In K2G, the clock handling is done through firmware executing on a separate core. Linux kernel needs to communicate to the firmware through TI system control interface to access any power management related resources, including clocks. The keystone sci-clk driver does this, by communicating to the firmware through the TI SCI driver. The driver adds support for registering clocks through DT, and basic required clock operations like prepare/get_rate, etc. Signed-off-by: Tero Kristo <t-kristo@xxxxxx> --- MAINTAINERS | 1 + drivers/clk/Kconfig | 9 + drivers/clk/keystone/Makefile | 1 + drivers/clk/keystone/sci-clk.c | 537 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 548 insertions(+) create mode 100644 drivers/clk/keystone/sci-clk.c diff --git a/MAINTAINERS b/MAINTAINERS index bcb7b9e..2ed4d38 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11575,6 +11575,7 @@ F: drivers/firmware/ti_sci* F: include/linux/soc/ti/ti_sci_protocol.h F: Documentation/devicetree/bindings/clock/ti,sci-clk.txt F: include/dt-bindings/clock/k2g.h +F: drivers/clk/keystone/sci-clk.c THANKO'S RAREMONO AM/FM/SW RADIO RECEIVER USB DRIVER M: Hans Verkuil <hverkuil@xxxxxxxxx> diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig index e2d9bd7..dbe792a7 100644 --- a/drivers/clk/Kconfig +++ b/drivers/clk/Kconfig @@ -179,6 +179,15 @@ config COMMON_CLK_NXP ---help--- Support for clock providers on NXP platforms. +config TI_SCI_CLK + tristate "TI System Control Interface clock drivers" + depends on (TI_SCI_PROTOCOL && COMMON_CLK_KEYSTONE) || COMPILE_TEST + default TI_SCI_PROTOCOL + ---help--- + This adds the clock driver support over TI System Control Interface. + If you wish to use clock resources from the PMMC firmware, say Y. + Otherwise, say N. + config COMMON_CLK_PALMAS tristate "Clock driver for TI Palmas devices" depends on MFD_PALMAS diff --git a/drivers/clk/keystone/Makefile b/drivers/clk/keystone/Makefile index 0477cf6..0e7993d 100644 --- a/drivers/clk/keystone/Makefile +++ b/drivers/clk/keystone/Makefile @@ -1 +1,2 @@ obj-y += pll.o gate.o +obj-$(CONFIG_TI_SCI_CLK) += sci-clk.o diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c new file mode 100644 index 0000000..852fc49 --- /dev/null +++ b/drivers/clk/keystone/sci-clk.c @@ -0,0 +1,537 @@ +/* + * SCI Clock driver for keystone based devices + * + * Copyright (C) 2015-2016 Texas Instruments Incorporated - http://www.ti.com/ + * Tero Kristo <t-kristo@xxxxxx> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/soc/ti/ti_sci_protocol.h> + +#define SCI_CLK_SSC_ENABLE BIT(0) +#define SCI_CLK_ALLOW_FREQ_CHANGE BIT(1) +#define SCI_CLK_INPUT_TERMINATION BIT(2) + +/** + * struct sci_clk_provider - TI SCI clock provider representation + * @sci: Handle to the System Control Interface protocol handler + * @ops: Pointer to the SCI ops to be used by the clocks + * @dev: Device pointer for the clock provider + * @clocks: List of all registered clocks + * @lock: Mutex for locking access to the @clocks list + */ +struct sci_clk_provider { + const struct ti_sci_handle *sci; + const struct ti_sci_clk_ops *ops; + struct device *dev; + struct list_head clocks; + struct mutex lock; /* Protects access to the @clocks list */ +}; + +/** + * struct sci_clk - TI SCI clock representation + * @hw: Hardware clock cookie for common clock framework + * @dev_id: Device index + * @clk_id: Clock index + * @node: Clocks list link + * @provider: Master clock provider + * @flags: Flags for the clock + */ +struct sci_clk { + struct clk_hw hw; + u16 dev_id; + u8 clk_id; + struct list_head node; + struct sci_clk_provider *provider; + u8 flags; +}; + +#define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw) + +/** + * sci_clk_prepare - Prepare (enable) a TI SCI clock + * @hw: clock to prepare + * + * Prepares a clock to be actively used. Returns the SCI protocol status. + */ +static int sci_clk_prepare(struct clk_hw *hw) +{ + struct sci_clk *clk = to_sci_clk(hw); + bool enable_ssc = clk->flags & SCI_CLK_SSC_ENABLE; + bool allow_freq_change = clk->flags & SCI_CLK_ALLOW_FREQ_CHANGE; + bool input_termination = clk->flags & SCI_CLK_INPUT_TERMINATION; + + return clk->provider->ops->get_clock(clk->provider->sci, clk->dev_id, + clk->clk_id, enable_ssc, + allow_freq_change, + input_termination); +} + +/** + * sci_clk_unprepare - Un-prepares (disables) a TI SCI clock + * @hw: clock to unprepare + * + * Un-prepares a clock from active state. + */ +static void sci_clk_unprepare(struct clk_hw *hw) +{ + struct sci_clk *clk = to_sci_clk(hw); + int ret; + + ret = clk->provider->ops->put_clock(clk->provider->sci, clk->dev_id, + clk->clk_id); + if (ret) + dev_err(clk->provider->dev, + "unprepare failed for dev=%d, clk=%d, ret=%d\n", + clk->dev_id, clk->clk_id, ret); +} + +/** + * sci_clk_is_prepared - Check if a TI SCI clock is prepared or not + * @hw: clock to check status for + * + * Checks if a clock is prepared (enabled) in hardware. Returns non-zero + * value if clock is enabled, zero otherwise. + */ +static int sci_clk_is_prepared(struct clk_hw *hw) +{ + struct sci_clk *clk = to_sci_clk(hw); + bool req_state, current_state; + int ret; + + ret = clk->provider->ops->is_on(clk->provider->sci, clk->dev_id, + clk->clk_id, &req_state, + ¤t_state); + if (ret) { + dev_err(clk->provider->dev, + "is_prepared failed for dev=%d, clk=%d, ret=%d\n", + clk->dev_id, clk->clk_id, ret); + return 0; + } + + return req_state; +} + +/** + * sci_clk_recalc_rate - Get clock rate for a TI SCI clock + * @hw: clock to get rate for + * @parent_rate: parent rate provided by common clock framework, not used + * + * Gets the current clock rate of a TI SCI clock. Returns the current + * clock rate, or zero in failure. + */ +static unsigned long sci_clk_recalc_rate(struct clk_hw *hw, + unsigned long parent_rate) +{ + struct sci_clk *clk = to_sci_clk(hw); + u64 freq; + int ret; + + ret = clk->provider->ops->get_freq(clk->provider->sci, clk->dev_id, + clk->clk_id, &freq); + if (ret) { + dev_err(clk->provider->dev, + "recalc-rate failed for dev=%d, clk=%d, ret=%d\n", + clk->dev_id, clk->clk_id, ret); + return 0; + } + + return (u32)freq; +} + +/** + * sci_clk_determine_rate - Determines a clock rate a clock can be set to + * @hw: clock to change rate for + * @req: requested rate configuration for the clock + * + * Determines a suitable clock rate and parent for a TI SCI clock. + * The parent handling is un-used, as generally the parent clock rates + * are not known by the kernel; instead these are internally handled + * by the firmware. Returns 0 on success, negative error value on failure. + */ +static int sci_clk_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct sci_clk *clk = to_sci_clk(hw); + int ret; + u64 new_rate; + + ret = clk->provider->ops->get_best_match_freq(clk->provider->sci, + clk->dev_id, + clk->clk_id, + req->min_rate, + req->rate, + req->max_rate, + &new_rate); + if (ret) { + dev_err(clk->provider->dev, + "determine-rate failed for dev=%d, clk=%d, ret=%d\n", + clk->dev_id, clk->clk_id, ret); + return ret; + } + + req->rate = new_rate; + + return 0; +} + +/** + * sci_clk_set_rate - Set rate for a TI SCI clock + * @hw: clock to change rate for + * @rate: target rate for the clock + * @parent_rate: rate of the clock parent, not used for TI SCI clocks + * + * Sets a clock frequency for a TI SCI clock. Returns the TI SCI + * protocol status. + */ +static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate, + unsigned long parent_rate) +{ + struct sci_clk *clk = to_sci_clk(hw); + + return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id, + clk->clk_id, rate, rate, rate); +} + +/** + * sci_clk_get_parent - Get the current parent of a TI SCI clock + * @hw: clock to get parent for + * + * Returns the index of the currently selected parent for a TI SCI clock. + */ +static u8 sci_clk_get_parent(struct clk_hw *hw) +{ + struct sci_clk *clk = to_sci_clk(hw); + u8 parent_id; + int ret; + + ret = clk->provider->ops->get_parent(clk->provider->sci, clk->dev_id, + clk->clk_id, &parent_id); + if (ret) { + dev_err(clk->provider->dev, + "get-parent failed for dev=%d, clk=%d, ret=%d\n", + clk->dev_id, clk->clk_id, ret); + return 0; + } + + return parent_id - clk->clk_id - 1; +} + +/** + * sci_clk_set_parent - Set the parent of a TI SCI clock + * @hw: clock to set parent for + * @index: new parent index for the clock + * + * Sets the parent of a TI SCI clock. Return TI SCI protocol status. + */ +static int sci_clk_set_parent(struct clk_hw *hw, u8 index) +{ + struct sci_clk *clk = to_sci_clk(hw); + + return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id, + clk->clk_id, + index + 1 + clk->clk_id); +} + +static const struct clk_ops sci_clk_ops = { + .prepare = sci_clk_prepare, + .unprepare = sci_clk_unprepare, + .is_prepared = sci_clk_is_prepared, + .recalc_rate = sci_clk_recalc_rate, + .determine_rate = sci_clk_determine_rate, + .set_rate = sci_clk_set_rate, + .get_parent = sci_clk_get_parent, + .set_parent = sci_clk_set_parent, +}; + +/** + * _sci_clk_get - Gets a handle for an SCI clock + * @provider: Handle to SCI clock provider + * @dev_id: device ID for the clock to register + * @clk_id: clock ID for the clock to register + * @parse_parents: indicator whether parents for this clock should be handled + * + * Gets a handle to an existing TI SCI hw clock, or builds a new clock + * entry and registers it with the common clock framework. Called from + * the common clock framework, when a corresponding of_clk_get call is + * executed, or recursively from itself when parsing parent clocks. + * Returns a pointer to the hw clock struct, or ERR_PTR value in failure. + */ +static struct clk_hw *_sci_clk_get(struct sci_clk_provider *provider, + u16 dev_id, u8 clk_id, bool parse_parents) +{ + struct clk_init_data init = { NULL }; + struct sci_clk *sci_clk = NULL; + char *name = NULL; + char **parent_names = NULL; + int i; + int ret; + + list_for_each_entry(sci_clk, &provider->clocks, node) + if (sci_clk->dev_id == dev_id && sci_clk->clk_id == clk_id) + return &sci_clk->hw; + + sci_clk = devm_kzalloc(provider->dev, sizeof(*sci_clk), GFP_KERNEL); + if (!sci_clk) { + ret = -ENOMEM; + goto err; + } + + sci_clk->dev_id = dev_id; + sci_clk->clk_id = clk_id; + sci_clk->provider = provider; + + if (parse_parents) { + ret = provider->ops->get_num_parents(provider->sci, dev_id, + clk_id, + &init.num_parents); + if (ret) + goto err; + } + + name = kasprintf(GFP_KERNEL, "%s:%d:%d", dev_name(provider->dev), + sci_clk->dev_id, sci_clk->clk_id); + + init.name = name; + + if (init.num_parents < 2) + init.num_parents = 0; + + if (init.num_parents) { + parent_names = devm_kcalloc(provider->dev, init.num_parents, + sizeof(char *), GFP_KERNEL); + + if (!parent_names) { + ret = -ENOMEM; + goto err; + } + + for (i = 0; i < init.num_parents; i++) { + char *parent_name; + + parent_name = devm_kzalloc(provider->dev, 20, + GFP_KERNEL); + if (!parent_name) { + ret = -ENOMEM; + goto err; + } + snprintf(parent_name, 20, "%s:%d:%d", + dev_name(provider->dev), sci_clk->dev_id, + sci_clk->clk_id + 1 + i); + parent_names[i] = parent_name; + + _sci_clk_get(provider, dev_id, clk_id + 1 + i, false); + } + init.parent_names = (const char * const *)parent_names; + } + + init.ops = &sci_clk_ops; + sci_clk->hw.init = &init; + + ret = devm_clk_hw_register(provider->dev, &sci_clk->hw); + if (ret) { + dev_err(provider->dev, "failed clk register with %d\n", ret); + goto err; + } else { + list_add(&sci_clk->node, &provider->clocks); + } + + kfree(name); + + return &sci_clk->hw; + +err: + if (parent_names) { + for (i = 0; i < init.num_parents; i++) + devm_kfree(provider->dev, parent_names[i]); + + devm_kfree(provider->dev, parent_names); + } + + devm_kfree(provider->dev, sci_clk); + + kfree(name); + + return ERR_PTR(ret); +} + +/** + * sci_clk_get - Xlate function for getting clock handles + * @clkspec: device tree clock specifier + * @data: pointer to the clock provider + * + * Xlate function for retrieving clock TI SCI hw clock handles based on + * device tree clock specifier. Called from the common clock framework, + * when a corresponding of_clk_get call is executed. Returns a pointer + * to the TI SCI hw clock struct, or ERR_PTR value in failure. + */ +static struct clk_hw *sci_clk_get(struct of_phandle_args *clkspec, void *data) +{ + struct sci_clk_provider *provider = data; + struct clk_hw *clk; + u16 dev_id; + u8 clk_id; + + if (clkspec->args_count != 2) + return ERR_PTR(-EINVAL); + + mutex_lock(&provider->lock); + + dev_id = clkspec->args[0]; + clk_id = clkspec->args[1]; + + clk = _sci_clk_get(provider, dev_id, clk_id, true); + + mutex_unlock(&provider->lock); + + return clk; +} + +static const struct of_device_id ti_sci_clk_of_match[] = { + { .compatible = "ti,sci-clk" }, + { /* Sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, ti_sci_clk_of_match); + +/** + * ti_sci_clk_parse_flags - Helper function to parse clock flag arrays + * @provider: clock provider handle + * @list_name: property name containing the clocks list + * @flag: flag to apply to the list of clocks + * + * Parses a DT list based on the provided data, and applies the flag value + * for each of the clocks identified by the list. Return 0 for success, + * negative error value for failure. + */ +static int ti_sci_clk_parse_flags(struct sci_clk_provider *provider, + const char *list_name, u8 flag) +{ + int num_clks; + int i; + struct device_node *np = provider->dev->of_node; + struct device *dev = provider->dev; + + num_clks = of_count_phandle_with_args(np, list_name, "#clock-cells"); + + for (i = 0; i < num_clks; i++) { + struct of_phandle_args clkspec; + struct sci_clk *sci_clk; + struct clk_hw *clk; + int ret; + + ret = of_parse_phandle_with_args(np, list_name, "#clock-cells", + i, &clkspec); + if (ret) { + dev_err(dev, "Failed to parse %s[%d] = %d\n", list_name, + i, ret); + return ret; + } + clk = sci_clk_get(&clkspec, provider); + if (IS_ERR(clk)) { + dev_err(dev, "clk_get failed for %s[%d] = %ld\n", + list_name, i, PTR_ERR(clk)); + return PTR_ERR(clk); + } + sci_clk = to_sci_clk(clk); + + sci_clk->flags |= flag; + } + + return 0; +} + +/** + * ti_sci_clk_probe - Probe function for the TI SCI clock driver + * @pdev: platform device pointer to be probed + * + * Probes the TI SCI clock device. Allocates a new clock provider + * and registers this to the common clock framework. Also applies + * any required flags to the identified clocks via clock lists + * supplied from DT. Returns 0 for success, negative error value + * for failure. + */ +static int ti_sci_clk_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct device_node *np = dev->of_node; + struct sci_clk_provider *provider; + const struct ti_sci_handle *handle; + int ret; + + if (!np) { + dev_err(dev, "OF data missing\n"); + return -EINVAL; + } + + handle = devm_ti_sci_get_handle(dev); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + provider = devm_kzalloc(dev, sizeof(*provider), GFP_KERNEL); + if (!provider) + return -ENOMEM; + + INIT_LIST_HEAD(&provider->clocks); + mutex_init(&provider->lock); + + provider->sci = handle; + provider->ops = &handle->ops.clk_ops; + provider->dev = dev; + + ret = of_clk_add_hw_provider(np, sci_clk_get, provider); + if (ret) + return ret; + + ti_sci_clk_parse_flags(provider, "ti,ssc-clocks", SCI_CLK_SSC_ENABLE); + ti_sci_clk_parse_flags(provider, "ti,allow-freq-change-clocks", + SCI_CLK_ALLOW_FREQ_CHANGE); + ti_sci_clk_parse_flags(provider, "ti,input-term-clocks", + SCI_CLK_INPUT_TERMINATION); + + return 0; +} + +/** + * ti_sci_clk_remove - Remove TI SCI clock device + * @pdev: platform device pointer for the device to be removed + * + * Removes the TI SCI device. Unregisters the clock provider registered + * via common clock framework. Any memory allocated for the device will + * be free'd silently via the devm framework. Returns 0 always. + */ +static int ti_sci_clk_remove(struct platform_device *pdev) +{ + of_clk_del_provider(pdev->dev.of_node); + + return 0; +} + +static struct platform_driver ti_sci_clk_driver = { + .probe = ti_sci_clk_probe, + .remove = ti_sci_clk_remove, + .driver = { + .name = "ti-sci-clk", + .of_match_table = of_match_ptr(ti_sci_clk_of_match), + }, +}; +module_platform_driver(ti_sci_clk_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("TI System Control Interface(SCI) Clock driver"); +MODULE_AUTHOR("Tero Kristo"); +MODULE_ALIAS("platform:ti-sci-clk"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
