diff options
Diffstat (limited to '')
-rw-r--r-- | drivers/clk/qcom/apcs-msm8916.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/drivers/clk/qcom/apcs-msm8916.c b/drivers/clk/qcom/apcs-msm8916.c new file mode 100644 index 000000000..89e073081 --- /dev/null +++ b/drivers/clk/qcom/apcs-msm8916.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Qualcomm APCS clock controller driver + * + * Copyright (c) 2017, Linaro Limited + * Author: Georgi Djakov <georgi.djakov@linaro.org> + */ + +#include <linux/clk.h> +#include <linux/clk-provider.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> + +#include "clk-regmap.h" +#include "clk-regmap-mux-div.h" + +static const u32 gpll0_a53cc_map[] = { 4, 5 }; + +static const struct clk_parent_data pdata[] = { + { .fw_name = "aux", .name = "gpll0_vote", }, + { .fw_name = "pll", .name = "a53pll", }, +}; + +/* + * We use the notifier function for switching to a temporary safe configuration + * (mux and divider), while the A53 PLL is reconfigured. + */ +static int a53cc_notifier_cb(struct notifier_block *nb, unsigned long event, + void *data) +{ + int ret = 0; + struct clk_regmap_mux_div *md = container_of(nb, + struct clk_regmap_mux_div, + clk_nb); + if (event == PRE_RATE_CHANGE) + /* set the mux and divider to safe frequency (400mhz) */ + ret = mux_div_set_src_div(md, 4, 3); + + return notifier_from_errno(ret); +} + +static int qcom_apcs_msm8916_clk_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device *parent = dev->parent; + struct device_node *np = parent->of_node; + struct clk_regmap_mux_div *a53cc; + struct regmap *regmap; + struct clk_init_data init = { }; + int ret = -ENODEV; + + regmap = dev_get_regmap(parent, NULL); + if (!regmap) { + dev_err(dev, "failed to get regmap: %d\n", ret); + return ret; + } + + a53cc = devm_kzalloc(dev, sizeof(*a53cc), GFP_KERNEL); + if (!a53cc) + return -ENOMEM; + + /* Use an unique name by appending parent's @unit-address */ + init.name = devm_kasprintf(dev, GFP_KERNEL, "a53mux%s", + strchrnul(np->full_name, '@')); + if (!init.name) + return -ENOMEM; + + init.parent_data = pdata; + init.num_parents = ARRAY_SIZE(pdata); + init.ops = &clk_regmap_mux_div_ops; + init.flags = CLK_IS_CRITICAL | CLK_SET_RATE_PARENT; + + a53cc->clkr.hw.init = &init; + a53cc->clkr.regmap = regmap; + a53cc->reg_offset = 0x50; + a53cc->hid_width = 5; + a53cc->hid_shift = 0; + a53cc->src_width = 3; + a53cc->src_shift = 8; + a53cc->parent_map = gpll0_a53cc_map; + + a53cc->pclk = devm_clk_get(parent, NULL); + if (IS_ERR(a53cc->pclk)) { + ret = PTR_ERR(a53cc->pclk); + if (ret != -EPROBE_DEFER) + dev_err(dev, "failed to get clk: %d\n", ret); + return ret; + } + + a53cc->clk_nb.notifier_call = a53cc_notifier_cb; + ret = clk_notifier_register(a53cc->pclk, &a53cc->clk_nb); + if (ret) { + dev_err(dev, "failed to register clock notifier: %d\n", ret); + return ret; + } + + ret = devm_clk_register_regmap(dev, &a53cc->clkr); + if (ret) { + dev_err(dev, "failed to register regmap clock: %d\n", ret); + goto err; + } + + ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get, + &a53cc->clkr.hw); + if (ret) { + dev_err(dev, "failed to add clock provider: %d\n", ret); + goto err; + } + + platform_set_drvdata(pdev, a53cc); + + return 0; + +err: + clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb); + return ret; +} + +static int qcom_apcs_msm8916_clk_remove(struct platform_device *pdev) +{ + struct clk_regmap_mux_div *a53cc = platform_get_drvdata(pdev); + + clk_notifier_unregister(a53cc->pclk, &a53cc->clk_nb); + + return 0; +} + +static struct platform_driver qcom_apcs_msm8916_clk_driver = { + .probe = qcom_apcs_msm8916_clk_probe, + .remove = qcom_apcs_msm8916_clk_remove, + .driver = { + .name = "qcom-apcs-msm8916-clk", + }, +}; +module_platform_driver(qcom_apcs_msm8916_clk_driver); + +MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>"); +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Qualcomm MSM8916 APCS clock driver"); |