Add a driver for the Xilinx Clocking Wizard soft IP. The clocking wizard provides an AXI interface to dynamically reconfigure the clocking resources of Xilinx FPGAs.
Signed-off-by: Soren Brinkmann <soren.brinkm...@xilinx.com> --- v3: - allow building the driver as module - make speed grade positive - document valid values for speed-grade DT property v2: - implement dev_pm_ops - don't use array for clock inputs - add more information in error output - fix style issues - fix error path --- drivers/staging/Kconfig | 2 + drivers/staging/Makefile | 1 + drivers/staging/clocking-wizard/Kconfig | 9 + drivers/staging/clocking-wizard/Makefile | 1 + drivers/staging/clocking-wizard/TODO | 12 + .../clocking-wizard/clk-xlnx-clock-wizard.c | 335 +++++++++++++++++++++ drivers/staging/clocking-wizard/dt-binding.txt | 30 ++ 7 files changed, 390 insertions(+) create mode 100644 drivers/staging/clocking-wizard/Kconfig create mode 100644 drivers/staging/clocking-wizard/Makefile create mode 100644 drivers/staging/clocking-wizard/TODO create mode 100644 drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c create mode 100644 drivers/staging/clocking-wizard/dt-binding.txt diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig index 35b494f5667f..7daf345bec0e 100644 --- a/drivers/staging/Kconfig +++ b/drivers/staging/Kconfig @@ -118,4 +118,6 @@ source "drivers/staging/skein/Kconfig" source "drivers/staging/unisys/Kconfig" +source "drivers/staging/clocking-wizard/Kconfig" + endif # STAGING diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile index e66a5dbd9b02..03fec7f981cc 100644 --- a/drivers/staging/Makefile +++ b/drivers/staging/Makefile @@ -51,3 +51,4 @@ obj-$(CONFIG_GS_FPGABOOT) += gs_fpgaboot/ obj-$(CONFIG_BT_NOKIA_H4P) += nokia_h4p/ obj-$(CONFIG_CRYPTO_SKEIN) += skein/ obj-$(CONFIG_UNISYSSPAR) += unisys/ +obj-$(CONFIG_COMMON_CLK_XLNX_CLKWZRD) += clocking-wizard/ diff --git a/drivers/staging/clocking-wizard/Kconfig b/drivers/staging/clocking-wizard/Kconfig new file mode 100644 index 000000000000..357af02c562c --- /dev/null +++ b/drivers/staging/clocking-wizard/Kconfig @@ -0,0 +1,9 @@ +# +# Xilinx Clocking Wizard Driver +# + +config COMMON_CLK_XLNX_CLKWZRD + tristate "Xilinx Clocking Wizard" + depends on COMMON_CLK && OF + ---help--- + Support for the Xilinx Clocking Wizard IP core clock generator. diff --git a/drivers/staging/clocking-wizard/Makefile b/drivers/staging/clocking-wizard/Makefile new file mode 100644 index 000000000000..5ad352f521fe --- /dev/null +++ b/drivers/staging/clocking-wizard/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_COMMON_CLK_XLNX_CLKWZRD) += clk-xlnx-clock-wizard.o diff --git a/drivers/staging/clocking-wizard/TODO b/drivers/staging/clocking-wizard/TODO new file mode 100644 index 000000000000..ebe99db7d153 --- /dev/null +++ b/drivers/staging/clocking-wizard/TODO @@ -0,0 +1,12 @@ +TODO: + - support for fractional multiplier + - support for fractional divider (output 0 only) + - support for set_rate() operations (may benefit from Stephen Boyd's + refactoring of the clk primitives: https://lkml.org/lkml/2014/9/5/766) + - review arithmetic + - overflow after multiplication? + - maximize accuracy before divisions + +Patches to: + Greg Kroah-Hartman <gre...@linuxfoundation.org> + Sören Brinkmann <soren.brinkm...@xilinx.com> diff --git a/drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c b/drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c new file mode 100644 index 000000000000..b8d89525bffd --- /dev/null +++ b/drivers/staging/clocking-wizard/clk-xlnx-clock-wizard.c @@ -0,0 +1,335 @@ +/* + * Xilinx 'Clocking Wizard' driver + * + * Copyright (C) 2013 - 2014 Xilinx + * + * Sören Brinkmann <soren.brinkm...@xilinx.com> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License v2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that 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/platform_device.h> +#include <linux/clk-provider.h> +#include <linux/slab.h> +#include <linux/io.h> +#include <linux/of.h> +#include <linux/module.h> +#include <linux/err.h> + +#define WZRD_NUM_OUTPUTS 7 +#define WZRD_ACLK_MAX_FREQ 250000000UL + +#define WZRD_CLK_CFG_REG(n) (0x200 + 4 * n) + +#define WZRD_CLkOUT0_FRAC_EN BIT(18) +#define WZRD_CLkFBOUT_FRAC_EN BIT(26) + +#define WZRD_CLKFBOUT_MULT_SHIFT 8 +#define WZRD_CLKFBOUT_MULT_MASK (0xff << WZRD_CLKFBOUT_MULT_SHIFT) +#define WZRD_DIVCLK_DIVIDE_SHIFT 0 +#define WZRD_DIVCLK_DIVIDE_MASK (0xff << WZRD_DIVCLK_DIVIDE_SHIFT) +#define WZRD_CLKOUT_DIVIDE_SHIFT 0 +#define WZRD_CLKOUT_DIVIDE_MASK (0xff << WZRD_DIVCLK_DIVIDE_SHIFT) + +enum clk_wzrd_int_clks { + wzrd_clk_mul, + wzrd_clk_mul_div, + wzrd_clk_int_max +}; + +/** + * struct clk_wzrd: + * @clk_data: Clock data + * @nb: Notifier block + * @base: Memory base + * @clk_in1: Handle to input clock 'clk_in1' + * @axi_clk: Handle to input clock 's_axi_aclk' + * @clks_internal: Internal clocks + * @clkout: Output clocks + * @speed_grade: Speed grade of the device + * @suspended: Flag indicating power state of the device + */ +struct clk_wzrd { + struct clk_onecell_data clk_data; + struct notifier_block nb; + void __iomem *base; + struct clk *clk_in1; + struct clk *axi_clk; + struct clk *clks_internal[wzrd_clk_int_max]; + struct clk *clkout[WZRD_NUM_OUTPUTS]; + int speed_grade; + bool suspended; +}; +#define to_clk_wzrd(_nb) container_of(_nb, struct clk_wzrd, nb) + +/* maximum frequencies for input/output clocks per speed grade */ +static const unsigned long clk_wzrd_max_freq[] = { + 800000000UL, + 933000000UL, + 1066000000UL +}; + +static int clk_wzrd_clk_notifier(struct notifier_block *nb, unsigned long event, + void *data) +{ + unsigned long max; + struct clk_notifier_data *ndata = data; + struct clk_wzrd *clk_wzrd = to_clk_wzrd(nb); + + if (clk_wzrd->suspended) + return NOTIFY_OK; + + if (ndata->clk == clk_wzrd->clk_in1) + max = clk_wzrd_max_freq[clk_wzrd->speed_grade - 1]; + if (ndata->clk == clk_wzrd->axi_clk) + max = WZRD_ACLK_MAX_FREQ; + + switch (event) { + case PRE_RATE_CHANGE: + if (ndata->new_rate > max) + return NOTIFY_BAD; + return NOTIFY_OK; + case POST_RATE_CHANGE: + case ABORT_RATE_CHANGE: + default: + return NOTIFY_DONE; + } +} + +static int __maybe_unused clk_wzrd_suspend(struct device *dev) +{ + struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev); + + clk_disable_unprepare(clk_wzrd->axi_clk); + clk_wzrd->suspended = true; + + return 0; +} + +static int __maybe_unused clk_wzrd_resume(struct device *dev) +{ + int ret; + struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev); + + ret = clk_prepare_enable(clk_wzrd->axi_clk); + if (ret) { + dev_err(dev, "unable to enable s_axi_aclk\n"); + return ret; + } + + clk_wzrd->suspended = false; + + return 0; +} + +static SIMPLE_DEV_PM_OPS(clk_wzrd_dev_pm_ops, clk_wzrd_suspend, + clk_wzrd_resume); + +static int clk_wzrd_probe(struct platform_device *pdev) +{ + int i, ret; + u32 reg; + unsigned long rate; + const char *clk_name; + struct clk_wzrd *clk_wzrd; + struct resource *mem; + struct device_node *np = pdev->dev.of_node; + + clk_wzrd = devm_kzalloc(&pdev->dev, sizeof(*clk_wzrd), GFP_KERNEL); + if (!clk_wzrd) + return -ENOMEM; + platform_set_drvdata(pdev, clk_wzrd); + + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); + clk_wzrd->base = devm_ioremap_resource(&pdev->dev, mem); + if (IS_ERR(clk_wzrd->base)) + return PTR_ERR(clk_wzrd->base); + + ret = of_property_read_u32(np, "speed-grade", &clk_wzrd->speed_grade); + if (!ret) { + if (clk_wzrd->speed_grade < 1 || clk_wzrd->speed_grade > 3) { + dev_warn(&pdev->dev, "invalid speed grade '%d'\n", + clk_wzrd->speed_grade); + clk_wzrd->speed_grade = 0; + } + } + + clk_wzrd->clk_in1 = devm_clk_get(&pdev->dev, "clk_in1"); + if (IS_ERR(clk_wzrd->clk_in1)) { + if (clk_wzrd->clk_in1 != ERR_PTR(-EPROBE_DEFER)) + dev_err(&pdev->dev, "clk_in1 not found\n"); + return PTR_ERR(clk_wzrd->clk_in1); + } + + clk_wzrd->axi_clk = devm_clk_get(&pdev->dev, "s_axi_aclk"); + if (IS_ERR(clk_wzrd->axi_clk)) { + if (clk_wzrd->axi_clk != ERR_PTR(-EPROBE_DEFER)) + dev_err(&pdev->dev, "s_axi_aclk not found\n"); + return PTR_ERR(clk_wzrd->axi_clk); + } + ret = clk_prepare_enable(clk_wzrd->axi_clk); + if (ret) { + dev_err(&pdev->dev, "enabling s_axi_aclk failed\n"); + return ret; + } + rate = clk_get_rate(clk_wzrd->axi_clk); + if (rate > WZRD_ACLK_MAX_FREQ) { + dev_err(&pdev->dev, "s_axi_aclk frequency (%lu) too high\n", + rate); + ret = -EINVAL; + goto err_disable_clk; + } + + /* we don't support fractional div/mul yet */ + reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) & + WZRD_CLkFBOUT_FRAC_EN; + reg |= readl(clk_wzrd->base + WZRD_CLK_CFG_REG(2)) & + WZRD_CLkOUT0_FRAC_EN; + if (reg) + dev_warn(&pdev->dev, "fractional div/mul not supported\n"); + + /* register multiplier */ + reg = (readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) & + WZRD_CLKFBOUT_MULT_MASK) >> WZRD_CLKFBOUT_MULT_SHIFT; + clk_name = kasprintf(GFP_KERNEL, "%s_mul", dev_name(&pdev->dev)); + if (!clk_name) { + ret = -ENOMEM; + goto err_disable_clk; + } + clk_wzrd->clks_internal[wzrd_clk_mul] = clk_register_fixed_factor( + &pdev->dev, clk_name, + __clk_get_name(clk_wzrd->clk_in1), + 0, reg, 1); + kfree(clk_name); + if (IS_ERR(clk_wzrd->clks_internal[wzrd_clk_mul])) { + dev_err(&pdev->dev, "unable to register fixed-factor clock\n"); + ret = PTR_ERR(clk_wzrd->clks_internal[wzrd_clk_mul]); + goto err_disable_clk; + } + + /* register div */ + reg = (readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) & + WZRD_DIVCLK_DIVIDE_MASK) >> WZRD_DIVCLK_DIVIDE_SHIFT; + clk_name = kasprintf(GFP_KERNEL, "%s_mul_div", dev_name(&pdev->dev)); + clk_wzrd->clks_internal[wzrd_clk_mul_div] = clk_register_fixed_factor( + &pdev->dev, clk_name, + __clk_get_name(clk_wzrd->clks_internal[wzrd_clk_mul]), + 0, 1, reg); + if (IS_ERR(clk_wzrd->clks_internal[wzrd_clk_mul_div])) { + dev_err(&pdev->dev, "unable to register divider clock\n"); + ret = PTR_ERR(clk_wzrd->clks_internal[wzrd_clk_mul_div]); + goto err_rm_int_clk; + } + + /* register div per output */ + for (i = WZRD_NUM_OUTPUTS - 1; i >= 0 ; i--) { + const char *clkout_name; + if (of_property_read_string_index(np, "clock-output-names", i, + &clkout_name)) { + dev_err(&pdev->dev, + "clock output name not specified\n"); + ret = -EINVAL; + goto err_rm_int_clks; + } + reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(2) + i * 12); + reg &= WZRD_CLKOUT_DIVIDE_MASK; + reg >>= WZRD_CLKOUT_DIVIDE_SHIFT; + clk_wzrd->clkout[i] = clk_register_fixed_factor(&pdev->dev, + clkout_name, clk_name, 0, 1, reg); + if (IS_ERR(clk_wzrd->clkout[i])) { + int j; + for (j = i + 1; j < WZRD_NUM_OUTPUTS; j++) + clk_unregister(clk_wzrd->clkout[j]); + dev_err(&pdev->dev, + "unable to register divider clock\n"); + ret = PTR_ERR(clk_wzrd->clkout[i]); + goto err_rm_int_clks; + } + } + + kfree(clk_name); + + clk_wzrd->clk_data.clks = clk_wzrd->clkout; + clk_wzrd->clk_data.clk_num = ARRAY_SIZE(clk_wzrd->clkout); + of_clk_add_provider(np, of_clk_src_onecell_get, &clk_wzrd->clk_data); + + if (clk_wzrd->speed_grade) { + clk_wzrd->nb.notifier_call = clk_wzrd_clk_notifier; + + ret = clk_notifier_register(clk_wzrd->clk_in1, + &clk_wzrd->nb); + if (ret) + dev_warn(&pdev->dev, + "unable to register clock notifier\n"); + + ret = clk_notifier_register(clk_wzrd->axi_clk, &clk_wzrd->nb); + if (ret) + dev_warn(&pdev->dev, + "unable to register clock notifier\n"); + } + + return 0; + +err_rm_int_clks: + clk_unregister(clk_wzrd->clks_internal[1]); +err_rm_int_clk: + kfree(clk_name); + clk_unregister(clk_wzrd->clks_internal[0]); +err_disable_clk: + clk_disable_unprepare(clk_wzrd->axi_clk); + + return ret; +} + +static int clk_wzrd_remove(struct platform_device *pdev) +{ + int i; + struct clk_wzrd *clk_wzrd = platform_get_drvdata(pdev); + + of_clk_del_provider(pdev->dev.of_node); + + for (i = 0; i < WZRD_NUM_OUTPUTS; i++) + clk_unregister(clk_wzrd->clkout[i]); + for (i = 0; i < wzrd_clk_int_max; i++) + clk_unregister(clk_wzrd->clks_internal[i]); + + if (clk_wzrd->speed_grade) { + clk_notifier_unregister(clk_wzrd->axi_clk, &clk_wzrd->nb); + clk_notifier_unregister(clk_wzrd->clk_in1, &clk_wzrd->nb); + } + + clk_disable_unprepare(clk_wzrd->axi_clk); + + return 0; +} + +static const struct of_device_id clk_wzrd_ids[] = { + { .compatible = "xlnx,clocking-wizard" }, + { }, +}; +MODULE_DEVICE_TABLE(of, clk_wzrd_ids); + +static struct platform_driver clk_wzrd_driver = { + .driver = { + .name = "clk-wizard", + .of_match_table = clk_wzrd_ids, + .pm = &clk_wzrd_dev_pm_ops, + }, + .probe = clk_wzrd_probe, + .remove = clk_wzrd_remove, +}; +module_platform_driver(clk_wzrd_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Soeren Brinkmann <soren.brinkm...@xilinx.com"); +MODULE_DESCRIPTION("Driver for the Xilinx Clocking Wizard IP core"); diff --git a/drivers/staging/clocking-wizard/dt-binding.txt b/drivers/staging/clocking-wizard/dt-binding.txt new file mode 100644 index 000000000000..723271e93316 --- /dev/null +++ b/drivers/staging/clocking-wizard/dt-binding.txt @@ -0,0 +1,30 @@ +Binding for Xilinx Clocking Wizard IP Core + +This binding uses the common clock binding[1]. Details about the devices can be +found in the product guide[2]. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt +[2] Clocking Wizard Product Guide +http://www.xilinx.com/support/documentation/ip_documentation/clk_wiz/v5_1/pg065-clk-wiz.pdf + +Required properties: + - compatible: Must be 'xlnx,clocking-wizard' + - reg: Base and size of the cores register space + - clocks: Handle to input clock + - clock-names: Tuple containing 'clk_in1' and 's_axi_aclk' + - clock-output-names: Names for the output clocks + +Optional properties: + - speed-grade: Speed grade of the device (valid values are 1..3) + +Example: + clock-generator@40040000 { + reg = <0x40040000 0x1000>; + compatible = "xlnx,clocking-wizard"; + speed-grade = <1>; + clock-names = "clk_in1", "s_axi_aclk"; + clocks = <&clkc 15>, <&clkc 15>; + clock-output-names = "clk_out0", "clk_out1", "clk_out2", + "clk_out3", "clk_out4", "clk_out5", + "clk_out6", "clk_out7"; + }; -- 2.1.2.1.g5e69ed6 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
