X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Fclk%2Fmvebu%2Fcommon.c;fp=kernel%2Fdrivers%2Fclk%2Fmvebu%2Fcommon.c;h=15b370ff37481a61e4351377793d5619e14a6cd8;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/clk/mvebu/common.c b/kernel/drivers/clk/mvebu/common.c new file mode 100644 index 000000000..15b370ff3 --- /dev/null +++ b/kernel/drivers/clk/mvebu/common.c @@ -0,0 +1,299 @@ +/* + * Marvell EBU SoC common clock handling + * + * Copyright (C) 2012 Marvell + * + * Gregory CLEMENT + * Sebastian Hesselbarth + * Andrew Lunn + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "common.h" + +/* + * Core Clocks + */ + +#define SSCG_CONF_MODE(reg) (((reg) >> 16) & 0x3) +#define SSCG_SPREAD_DOWN 0x0 +#define SSCG_SPREAD_UP 0x1 +#define SSCG_SPREAD_CENTRAL 0x2 +#define SSCG_CONF_LOW(reg) (((reg) >> 8) & 0xFF) +#define SSCG_CONF_HIGH(reg) ((reg) & 0xFF) + +static struct clk_onecell_data clk_data; + +/* + * This function can be used by the Kirkwood, the Armada 370, the + * Armada XP and the Armada 375 SoC. The name of the function was + * chosen following the dt convention: using the first known SoC + * compatible with it. + */ +u32 kirkwood_fix_sscg_deviation(u32 system_clk) +{ + struct device_node *sscg_np = NULL; + void __iomem *sscg_map; + u32 sscg_reg; + s32 low_bound, high_bound; + u64 freq_swing_half; + + sscg_np = of_find_node_by_name(NULL, "sscg"); + if (sscg_np == NULL) { + pr_err("cannot get SSCG register node\n"); + return system_clk; + } + + sscg_map = of_iomap(sscg_np, 0); + if (sscg_map == NULL) { + pr_err("cannot map SSCG register\n"); + goto out; + } + + sscg_reg = readl(sscg_map); + high_bound = SSCG_CONF_HIGH(sscg_reg); + low_bound = SSCG_CONF_LOW(sscg_reg); + + if ((high_bound - low_bound) <= 0) + goto out; + /* + * From Marvell engineer we got the following formula (when + * this code was written, the datasheet was erroneous) + * Spread percentage = 1/96 * (H - L) / H + * H = SSCG_High_Boundary + * L = SSCG_Low_Boundary + * + * As the deviation is half of spread then it lead to the + * following formula in the code. + * + * To avoid an overflow and not lose any significant digit in + * the same time we have to use a 64 bit integer. + */ + + freq_swing_half = (((u64)high_bound - (u64)low_bound) + * (u64)system_clk); + do_div(freq_swing_half, (2 * 96 * high_bound)); + + switch (SSCG_CONF_MODE(sscg_reg)) { + case SSCG_SPREAD_DOWN: + system_clk -= freq_swing_half; + break; + case SSCG_SPREAD_UP: + system_clk += freq_swing_half; + break; + case SSCG_SPREAD_CENTRAL: + default: + break; + } + + iounmap(sscg_map); + +out: + of_node_put(sscg_np); + + return system_clk; +} + +void __init mvebu_coreclk_setup(struct device_node *np, + const struct coreclk_soc_desc *desc) +{ + const char *tclk_name = "tclk"; + const char *cpuclk_name = "cpuclk"; + void __iomem *base; + unsigned long rate; + int n; + + base = of_iomap(np, 0); + if (WARN_ON(!base)) + return; + + /* Allocate struct for TCLK, cpu clk, and core ratio clocks */ + clk_data.clk_num = 2 + desc->num_ratios; + + /* One more clock for the optional refclk */ + if (desc->get_refclk_freq) + clk_data.clk_num += 1; + + clk_data.clks = kzalloc(clk_data.clk_num * sizeof(struct clk *), + GFP_KERNEL); + if (WARN_ON(!clk_data.clks)) { + iounmap(base); + return; + } + + /* Register TCLK */ + of_property_read_string_index(np, "clock-output-names", 0, + &tclk_name); + rate = desc->get_tclk_freq(base); + clk_data.clks[0] = clk_register_fixed_rate(NULL, tclk_name, NULL, + CLK_IS_ROOT, rate); + WARN_ON(IS_ERR(clk_data.clks[0])); + + /* Register CPU clock */ + of_property_read_string_index(np, "clock-output-names", 1, + &cpuclk_name); + rate = desc->get_cpu_freq(base); + + if (desc->is_sscg_enabled && desc->fix_sscg_deviation + && desc->is_sscg_enabled(base)) + rate = desc->fix_sscg_deviation(rate); + + clk_data.clks[1] = clk_register_fixed_rate(NULL, cpuclk_name, NULL, + CLK_IS_ROOT, rate); + WARN_ON(IS_ERR(clk_data.clks[1])); + + /* Register fixed-factor clocks derived from CPU clock */ + for (n = 0; n < desc->num_ratios; n++) { + const char *rclk_name = desc->ratios[n].name; + int mult, div; + + of_property_read_string_index(np, "clock-output-names", + 2+n, &rclk_name); + desc->get_clk_ratio(base, desc->ratios[n].id, &mult, &div); + clk_data.clks[2+n] = clk_register_fixed_factor(NULL, rclk_name, + cpuclk_name, 0, mult, div); + WARN_ON(IS_ERR(clk_data.clks[2+n])); + }; + + /* Register optional refclk */ + if (desc->get_refclk_freq) { + const char *name = "refclk"; + of_property_read_string_index(np, "clock-output-names", + 2 + desc->num_ratios, &name); + rate = desc->get_refclk_freq(base); + clk_data.clks[2 + desc->num_ratios] = + clk_register_fixed_rate(NULL, name, NULL, + CLK_IS_ROOT, rate); + WARN_ON(IS_ERR(clk_data.clks[2 + desc->num_ratios])); + } + + /* SAR register isn't needed anymore */ + iounmap(base); + + of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data); +} + +/* + * Clock Gating Control + */ + +DEFINE_SPINLOCK(ctrl_gating_lock); + +struct clk_gating_ctrl { + spinlock_t *lock; + struct clk **gates; + int num_gates; + void __iomem *base; + u32 saved_reg; +}; + +#define to_clk_gate(_hw) container_of(_hw, struct clk_gate, hw) + +static struct clk_gating_ctrl *ctrl; + +static struct clk *clk_gating_get_src( + struct of_phandle_args *clkspec, void *data) +{ + int n; + + if (clkspec->args_count < 1) + return ERR_PTR(-EINVAL); + + for (n = 0; n < ctrl->num_gates; n++) { + struct clk_gate *gate = + to_clk_gate(__clk_get_hw(ctrl->gates[n])); + if (clkspec->args[0] == gate->bit_idx) + return ctrl->gates[n]; + } + return ERR_PTR(-ENODEV); +} + +static int mvebu_clk_gating_suspend(void) +{ + ctrl->saved_reg = readl(ctrl->base); + return 0; +} + +static void mvebu_clk_gating_resume(void) +{ + writel(ctrl->saved_reg, ctrl->base); +} + +static struct syscore_ops clk_gate_syscore_ops = { + .suspend = mvebu_clk_gating_suspend, + .resume = mvebu_clk_gating_resume, +}; + +void __init mvebu_clk_gating_setup(struct device_node *np, + const struct clk_gating_soc_desc *desc) +{ + struct clk *clk; + void __iomem *base; + const char *default_parent = NULL; + int n; + + if (ctrl) { + pr_err("mvebu-clk-gating: cannot instantiate more than one gatable clock device\n"); + return; + } + + base = of_iomap(np, 0); + if (WARN_ON(!base)) + return; + + clk = of_clk_get(np, 0); + if (!IS_ERR(clk)) { + default_parent = __clk_get_name(clk); + clk_put(clk); + } + + ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL); + if (WARN_ON(!ctrl)) + goto ctrl_out; + + /* lock must already be initialized */ + ctrl->lock = &ctrl_gating_lock; + + ctrl->base = base; + + /* Count, allocate, and register clock gates */ + for (n = 0; desc[n].name;) + n++; + + ctrl->num_gates = n; + ctrl->gates = kzalloc(ctrl->num_gates * sizeof(struct clk *), + GFP_KERNEL); + if (WARN_ON(!ctrl->gates)) + goto gates_out; + + for (n = 0; n < ctrl->num_gates; n++) { + const char *parent = + (desc[n].parent) ? desc[n].parent : default_parent; + ctrl->gates[n] = clk_register_gate(NULL, desc[n].name, parent, + desc[n].flags, base, desc[n].bit_idx, + 0, ctrl->lock); + WARN_ON(IS_ERR(ctrl->gates[n])); + } + + of_clk_add_provider(np, clk_gating_get_src, ctrl); + + register_syscore_ops(&clk_gate_syscore_ops); + + return; +gates_out: + kfree(ctrl); +ctrl_out: + iounmap(base); +}