diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | drivers/clk/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/clk/Makefile | 1 | ||||
| -rw-r--r-- | drivers/clk/clk-scpi.c | 312 |
4 files changed, 324 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 9598821d6a37..613a116ab0f4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9154,6 +9154,7 @@ M: Sudeep Holla <sudeep.holla@arm.com> L: linux-arm-kernel@lists.infradead.org S: Maintained F: Documentation/devicetree/bindings/arm/arm,scpi.txt +F: drivers/clk/clk-scpi.c F: drivers/firmware/arm_scpi.c F: include/linux/scpi_protocol.h diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index 42f7120ca9ce..4aec54b90331 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -59,6 +59,16 @@ config COMMON_CLK_RK808 clocked at 32KHz each. Clkout1 is always on, Clkout2 can off by control register. +config COMMON_CLK_SCPI + tristate "Clock driver controlled via SCPI interface" + depends on ARM_SCPI_PROTOCOL || COMPILE_TEST + ---help--- + This driver provides support for clocks that are controlled + by firmware that implements the SCPI interface. + + This driver uses SCPI Message Protocol to interact with the + firmware providing all the clock controls. + config COMMON_CLK_SI5351 tristate "Clock driver for SiLabs 5351A/B/C" depends on I2C diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index d08b3e5985be..a381431bd950 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -36,6 +36,7 @@ obj-$(CONFIG_COMMON_CLK_PALMAS) += clk-palmas.o obj-$(CONFIG_CLK_QORIQ) += clk-qoriq.o obj-$(CONFIG_COMMON_CLK_RK808) += clk-rk808.o obj-$(CONFIG_COMMON_CLK_S2MPS11) += clk-s2mps11.o +obj-$(CONFIG_COMMON_CLK_SCPI) += clk-scpi.o obj-$(CONFIG_COMMON_CLK_SI5351) += clk-si5351.o obj-$(CONFIG_COMMON_CLK_SI570) += clk-si570.o obj-$(CONFIG_COMMON_CLK_CDCE925) += clk-cdce925.o diff --git a/drivers/clk/clk-scpi.c b/drivers/clk/clk-scpi.c new file mode 100644 index 000000000000..72f0486b5de6 --- /dev/null +++ b/drivers/clk/clk-scpi.c @@ -0,0 +1,312 @@ +/* + * System Control and Power Interface (SCPI) Protocol based clock driver + * + * Copyright (C) 2015 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/clk-provider.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/of.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/scpi_protocol.h> + +struct scpi_clk { + u32 id; + struct clk_hw hw; + struct scpi_dvfs_info *info; + struct scpi_ops *scpi_ops; +}; + +#define to_scpi_clk(clk) container_of(clk, struct scpi_clk, hw) + +static unsigned long scpi_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct scpi_clk *clk = to_scpi_clk(hw); + + return clk->scpi_ops->clk_get_val(clk->id); +} + +static long scpi_clk_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + /* + * We can't figure out what rate it will be, so just return the + * rate back to the caller. scpi_clk_recalc_rate() will be called + * after the rate is set and we'll know what rate the clock is + * running at then. + */ + return rate; +} + +static int scpi_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct scpi_clk *clk = to_scpi_clk(hw); + + return clk->scpi_ops->clk_set_val(clk->id, rate); +} + +static const struct clk_ops scpi_clk_ops = { + .recalc_rate = scpi_clk_recalc_rate, + .round_rate = scpi_clk_round_rate, + .set_rate = scpi_clk_set_rate, +}; + +/* find closest match to given frequency in OPP table */ +static int __scpi_dvfs_round_rate(struct scpi_clk *clk, unsigned long rate) +{ + int idx; + u32 fmin = 0, fmax = ~0, ftmp; + const struct scpi_opp *opp = clk->info->opps; + + for (idx = 0; idx < clk->info->count; idx++, opp++) { + ftmp = opp->freq; + if (ftmp >= (u32)rate) { + if (ftmp <= fmax) + fmax = ftmp; + break; + } else if (ftmp >= fmin) { + fmin = ftmp; + } + } + return fmax != ~0 ? fmax : fmin; +} + +static unsigned long scpi_dvfs_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct scpi_clk *clk = to_scpi_clk(hw); + int idx = clk->scpi_ops->dvfs_get_idx(clk->id); + const struct scpi_opp *opp; + + if (idx < 0) + return 0; + + opp = clk->info->opps + idx; + return opp->freq; +} + +static long scpi_dvfs_round_rate(struct clk_hw *hw, unsigned long rate, + unsigned long *parent_rate) +{ + struct scpi_clk *clk = to_scpi_clk(hw); + + return __scpi_dvfs_round_rate(clk, rate); +} + +static int __scpi_find_dvfs_index(struct scpi_clk *clk, unsigned long rate) +{ + int idx, max_opp = clk->info->count; + const struct scpi_opp *opp = clk->info->opps; + + for (idx = 0; idx < max_opp; idx++, opp++) + if (opp->freq == rate) + return idx; + return -EINVAL; +} + +static int scpi_dvfs_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct scpi_clk *clk = to_scpi_clk(hw); + int ret = __scpi_find_dvfs_index(clk, rate); + + if (ret < 0) + return ret; + return clk->scpi_ops->dvfs_set_idx(clk->id, (u8)ret); +} + +static const struct clk_ops scpi_dvfs_ops = { + .recalc_rate = scpi_dvfs_recalc_rate, + .round_rate = scpi_dvfs_round_rate, + .set_rate = scpi_dvfs_set_rate, +}; + +static const struct of_device_id scpi_clk_match[] = { + { .compatible = "arm,scpi-dvfs-clocks", .data = &scpi_dvfs_ops, }, + { .compatible = "arm,scpi-variable-clocks", .data = &scpi_clk_ops, }, + {} +}; + +static struct clk * +scpi_clk_ops_init(struct device *dev, const struct of_device_id *match, + struct scpi_clk *sclk, const char *name) +{ + struct clk_init_data init; + struct clk *clk; + unsigned long min = 0, max = 0; + + init.name = name; + init.flags = CLK_IS_ROOT; + init.num_parents = 0; + init.ops = match->data; + sclk->hw.init = &init; + sclk->scpi_ops = get_scpi_ops(); + + if (init.ops == &scpi_dvfs_ops) { + sclk->info = sclk->scpi_ops->dvfs_get_info(sclk->id); + if (IS_ERR(sclk->info)) + return NULL; + } else if (init.ops == &scpi_clk_ops) { + if (sclk->scpi_ops->clk_get_range(sclk->id, &min, &max) || !max) + return NULL; + } else { + return NULL; + } + + clk = devm_clk_register(dev, &sclk->hw); + if (!IS_ERR(clk) && max) + clk_hw_set_rate_range(&sclk->hw, min, max); + return clk; +} + +struct scpi_clk_data { + struct scpi_clk **clk; + unsigned int clk_num; +}; + +static struct clk * +scpi_of_clk_src_get(struct of_phandle_args *clkspec, void *data) +{ + struct scpi_clk *sclk; + struct scpi_clk_data *clk_data = data; + unsigned int idx = clkspec->args[0], count; + + for (count = 0; count < clk_data->clk_num; count++) { + sclk = clk_data->clk[count]; + if (idx == sclk->id) + return sclk->hw.clk; + } + + return ERR_PTR(-EINVAL); +} + +static int scpi_clk_add(struct device *dev, struct device_node *np, + const struct of_device_id *match) +{ + struct clk **clks; + int idx, count; + struct scpi_clk_data *clk_data; + + count = of_property_count_strings(np, "clock-output-names"); + if (count < 0) { + dev_err(dev, "%s: invalid clock output count\n", np->name); + return -EINVAL; + } + + clk_data = devm_kmalloc(dev, sizeof(*clk_data), GFP_KERNEL); + if (!clk_data) + return -ENOMEM; + + clk_data->clk_num = count; + clk_data->clk = devm_kcalloc(dev, count, sizeof(*clk_data->clk), + GFP_KERNEL); + if (!clk_data->clk) + return -ENOMEM; + + clks = devm_kcalloc(dev, count, sizeof(*clks), GFP_KERNEL); + if (!clks) + return -ENOMEM; + + for (idx = 0; idx < count; idx++) { + struct scpi_clk *sclk; + const char *name; + u32 val; + + sclk = devm_kzalloc(dev, sizeof(*sclk), GFP_KERNEL); + if (!sclk) + return -ENOMEM; + + if (of_property_read_string_index(np, "clock-output-names", + idx, &name)) { + dev_err(dev, "invalid clock name @ %s\n", np->name); + return -EINVAL; + } + + if (of_property_read_u32_index(np, "clock-indices", + idx, &val)) { + dev_err(dev, "invalid clock index @ %s\n", np->name); + return -EINVAL; + } + + sclk->id = val; + + clks[idx] = scpi_clk_ops_init(dev, match, sclk, name); + if (IS_ERR_OR_NULL(clks[idx])) + dev_err(dev, "failed to register clock '%s'\n", name); + else + dev_dbg(dev, "Registered clock '%s'\n", name); + clk_data->clk[idx] = sclk; + } + + return of_clk_add_provider(np, scpi_of_clk_src_get, clk_data); +} + +static int scpi_clocks_remove(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *child, *np = dev->of_node; + + for_each_available_child_of_node(np, child) + of_clk_del_provider(np); + return 0; +} + +static int scpi_clocks_probe(struct platform_device *pdev) +{ + int ret; + struct device *dev = &pdev->dev; + struct device_node *child, *np = dev->of_node; + const struct of_device_id *match; + + if (!get_scpi_ops()) + return -ENXIO; + + for_each_available_child_of_node(np, child) { + match = of_match_node(scpi_clk_match, child); + if (!match) + continue; + ret = scpi_clk_add(dev, child, match); + if (ret) { + scpi_clocks_remove(pdev); + return ret; + } + } + return 0; +} + +static const struct of_device_id scpi_clocks_ids[] = { + { .compatible = "arm,scpi-clocks", }, + {} +}; +MODULE_DEVICE_TABLE(of, scpi_clocks_ids); + +static struct platform_driver scpi_clocks_driver = { + .driver = { + .name = "scpi_clocks", + .of_match_table = scpi_clocks_ids, + }, + .probe = scpi_clocks_probe, + .remove = scpi_clocks_remove, +}; +module_platform_driver(scpi_clocks_driver); + +MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); +MODULE_DESCRIPTION("ARM SCPI clock driver"); +MODULE_LICENSE("GPL v2"); |