From 94885faf9dbcc2ca704d60e7db2f2b87e0b0fe6e Mon Sep 17 00:00:00 2001 From: Gabriel FERNANDEZ Date: Thu, 27 Feb 2014 16:24:14 +0100 Subject: [PATCH] clk: st: Support for DIVMUX and PreDiv Clocks The patch supports the DIVMUX and PreDiv clocks used by ClockGenA(s) DIVMUX clock : Divider-Multiplexer-Gate inside ClockGenA(s) It includes support for each channel : 3-parent Multiplexer, Divider for each Parent, Gate to switch OFF the output channel. The clock is implemented using generic clocks implemented in the kernel clk_divider and clk_mux. PreDiv clock : Fixed Divider Clock used inside ClockGenA(s) to divide the oscillator clock by factor-of-16. The clock is implemented using generic clocks implemented in the kernel clk_divider. Signed-off-by: Pankaj Dev Signed-off-by: Gabriel Fernandez Signed-off-by: Mike Turquette --- drivers/clk/Makefile | 1 + drivers/clk/st/Makefile | 1 + drivers/clk/st/clkgen-mux.c | 529 ++++++++++++++++++++++++++++++++++++ 3 files changed, 531 insertions(+) create mode 100644 drivers/clk/st/Makefile create mode 100644 drivers/clk/st/clkgen-mux.c diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index b5221b712387..85a33e6d765c 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -45,6 +45,7 @@ obj-$(CONFIG_ARCH_SHMOBILE_MULTI) += shmobile/ obj-$(CONFIG_ARCH_SIRF) += sirf/ obj-$(CONFIG_ARCH_SOCFPGA) += socfpga/ obj-$(CONFIG_PLAT_SPEAR) += spear/ +obj-$(CONFIG_ARCH_STI) += st/ obj-$(CONFIG_ARCH_SUNXI) += sunxi/ obj-$(CONFIG_ARCH_TEGRA) += tegra/ obj-$(CONFIG_ARCH_OMAP2PLUS) += ti/ diff --git a/drivers/clk/st/Makefile b/drivers/clk/st/Makefile new file mode 100644 index 000000000000..e42b370edef9 --- /dev/null +++ b/drivers/clk/st/Makefile @@ -0,0 +1 @@ +obj-y += clkgen-mux.o diff --git a/drivers/clk/st/clkgen-mux.c b/drivers/clk/st/clkgen-mux.c new file mode 100644 index 000000000000..65d702c2df8d --- /dev/null +++ b/drivers/clk/st/clkgen-mux.c @@ -0,0 +1,529 @@ +/* + * clkgen-mux.c: ST GEN-MUX Clock driver + * + * Copyright (C) 2014 STMicroelectronics (R&D) Limited + * + * Authors: Stephen Gallimore + * Pankaj Dev + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + */ + +#include +#include +#include + +static DEFINE_SPINLOCK(clkgena_divmux_lock); + +static const char ** __init clkgen_mux_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 ERR_PTR(-EINVAL); + + parents = kzalloc(nparents * sizeof(const char *), GFP_KERNEL); + if (!parents) + return ERR_PTR(-ENOMEM); + + for (i = 0; i < nparents; i++) + parents[i] = of_clk_get_parent_name(np, i); + + *num_parents = nparents; + return parents; +} + +/** + * DOC: Clock mux with a programmable divider on each of its three inputs. + * The mux has an input setting which effectively gates its output. + * + * Traits of this clock: + * prepare - clk_(un)prepare only ensures parent is (un)prepared + * enable - clk_enable and clk_disable are functional & control gating + * rate - set rate is supported + * parent - set/get parent + */ + +#define NUM_INPUTS 3 + +struct clkgena_divmux { + struct clk_hw hw; + /* Subclassed mux and divider structures */ + struct clk_mux mux; + struct clk_divider div[NUM_INPUTS]; + /* Enable/running feedback register bits for each input */ + void __iomem *feedback_reg[NUM_INPUTS]; + int feedback_bit_idx; + + u8 muxsel; +}; + +#define to_clkgena_divmux(_hw) container_of(_hw, struct clkgena_divmux, hw) + +struct clkgena_divmux_data { + int num_outputs; + int mux_offset; + int mux_offset2; + int mux_start_bit; + int div_offsets[NUM_INPUTS]; + int fb_offsets[NUM_INPUTS]; + int fb_start_bit_idx; +}; + +#define CKGAX_CLKOPSRC_SWITCH_OFF 0x3 + +static int clkgena_divmux_is_running(struct clkgena_divmux *mux) +{ + u32 regval = readl(mux->feedback_reg[mux->muxsel]); + u32 running = regval & BIT(mux->feedback_bit_idx); + return !!running; +} + +static int clkgena_divmux_enable(struct clk_hw *hw) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + struct clk_hw *mux_hw = &genamux->mux.hw; + unsigned long timeout; + int ret = 0; + + mux_hw->clk = hw->clk; + + ret = clk_mux_ops.set_parent(mux_hw, genamux->muxsel); + if (ret) + return ret; + + timeout = jiffies + msecs_to_jiffies(10); + + while (!clkgena_divmux_is_running(genamux)) { + if (time_after(jiffies, timeout)) + return -ETIMEDOUT; + cpu_relax(); + } + + return 0; +} + +static void clkgena_divmux_disable(struct clk_hw *hw) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + struct clk_hw *mux_hw = &genamux->mux.hw; + + mux_hw->clk = hw->clk; + + clk_mux_ops.set_parent(mux_hw, CKGAX_CLKOPSRC_SWITCH_OFF); +} + +static int clkgena_divmux_is_enabled(struct clk_hw *hw) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + struct clk_hw *mux_hw = &genamux->mux.hw; + + mux_hw->clk = hw->clk; + + return (s8)clk_mux_ops.get_parent(mux_hw) > 0; +} + +u8 clkgena_divmux_get_parent(struct clk_hw *hw) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + struct clk_hw *mux_hw = &genamux->mux.hw; + + mux_hw->clk = hw->clk; + + genamux->muxsel = clk_mux_ops.get_parent(mux_hw); + if ((s8)genamux->muxsel < 0) { + pr_debug("%s: %s: Invalid parent, setting to default.\n", + __func__, __clk_get_name(hw->clk)); + genamux->muxsel = 0; + } + + return genamux->muxsel; +} + +static int clkgena_divmux_set_parent(struct clk_hw *hw, u8 index) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + + if (index >= CKGAX_CLKOPSRC_SWITCH_OFF) + return -EINVAL; + + genamux->muxsel = index; + + /* + * If the mux is already enabled, call enable directly to set the + * new mux position and wait for it to start running again. Otherwise + * do nothing. + */ + if (clkgena_divmux_is_enabled(hw)) + clkgena_divmux_enable(hw); + + return 0; +} + +unsigned long clkgena_divmux_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw; + + div_hw->clk = hw->clk; + + return clk_divider_ops.recalc_rate(div_hw, parent_rate); +} + +static int clkgena_divmux_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw; + + div_hw->clk = hw->clk; + + return clk_divider_ops.set_rate(div_hw, rate, parent_rate); +} + +static long clkgena_divmux_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *prate) +{ + struct clkgena_divmux *genamux = to_clkgena_divmux(hw); + struct clk_hw *div_hw = &genamux->div[genamux->muxsel].hw; + + div_hw->clk = hw->clk; + + return clk_divider_ops.round_rate(div_hw, rate, prate); +} + +static const struct clk_ops clkgena_divmux_ops = { + .enable = clkgena_divmux_enable, + .disable = clkgena_divmux_disable, + .is_enabled = clkgena_divmux_is_enabled, + .get_parent = clkgena_divmux_get_parent, + .set_parent = clkgena_divmux_set_parent, + .round_rate = clkgena_divmux_round_rate, + .recalc_rate = clkgena_divmux_recalc_rate, + .set_rate = clkgena_divmux_set_rate, +}; + +/** + * clk_register_genamux - register a genamux clock with the clock framework + */ +struct clk *clk_register_genamux(const char *name, + const char **parent_names, u8 num_parents, + void __iomem *reg, + const struct clkgena_divmux_data *muxdata, + u32 idx) +{ + /* + * Fixed constants across all ClockgenA variants + */ + const int mux_width = 2; + const int divider_width = 5; + struct clkgena_divmux *genamux; + struct clk *clk; + struct clk_init_data init; + int i; + + genamux = kzalloc(sizeof(*genamux), GFP_KERNEL); + if (!genamux) + return ERR_PTR(-ENOMEM); + + init.name = name; + init.ops = &clkgena_divmux_ops; + init.flags = CLK_IS_BASIC; + init.parent_names = parent_names; + init.num_parents = num_parents; + + genamux->mux.lock = &clkgena_divmux_lock; + genamux->mux.mask = BIT(mux_width) - 1; + genamux->mux.shift = muxdata->mux_start_bit + (idx * mux_width); + if (genamux->mux.shift > 31) { + /* + * We have spilled into the second mux register so + * adjust the register address and the bit shift accordingly + */ + genamux->mux.reg = reg + muxdata->mux_offset2; + genamux->mux.shift -= 32; + } else { + genamux->mux.reg = reg + muxdata->mux_offset; + } + + for (i = 0; i < NUM_INPUTS; i++) { + /* + * Divider config for each input + */ + void __iomem *divbase = reg + muxdata->div_offsets[i]; + genamux->div[i].width = divider_width; + genamux->div[i].reg = divbase + (idx * sizeof(u32)); + + /* + * Mux enabled/running feedback register for each input. + */ + genamux->feedback_reg[i] = reg + muxdata->fb_offsets[i]; + } + + genamux->feedback_bit_idx = muxdata->fb_start_bit_idx + idx; + genamux->hw.init = &init; + + clk = clk_register(NULL, &genamux->hw); + if (IS_ERR(clk)) { + kfree(genamux); + goto err; + } + + pr_debug("%s: parent %s rate %lu\n", + __clk_get_name(clk), + __clk_get_name(clk_get_parent(clk)), + clk_get_rate(clk)); +err: + return clk; +} + +static struct clkgena_divmux_data st_divmux_c65hs = { + .num_outputs = 4, + .mux_offset = 0x14, + .mux_start_bit = 0, + .div_offsets = { 0x800, 0x900, 0xb00 }, + .fb_offsets = { 0x18, 0x1c, 0x20 }, + .fb_start_bit_idx = 0, +}; + +static struct clkgena_divmux_data st_divmux_c65ls = { + .num_outputs = 14, + .mux_offset = 0x14, + .mux_offset2 = 0x24, + .mux_start_bit = 8, + .div_offsets = { 0x810, 0xa10, 0xb10 }, + .fb_offsets = { 0x18, 0x1c, 0x20 }, + .fb_start_bit_idx = 4, +}; + +static struct clkgena_divmux_data st_divmux_c32odf0 = { + .num_outputs = 8, + .mux_offset = 0x1c, + .mux_start_bit = 0, + .div_offsets = { 0x800, 0x900, 0xa60 }, + .fb_offsets = { 0x2c, 0x24, 0x28 }, + .fb_start_bit_idx = 0, +}; + +static struct clkgena_divmux_data st_divmux_c32odf1 = { + .num_outputs = 8, + .mux_offset = 0x1c, + .mux_start_bit = 16, + .div_offsets = { 0x820, 0x980, 0xa80 }, + .fb_offsets = { 0x2c, 0x24, 0x28 }, + .fb_start_bit_idx = 8, +}; + +static struct clkgena_divmux_data st_divmux_c32odf2 = { + .num_outputs = 8, + .mux_offset = 0x20, + .mux_start_bit = 0, + .div_offsets = { 0x840, 0xa20, 0xb10 }, + .fb_offsets = { 0x2c, 0x24, 0x28 }, + .fb_start_bit_idx = 16, +}; + +static struct clkgena_divmux_data st_divmux_c32odf3 = { + .num_outputs = 8, + .mux_offset = 0x20, + .mux_start_bit = 16, + .div_offsets = { 0x860, 0xa40, 0xb30 }, + .fb_offsets = { 0x2c, 0x24, 0x28 }, + .fb_start_bit_idx = 24, +}; + +static struct of_device_id clkgena_divmux_of_match[] = { + { + .compatible = "st,clkgena-divmux-c65-hs", + .data = &st_divmux_c65hs, + }, + { + .compatible = "st,clkgena-divmux-c65-ls", + .data = &st_divmux_c65ls, + }, + { + .compatible = "st,clkgena-divmux-c32-odf0", + .data = &st_divmux_c32odf0, + }, + { + .compatible = "st,clkgena-divmux-c32-odf1", + .data = &st_divmux_c32odf1, + }, + { + .compatible = "st,clkgena-divmux-c32-odf2", + .data = &st_divmux_c32odf2, + }, + { + .compatible = "st,clkgena-divmux-c32-odf3", + .data = &st_divmux_c32odf3, + }, + {} +}; + +static void __iomem * __init clkgen_get_register_base( + struct device_node *np) +{ + struct device_node *pnode; + void __iomem *reg = NULL; + + pnode = of_get_parent(np); + if (!pnode) + return NULL; + + reg = of_iomap(pnode, 0); + + of_node_put(pnode); + return reg; +} + +void __init st_of_clkgena_divmux_setup(struct device_node *np) +{ + const struct of_device_id *match; + const struct clkgena_divmux_data *data; + struct clk_onecell_data *clk_data; + void __iomem *reg; + const char **parents; + int num_parents = 0, i; + + match = of_match_node(clkgena_divmux_of_match, np); + if (WARN_ON(!match)) + return; + + data = (struct clkgena_divmux_data *)match->data; + + reg = clkgen_get_register_base(np); + if (!reg) + return; + + parents = clkgen_mux_get_parents(np, &num_parents); + if (IS_ERR(parents)) + return; + + clk_data = kzalloc(sizeof(*clk_data), GFP_KERNEL); + if (!clk_data) + goto err; + + clk_data->clk_num = data->num_outputs; + clk_data->clks = kzalloc(clk_data->clk_num * sizeof(struct clk *), + GFP_KERNEL); + + if (!clk_data->clks) + 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_genamux(clk_name, parents, num_parents, + reg, data, i); + + 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); +} +CLK_OF_DECLARE(clkgenadivmux, "st,clkgena-divmux", st_of_clkgena_divmux_setup); + +struct clkgena_prediv_data { + u32 offset; + u8 shift; + struct clk_div_table *table; +}; + +static struct clk_div_table prediv_table16[] = { + { .val = 0, .div = 1 }, + { .val = 1, .div = 16 }, + { .div = 0 }, +}; + +static struct clkgena_prediv_data prediv_c65_data = { + .offset = 0x4c, + .shift = 31, + .table = prediv_table16, +}; + +static struct clkgena_prediv_data prediv_c32_data = { + .offset = 0x50, + .shift = 1, + .table = prediv_table16, +}; + +static struct of_device_id clkgena_prediv_of_match[] = { + { .compatible = "st,clkgena-prediv-c65", .data = &prediv_c65_data }, + { .compatible = "st,clkgena-prediv-c32", .data = &prediv_c32_data }, + {} +}; + +void __init st_of_clkgena_prediv_setup(struct device_node *np) +{ + const struct of_device_id *match; + void __iomem *reg; + const char *parent_name, *clk_name; + struct clk *clk; + struct clkgena_prediv_data *data; + + match = of_match_node(clkgena_prediv_of_match, np); + if (!match) { + pr_err("%s: No matching data\n", __func__); + return; + } + + data = (struct clkgena_prediv_data *)match->data; + + reg = clkgen_get_register_base(np); + if (!reg) + return; + + parent_name = of_clk_get_parent_name(np, 0); + if (!parent_name) + return; + + if (of_property_read_string_index(np, "clock-output-names", + 0, &clk_name)) + return; + + clk = clk_register_divider_table(NULL, clk_name, parent_name, 0, + reg + data->offset, data->shift, 1, + 0, data->table, NULL); + if (IS_ERR(clk)) + return; + + of_clk_add_provider(np, of_clk_src_simple_get, clk); + 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_OF_DECLARE(clkgenaprediv, "st,clkgena-prediv", st_of_clkgena_prediv_setup); -- 2.20.1