diff options
Diffstat (limited to 'drivers/clk/qcom/krait-cc.c')
| -rw-r--r-- | drivers/clk/qcom/krait-cc.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/drivers/clk/qcom/krait-cc.c b/drivers/clk/qcom/krait-cc.c new file mode 100644 index 000000000000..4d4b657d33c3 --- /dev/null +++ b/drivers/clk/qcom/krait-cc.c @@ -0,0 +1,397 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2018, The Linux Foundation. All rights reserved. + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/slab.h> + +#include "clk-krait.h" + +static unsigned int sec_mux_map[] = { + 2, + 0, +}; + +static unsigned int pri_mux_map[] = { + 1, + 2, + 0, +}; + +/* + * Notifier function for switching the muxes to safe parent + * while the hfpll is getting reprogrammed. + */ +static int krait_notifier_cb(struct notifier_block *nb, + unsigned long event, + void *data) +{ + int ret = 0; + struct krait_mux_clk *mux = container_of(nb, struct krait_mux_clk, + clk_nb); + /* Switch to safe parent */ + if (event == PRE_RATE_CHANGE) { + mux->old_index = krait_mux_clk_ops.get_parent(&mux->hw); + ret = krait_mux_clk_ops.set_parent(&mux->hw, mux->safe_sel); + mux->reparent = false; + /* + * By the time POST_RATE_CHANGE notifier is called, + * clk framework itself would have changed the parent for the new rate. + * Only otherwise, put back to the old parent. + */ + } else if (event == POST_RATE_CHANGE) { + if (!mux->reparent) + ret = krait_mux_clk_ops.set_parent(&mux->hw, + mux->old_index); + } + + return notifier_from_errno(ret); +} + +static int krait_notifier_register(struct device *dev, struct clk *clk, + struct krait_mux_clk *mux) +{ + int ret = 0; + + mux->clk_nb.notifier_call = krait_notifier_cb; + ret = clk_notifier_register(clk, &mux->clk_nb); + if (ret) + dev_err(dev, "failed to register clock notifier: %d\n", ret); + + return ret; +} + +static int +krait_add_div(struct device *dev, int id, const char *s, unsigned int offset) +{ + struct krait_div2_clk *div; + struct clk_init_data init = { + .num_parents = 1, + .ops = &krait_div2_clk_ops, + .flags = CLK_SET_RATE_PARENT, + }; + const char *p_names[1]; + struct clk *clk; + + div = devm_kzalloc(dev, sizeof(*div), GFP_KERNEL); + if (!div) + return -ENOMEM; + + div->width = 2; + div->shift = 6; + div->lpl = id >= 0; + div->offset = offset; + div->hw.init = &init; + + init.name = kasprintf(GFP_KERNEL, "hfpll%s_div", s); + if (!init.name) + return -ENOMEM; + + init.parent_names = p_names; + p_names[0] = kasprintf(GFP_KERNEL, "hfpll%s", s); + if (!p_names[0]) { + kfree(init.name); + return -ENOMEM; + } + + clk = devm_clk_register(dev, &div->hw); + kfree(p_names[0]); + kfree(init.name); + + return PTR_ERR_OR_ZERO(clk); +} + +static int +krait_add_sec_mux(struct device *dev, int id, const char *s, + unsigned int offset, bool unique_aux) +{ + int ret; + struct krait_mux_clk *mux; + static const char *sec_mux_list[] = { + "acpu_aux", + "qsb", + }; + struct clk_init_data init = { + .parent_names = sec_mux_list, + .num_parents = ARRAY_SIZE(sec_mux_list), + .ops = &krait_mux_clk_ops, + .flags = CLK_SET_RATE_PARENT, + }; + struct clk *clk; + + mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL); + if (!mux) + return -ENOMEM; + + mux->offset = offset; + mux->lpl = id >= 0; + mux->mask = 0x3; + mux->shift = 2; + mux->parent_map = sec_mux_map; + mux->hw.init = &init; + mux->safe_sel = 0; + + init.name = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s); + if (!init.name) + return -ENOMEM; + + if (unique_aux) { + sec_mux_list[0] = kasprintf(GFP_KERNEL, "acpu%s_aux", s); + if (!sec_mux_list[0]) { + clk = ERR_PTR(-ENOMEM); + goto err_aux; + } + } + + clk = devm_clk_register(dev, &mux->hw); + + ret = krait_notifier_register(dev, clk, mux); + if (ret) + goto unique_aux; + +unique_aux: + if (unique_aux) + kfree(sec_mux_list[0]); +err_aux: + kfree(init.name); + return PTR_ERR_OR_ZERO(clk); +} + +static struct clk * +krait_add_pri_mux(struct device *dev, int id, const char *s, + unsigned int offset) +{ + int ret; + struct krait_mux_clk *mux; + const char *p_names[3]; + struct clk_init_data init = { + .parent_names = p_names, + .num_parents = ARRAY_SIZE(p_names), + .ops = &krait_mux_clk_ops, + .flags = CLK_SET_RATE_PARENT, + }; + struct clk *clk; + + mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL); + if (!mux) + return ERR_PTR(-ENOMEM); + + mux->mask = 0x3; + mux->shift = 0; + mux->offset = offset; + mux->lpl = id >= 0; + mux->parent_map = pri_mux_map; + mux->hw.init = &init; + mux->safe_sel = 2; + + init.name = kasprintf(GFP_KERNEL, "krait%s_pri_mux", s); + if (!init.name) + return ERR_PTR(-ENOMEM); + + p_names[0] = kasprintf(GFP_KERNEL, "hfpll%s", s); + if (!p_names[0]) { + clk = ERR_PTR(-ENOMEM); + goto err_p0; + } + + p_names[1] = kasprintf(GFP_KERNEL, "hfpll%s_div", s); + if (!p_names[1]) { + clk = ERR_PTR(-ENOMEM); + goto err_p1; + } + + p_names[2] = kasprintf(GFP_KERNEL, "krait%s_sec_mux", s); + if (!p_names[2]) { + clk = ERR_PTR(-ENOMEM); + goto err_p2; + } + + clk = devm_clk_register(dev, &mux->hw); + + ret = krait_notifier_register(dev, clk, mux); + if (ret) + goto err_p3; +err_p3: + kfree(p_names[2]); +err_p2: + kfree(p_names[1]); +err_p1: + kfree(p_names[0]); +err_p0: + kfree(init.name); + return clk; +} + +/* id < 0 for L2, otherwise id == physical CPU number */ +static struct clk *krait_add_clks(struct device *dev, int id, bool unique_aux) +{ + int ret; + unsigned int offset; + void *p = NULL; + const char *s; + struct clk *clk; + + if (id >= 0) { + offset = 0x4501 + (0x1000 * id); + s = p = kasprintf(GFP_KERNEL, "%d", id); + if (!s) + return ERR_PTR(-ENOMEM); + } else { + offset = 0x500; + s = "_l2"; + } + + ret = krait_add_div(dev, id, s, offset); + if (ret) { + clk = ERR_PTR(ret); + goto err; + } + + ret = krait_add_sec_mux(dev, id, s, offset, unique_aux); + if (ret) { + clk = ERR_PTR(ret); + goto err; + } + + clk = krait_add_pri_mux(dev, id, s, offset); +err: + kfree(p); + return clk; +} + +static struct clk *krait_of_get(struct of_phandle_args *clkspec, void *data) +{ + unsigned int idx = clkspec->args[0]; + struct clk **clks = data; + + if (idx >= 5) { + pr_err("%s: invalid clock index %d\n", __func__, idx); + return ERR_PTR(-EINVAL); + } + + return clks[idx] ? : ERR_PTR(-ENODEV); +} + +static const struct of_device_id krait_cc_match_table[] = { + { .compatible = "qcom,krait-cc-v1", (void *)1UL }, + { .compatible = "qcom,krait-cc-v2" }, + {} +}; +MODULE_DEVICE_TABLE(of, krait_cc_match_table); + +static int krait_cc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct of_device_id *id; + unsigned long cur_rate, aux_rate; + int cpu; + struct clk *clk; + struct clk **clks; + struct clk *l2_pri_mux_clk; + + id = of_match_device(krait_cc_match_table, dev); + if (!id) + return -ENODEV; + + /* Rate is 1 because 0 causes problems for __clk_mux_determine_rate */ + clk = clk_register_fixed_rate(dev, "qsb", NULL, 0, 1); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + if (!id->data) { + clk = clk_register_fixed_factor(dev, "acpu_aux", + "gpll0_vote", 0, 1, 2); + if (IS_ERR(clk)) + return PTR_ERR(clk); + } + + /* Krait configurations have at most 4 CPUs and one L2 */ + clks = devm_kcalloc(dev, 5, sizeof(*clks), GFP_KERNEL); + if (!clks) + return -ENOMEM; + + for_each_possible_cpu(cpu) { + clk = krait_add_clks(dev, cpu, id->data); + if (IS_ERR(clk)) + return PTR_ERR(clk); + clks[cpu] = clk; + } + + l2_pri_mux_clk = krait_add_clks(dev, -1, id->data); + if (IS_ERR(l2_pri_mux_clk)) + return PTR_ERR(l2_pri_mux_clk); + clks[4] = l2_pri_mux_clk; + + /* + * We don't want the CPU or L2 clocks to be turned off at late init + * if CPUFREQ or HOTPLUG configs are disabled. So, bump up the + * refcount of these clocks. Any cpufreq/hotplug manager can assume + * that the clocks have already been prepared and enabled by the time + * they take over. + */ + for_each_online_cpu(cpu) { + clk_prepare_enable(l2_pri_mux_clk); + WARN(clk_prepare_enable(clks[cpu]), + "Unable to turn on CPU%d clock", cpu); + } + + /* + * Force reinit of HFPLLs and muxes to overwrite any potential + * incorrect configuration of HFPLLs and muxes by the bootloader. + * While at it, also make sure the cores are running at known rates + * and print the current rate. + * + * The clocks are set to aux clock rate first to make sure the + * secondary mux is not sourcing off of QSB. The rate is then set to + * two different rates to force a HFPLL reinit under all + * circumstances. + */ + cur_rate = clk_get_rate(l2_pri_mux_clk); + aux_rate = 384000000; + if (cur_rate == 1) { + pr_info("L2 @ QSB rate. Forcing new rate.\n"); + cur_rate = aux_rate; + } + clk_set_rate(l2_pri_mux_clk, aux_rate); + clk_set_rate(l2_pri_mux_clk, 2); + clk_set_rate(l2_pri_mux_clk, cur_rate); + pr_info("L2 @ %lu KHz\n", clk_get_rate(l2_pri_mux_clk) / 1000); + for_each_possible_cpu(cpu) { + clk = clks[cpu]; + cur_rate = clk_get_rate(clk); + if (cur_rate == 1) { + pr_info("CPU%d @ QSB rate. Forcing new rate.\n", cpu); + cur_rate = aux_rate; + } + + clk_set_rate(clk, aux_rate); + clk_set_rate(clk, 2); + clk_set_rate(clk, cur_rate); + pr_info("CPU%d @ %lu KHz\n", cpu, clk_get_rate(clk) / 1000); + } + + of_clk_add_provider(dev->of_node, krait_of_get, clks); + + return 0; +} + +static struct platform_driver krait_cc_driver = { + .probe = krait_cc_probe, + .driver = { + .name = "krait-cc", + .of_match_table = krait_cc_match_table, + }, +}; +module_platform_driver(krait_cc_driver); + +MODULE_DESCRIPTION("Krait CPU Clock Driver"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:krait-cc"); |