TI's AM62 SoC can optionally provide two audio reference clocks (AUDIO_REFCLKx) to external peripherals. By default this reference clock is looped-back inside the SoC to a mux that goes to McASP AHCLK, but can optionally be enabled as an output to peripherals outside the SoC by setting a bit through CTRL_MMR registers. This bit only controls the direction of the clock, while the parent is a muxed input from sci-clk [1] which may be a configurable PLL or a master clock from one of the McASP instances. Link: http://downloads.ti.com/tisci/esd/latest/5_soc_doc/am62x/clocks.html#clocks-for-board0-device [1] Signed-off-by: Jai Luthra <j-luthra@xxxxxx> --- drivers/clk/keystone/syscon-clk.c | 45 ++++++++++++++++++++++++++++++++++----- 1 file changed, 40 insertions(+), 5 deletions(-) diff --git a/drivers/clk/keystone/syscon-clk.c b/drivers/clk/keystone/syscon-clk.c index bd5cec0bd12d..d33f74119488 100644 --- a/drivers/clk/keystone/syscon-clk.c +++ b/drivers/clk/keystone/syscon-clk.c @@ -4,10 +4,12 @@ */ #include <linux/clk-provider.h> +#include <linux/kernel.h> #include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/regmap.h> +#include <linux/slab.h> struct ti_syscon_gate_clk_priv { struct clk_hw hw; @@ -61,21 +63,31 @@ static const struct clk_ops ti_syscon_gate_clk_ops = { static struct clk_hw *ti_syscon_gate_clk_register(struct device *dev, struct regmap *regmap, + const char *parent_name, const struct ti_syscon_gate_clk_data *data) { struct ti_syscon_gate_clk_priv *priv; struct clk_init_data init; + char *name = NULL; int ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); if (!priv) return ERR_PTR(-ENOMEM); - init.name = data->name; init.ops = &ti_syscon_gate_clk_ops; - init.parent_names = NULL; - init.num_parents = 0; - init.flags = 0; + if (parent_name) { + name = kasprintf(GFP_KERNEL, "%s:%s", data->name, parent_name); + init.name = name; + init.parent_names = &parent_name; + init.num_parents = 1; + init.flags = CLK_SET_RATE_PARENT; + } else { + init.name = data->name; + init.parent_names = NULL; + init.num_parents = 0; + init.flags = 0; + } priv->regmap = regmap; priv->reg = data->offset; @@ -83,6 +95,10 @@ static struct clk_hw priv->hw.init = &init; ret = devm_clk_hw_register(dev, &priv->hw); + + if (name) + kfree(init.name); + if (ret) return ERR_PTR(ret); @@ -94,8 +110,9 @@ static int ti_syscon_gate_clk_probe(struct platform_device *pdev) const struct ti_syscon_gate_clk_data *data, *p; struct clk_hw_onecell_data *hw_data; struct device *dev = &pdev->dev; + int num_clks, num_parents, i; + const char *parent_name; struct regmap *regmap; - int num_clks, i; data = device_get_match_data(dev); if (!data) @@ -110,6 +127,13 @@ static int ti_syscon_gate_clk_probe(struct platform_device *pdev) for (p = data; p->name; p++) num_clks++; + num_parents = of_clk_get_parent_count(dev->of_node); + if (of_device_is_compatible(dev->of_node, "ti,am62-audio-refclk") && + num_parents == 0) { + return dev_err_probe(dev, -EINVAL, + "must specify a parent clock\n"); + } + hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, num_clks), GFP_KERNEL); if (!hw_data) @@ -117,8 +141,10 @@ static int ti_syscon_gate_clk_probe(struct platform_device *pdev) hw_data->num = num_clks; + parent_name = of_clk_get_parent_name(dev->of_node, 0); for (i = 0; i < num_clks; i++) { hw_data->hws[i] = ti_syscon_gate_clk_register(dev, regmap, + parent_name, &data[i]); if (IS_ERR(hw_data->hws[i])) dev_warn(dev, "failed to register %s\n", @@ -166,6 +192,11 @@ static const struct ti_syscon_gate_clk_data am62_clk_data[] = { { /* Sentinel */ }, }; +static const struct ti_syscon_gate_clk_data am62_audio_clk_data[] = { + TI_SYSCON_CLK_GATE("audio_refclk", 0x0, 15), + { /* Sentinel */ }, +}; + static const struct of_device_id ti_syscon_gate_clk_ids[] = { { .compatible = "ti,am654-ehrpwm-tbclk", @@ -179,6 +210,10 @@ static const struct of_device_id ti_syscon_gate_clk_ids[] = { .compatible = "ti,am62-epwm-tbclk", .data = &am62_clk_data, }, + { + .compatible = "ti,am62-audio-refclk", + .data = &am62_audio_clk_data, + }, { } }; MODULE_DEVICE_TABLE(of, ti_syscon_gate_clk_ids); -- 2.41.0
