ + if (*clk_name == '\0') + continue; + + clk = clk_register_flexgen(clk_name, parents, num_parents, + reg, rlock, i, flex_flags); + + if (IS_ERR(clk)) + goto err; + + clk_data->clks[i] = clk; + } + + kfree(parents); + of_clk_add_provider(np, of_clk_src_onecell_get, clk_data); + + return; + +err: + if (clk_data) + kfree(clk_data->clks); + kfree(clk_data); + kfree(parents); + kfree(rlock); +} +CLK_OF_DECLARE(flexgen, "st,flexgen", st_of_flexgen_setup); |