Re: [PATCH V3 XRT Alveo 14/18] fpga: xrt: clock platform driver

Tom Rix
2021-03-05T15:24:19Z

why are clock and clkfeq separated ?

On 2/17/21 10:40 PM, Lizhi Hou wrote:
> Add clock driver. Clock is a hardware function discovered by walking
> xclbin metadata. A platform device node will be created for it. Other
> part of driver configures clock through clock driver.
>
> Signed-off-by: Sonal Santan <sonal.santan@xilinx.com>
> Signed-off-by: Max Zhen <max.zhen@xilinx.com>
> Signed-off-by: Lizhi Hou <lizhih@xilinx.com>
> ---
> drivers/fpga/xrt/include/xleaf/clock.h | 31 ++
> drivers/fpga/xrt/lib/xleaf/clock.c | 648 +++++++++++++++++++++++++
> 2 files changed, 679 insertions(+)
> create mode 100644 drivers/fpga/xrt/include/xleaf/clock.h
> create mode 100644 drivers/fpga/xrt/lib/xleaf/clock.c
>
> diff --git a/drivers/fpga/xrt/include/xleaf/clock.h b/drivers/fpga/xrt/include/xleaf/clock.h
> new file mode 100644
> index 000000000000..a2da59b32551
> --- /dev/null
> +++ b/drivers/fpga/xrt/include/xleaf/clock.h
> @@ -0,0 +1,31 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Header file for XRT Clock Leaf Driver
> + *
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + * Lizhi Hou <Lizhi.Hou@xilinx.com>
> + */
> +
> +#ifndef _XRT_CLOCK_H_
> +#define _XRT_CLOCK_H_
> +
> +#include "xleaf.h"
> +#include <linux/xrt/xclbin.h>
> +
> +/*
> + * CLOCK driver IOCTL calls.
> + */
> +enum xrt_clock_ioctl_cmd {
> + XRT_CLOCK_SET = XRT_XLEAF_CUSTOM_BASE, /* See comments in xleaf.h */
> + XRT_CLOCK_GET,
> + XRT_CLOCK_VERIFY,
> +};
> +
> +struct xrt_clock_ioctl_get {
> + u16 freq;
> + u32 freq_cnter;
> +};
> +
> +#endif /* _XRT_CLOCK_H_ */
> diff --git a/drivers/fpga/xrt/lib/xleaf/clock.c b/drivers/fpga/xrt/lib/xleaf/clock.c
> new file mode 100644
> index 000000000000..a067b501a607
> --- /dev/null
> +++ b/drivers/fpga/xrt/lib/xleaf/clock.c
> @@ -0,0 +1,648 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Xilinx Alveo FPGA Clock Wizard Driver
> + *
> + * Copyright (C) 2020-2021 Xilinx, Inc.
> + *
> + * Authors:
> + * Lizhi Hou<Lizhi.Hou@xilinx.com>
> + * Sonal Santan <sonals@xilinx.com>
> + * David Zhang <davidzha@xilinx.com>
> + */
> +
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include "metadata.h"
> +#include "xleaf.h"
> +#include "xleaf/clock.h"
> +#include "xleaf/clkfreq.h"
> +
> +/* CLOCK_MAX_NUM_CLOCKS should be a concept from XCLBIN_ in the future */
> +#define CLOCK_MAX_NUM_CLOCKS 4
> +#define OCL_CLKWIZ_STATUS_OFFSET 0x4
OCL_CLKWIZ does not match the name of this file, change to something like XRT_CLOCK
> +#define OCL_CLKWIZ_STATUS_MASK 0xffff
> +#define OCL_CLKWIZ_STATUS_MEASURE_START 0x1
> +#define OCL_CLKWIZ_STATUS_MEASURE_DONE 0x2
> +#define OCL_CLKWIZ_CONFIG_OFFSET(n) (0x200 + 4 * (n))

This should be expanded to logical names of the registers.

It's use below has a magic indexes.

> +#define CLOCK_DEFAULT_EXPIRE_SECS 1
> +
> +#define CLOCK_ERR(clock, fmt, arg...) \
> + xrt_err((clock)->pdev, fmt "\n", ##arg)
> +#define CLOCK_WARN(clock, fmt, arg...) \
> + xrt_warn((clock)->pdev, fmt "\n", ##arg)
> +#define CLOCK_INFO(clock, fmt, arg...) \
> + xrt_info((clock)->pdev, fmt "\n", ##arg)
> +#define CLOCK_DBG(clock, fmt, arg...) \
> + xrt_dbg((clock)->pdev, fmt "\n", ##arg)
> +
> +#define XRT_CLOCK "xrt_clock"
> +
> +struct clock {
> + struct platform_device *pdev;
> + void __iomem *clock_base;
> + struct mutex clock_lock; /* clock dev lock */
> +
> + const char *clock_ep_name;
> +};
> +
> +/*
> + * Precomputed table with config0 and config2 register values together with
> + * target frequency. The steps are approximately 5 MHz apart. Table is
> + * generated by wiz.pl.
where is wiz.pl ? include the script
> + */
> +static const struct xmgmt_ocl_clockwiz {
> + /* target frequency */
> + unsigned short ocl;
> + /* config0 register */
> + unsigned long config0;
Should be u32
> + /* config2 register */
> + unsigned int config2;
> +} frequency_table[] = {
> + {/*1275.000*/ 10.000, 0x02EE0C01, 0x0001F47F},

Could clean up this table, to use spaces instead of tabs, move the comment out of branches

/* freq */ { ocl, config0, config2 },

> + {/*1575.000*/ 15.000, 0x02EE0F01, 0x00000069},
ocl is short, the data if float, change the generator output an integer
> + {/*1600.000*/ 20.000, 0x00001001, 0x00000050},
> + {/*1600.000*/ 25.000, 0x00001001, 0x00000040},
> + {/*1575.000*/ 30.000, 0x02EE0F01, 0x0001F434},
> + {/*1575.000*/ 35.000, 0x02EE0F01, 0x0000002D},
> + {/*1600.000*/ 40.000, 0x00001001, 0x00000028},
> + {/*1575.000*/ 45.000, 0x02EE0F01, 0x00000023},
> + {/*1600.000*/ 50.000, 0x00001001, 0x00000020},
> + {/*1512.500*/ 55.000, 0x007D0F01, 0x0001F41B},
> + {/*1575.000*/ 60.000, 0x02EE0F01, 0x0000FA1A},
> + {/*1462.500*/ 65.000, 0x02710E01, 0x0001F416},
> + {/*1575.000*/ 70.000, 0x02EE0F01, 0x0001F416},
> + {/*1575.000*/ 75.000, 0x02EE0F01, 0x00000015},
> + {/*1600.000*/ 80.000, 0x00001001, 0x00000014},
> + {/*1487.500*/ 85.000, 0x036B0E01, 0x0001F411},
> + {/*1575.000*/ 90.000, 0x02EE0F01, 0x0001F411},
> + {/*1425.000*/ 95.000, 0x00FA0E01, 0x0000000F},
> + {/*1600.000*/ 100.000, 0x00001001, 0x00000010},
> + {/*1575.000*/ 105.000, 0x02EE0F01, 0x0000000F},
> + {/*1512.500*/ 110.000, 0x007D0F01, 0x0002EE0D},
> + {/*1437.500*/ 115.000, 0x01770E01, 0x0001F40C},
> + {/*1575.000*/ 120.000, 0x02EE0F01, 0x00007D0D},
> + {/*1562.500*/ 125.000, 0x02710F01, 0x0001F40C},
> + {/*1462.500*/ 130.000, 0x02710E01, 0x0000FA0B},
> + {/*1350.000*/ 135.000, 0x01F40D01, 0x0000000A},
> + {/*1575.000*/ 140.000, 0x02EE0F01, 0x0000FA0B},
> + {/*1450.000*/ 145.000, 0x01F40E01, 0x0000000A},
> + {/*1575.000*/ 150.000, 0x02EE0F01, 0x0001F40A},
> + {/*1550.000*/ 155.000, 0x01F40F01, 0x0000000A},
> + {/*1600.000*/ 160.000, 0x00001001, 0x0000000A},
> + {/*1237.500*/ 165.000, 0x01770C01, 0x0001F407},
> + {/*1487.500*/ 170.000, 0x036B0E01, 0x0002EE08},
> + {/*1575.000*/ 175.000, 0x02EE0F01, 0x00000009},
> + {/*1575.000*/ 180.000, 0x02EE0F01, 0x0002EE08},
> + {/*1387.500*/ 185.000, 0x036B0D01, 0x0001F407},
> + {/*1425.000*/ 190.000, 0x00FA0E01, 0x0001F407},
> + {/*1462.500*/ 195.000, 0x02710E01, 0x0001F407},
> + {/*1600.000*/ 200.000, 0x00001001, 0x00000008},
> + {/*1537.500*/ 205.000, 0x01770F01, 0x0001F407},
> + {/*1575.000*/ 210.000, 0x02EE0F01, 0x0001F407},
> + {/*1075.000*/ 215.000, 0x02EE0A01, 0x00000005},
> + {/*1512.500*/ 220.000, 0x007D0F01, 0x00036B06},
> + {/*1575.000*/ 225.000, 0x02EE0F01, 0x00000007},
> + {/*1437.500*/ 230.000, 0x01770E01, 0x0000FA06},
> + {/*1175.000*/ 235.000, 0x02EE0B01, 0x00000005},
> + {/*1500.000*/ 240.000, 0x00000F01, 0x0000FA06},
> + {/*1225.000*/ 245.000, 0x00FA0C01, 0x00000005},
> + {/*1562.500*/ 250.000, 0x02710F01, 0x0000FA06},
> + {/*1275.000*/ 255.000, 0x02EE0C01, 0x00000005},
> + {/*1462.500*/ 260.000, 0x02710E01, 0x00027105},
> + {/*1325.000*/ 265.000, 0x00FA0D01, 0x00000005},
> + {/*1350.000*/ 270.000, 0x01F40D01, 0x00000005},
> + {/*1512.500*/ 275.000, 0x007D0F01, 0x0001F405},
> + {/*1575.000*/ 280.000, 0x02EE0F01, 0x00027105},
> + {/*1425.000*/ 285.000, 0x00FA0E01, 0x00000005},
> + {/*1450.000*/ 290.000, 0x01F40E01, 0x00000005},
> + {/*1475.000*/ 295.000, 0x02EE0E01, 0x00000005},
> + {/*1575.000*/ 300.000, 0x02EE0F01, 0x0000FA05},
> + {/*1525.000*/ 305.000, 0x00FA0F01, 0x00000005},
> + {/*1550.000*/ 310.000, 0x01F40F01, 0x00000005},
> + {/*1575.000*/ 315.000, 0x02EE0F01, 0x00000005},
> + {/*1600.000*/ 320.000, 0x00001001, 0x00000005},
> + {/*1462.500*/ 325.000, 0x02710E01, 0x0001F404},
> + {/*1237.500*/ 330.000, 0x01770C01, 0x0002EE03},
> + {/*837.500*/ 335.000, 0x01770801, 0x0001F402},
> + {/*1487.500*/ 340.000, 0x036B0E01, 0x00017704},
> + {/*862.500*/ 345.000, 0x02710801, 0x0001F402},
> + {/*1575.000*/ 350.000, 0x02EE0F01, 0x0001F404},
> + {/*887.500*/ 355.000, 0x036B0801, 0x0001F402},
> + {/*1575.000*/ 360.000, 0x02EE0F01, 0x00017704},
> + {/*912.500*/ 365.000, 0x007D0901, 0x0001F402},
> + {/*1387.500*/ 370.000, 0x036B0D01, 0x0002EE03},
> + {/*1500.000*/ 375.000, 0x00000F01, 0x00000004},
> + {/*1425.000*/ 380.000, 0x00FA0E01, 0x0002EE03},
> + {/*962.500*/ 385.000, 0x02710901, 0x0001F402},
> + {/*1462.500*/ 390.000, 0x02710E01, 0x0002EE03},
> + {/*987.500*/ 395.000, 0x036B0901, 0x0001F402},
> + {/*1600.000*/ 400.000, 0x00001001, 0x00000004},
> + {/*1012.500*/ 405.000, 0x007D0A01, 0x0001F402},
> + {/*1537.500*/ 410.000, 0x01770F01, 0x0002EE03},
> + {/*1037.500*/ 415.000, 0x01770A01, 0x0001F402},
> + {/*1575.000*/ 420.000, 0x02EE0F01, 0x0002EE03},
> + {/*1487.500*/ 425.000, 0x036B0E01, 0x0001F403},
> + {/*1075.000*/ 430.000, 0x02EE0A01, 0x0001F402},
> + {/*1087.500*/ 435.000, 0x036B0A01, 0x0001F402},
> + {/*1375.000*/ 440.000, 0x02EE0D01, 0x00007D03},
> + {/*1112.500*/ 445.000, 0x007D0B01, 0x0001F402},
> + {/*1575.000*/ 450.000, 0x02EE0F01, 0x0001F403},
> + {/*1137.500*/ 455.000, 0x01770B01, 0x0001F402},
> + {/*1437.500*/ 460.000, 0x01770E01, 0x00007D03},
> + {/*1162.500*/ 465.000, 0x02710B01, 0x0001F402},
> + {/*1175.000*/ 470.000, 0x02EE0B01, 0x0001F402},
> + {/*1425.000*/ 475.000, 0x00FA0E01, 0x00000003},
> + {/*1500.000*/ 480.000, 0x00000F01, 0x00007D03},
> + {/*1212.500*/ 485.000, 0x007D0C01, 0x0001F402},
> + {/*1225.000*/ 490.000, 0x00FA0C01, 0x0001F402},
> + {/*1237.500*/ 495.000, 0x01770C01, 0x0001F402},
> + {/*1562.500*/ 500.000, 0x02710F01, 0x00007D03},
> + {/*1262.500*/ 505.000, 0x02710C01, 0x0001F402},
> + {/*1275.000*/ 510.000, 0x02EE0C01, 0x0001F402},
> + {/*1287.500*/ 515.000, 0x036B0C01, 0x0001F402},
> + {/*1300.000*/ 520.000, 0x00000D01, 0x0001F402},
> + {/*1575.000*/ 525.000, 0x02EE0F01, 0x00000003},
> + {/*1325.000*/ 530.000, 0x00FA0D01, 0x0001F402},
> + {/*1337.500*/ 535.000, 0x01770D01, 0x0001F402},
> + {/*1350.000*/ 540.000, 0x01F40D01, 0x0001F402},
> + {/*1362.500*/ 545.000, 0x02710D01, 0x0001F402},
> + {/*1512.500*/ 550.000, 0x007D0F01, 0x0002EE02},
> + {/*1387.500*/ 555.000, 0x036B0D01, 0x0001F402},
> + {/*1400.000*/ 560.000, 0x00000E01, 0x0001F402},
> + {/*1412.500*/ 565.000, 0x007D0E01, 0x0001F402},
> + {/*1425.000*/ 570.000, 0x00FA0E01, 0x0001F402},
> + {/*1437.500*/ 575.000, 0x01770E01, 0x0001F402},
> + {/*1450.000*/ 580.000, 0x01F40E01, 0x0001F402},
> + {/*1462.500*/ 585.000, 0x02710E01, 0x0001F402},
> + {/*1475.000*/ 590.000, 0x02EE0E01, 0x0001F402},
> + {/*1487.500*/ 595.000, 0x036B0E01, 0x0001F402},
> + {/*1575.000*/ 600.000, 0x02EE0F01, 0x00027102},
> + {/*1512.500*/ 605.000, 0x007D0F01, 0x0001F402},
> + {/*1525.000*/ 610.000, 0x00FA0F01, 0x0001F402},
> + {/*1537.500*/ 615.000, 0x01770F01, 0x0001F402},
> + {/*1550.000*/ 620.000, 0x01F40F01, 0x0001F402},
> + {/*1562.500*/ 625.000, 0x02710F01, 0x0001F402},
> + {/*1575.000*/ 630.000, 0x02EE0F01, 0x0001F402},
> + {/*1587.500*/ 635.000, 0x036B0F01, 0x0001F402},
> + {/*1600.000*/ 640.000, 0x00001001, 0x0001F402},
> + {/*1290.000*/ 645.000, 0x01F44005, 0x00000002},
> + {/*1462.500*/ 650.000, 0x02710E01, 0x0000FA02}
> +};
> +
> +static inline u32 reg_rd(struct clock *clock, u32 offset)
> +{
> + return ioread32(clock->clock_base + offset);
> +}
> +
> +static inline void reg_wr(struct clock *clock, u32 val, u32 offset)
> +{
> + iowrite32(val, clock->clock_base + offset);
> +}
> +
> +static u32 find_matching_freq_config(unsigned short freq,
> + const struct xmgmt_ocl_clockwiz *table,
> + int size)
> +{
> + u32 start = 0;
> + u32 end = size - 1;
> + u32 idx = size - 1;
looks like you are doing a binary search, why not start idx at size / 2 ?
> +
> + if (freq < table[0].ocl)
> + return 0;
> +
> + if (freq > table[size - 1].ocl)
> + return size - 1;
> +
What aren't these two conditions errors ?
> + while (start < end) {
> + if (freq == table[idx].ocl)
> + break;
> + if (freq < table[idx].ocl)
> + end = idx;
> + else
> + start = idx + 1;
> + idx = start + (end - start) / 2;
> + }
> + if (freq < table[idx].ocl)
> + idx--;
> +
> + return idx;
> +}
> +
> +static u32 find_matching_freq(u32 freq,
> + const struct xmgmt_ocl_clockwiz *freq_table,
> + int freq_table_size)
> +{
> + int idx = find_matching_freq_config(freq, freq_table, freq_table_size);
> +
> + return freq_table[idx].ocl;
> +}
> +
> +static inline int clock_wiz_busy(struct clock *clock, int cycle, int interval)
> +{
> + u32 val = 0;
> + int count;
> +
> + val = reg_rd(clock, OCL_CLKWIZ_STATUS_OFFSET);
> + for (count = 0; val != 1 && count < cycle; count++) {
> + mdelay(interval);
> + val = reg_rd(clock, OCL_CLKWIZ_STATUS_OFFSET);

if (val == 1)

break;

Is a bit easier to  follow than putting another condition in the for()

> + }
> + if (val != 1) {
> + CLOCK_ERR(clock, "clockwiz is (%u) busy after %d ms",
> + val, cycle * interval);
> + return -ETIMEDOUT;
> + }
> +
> + return 0;
> +}
> +
> +static int get_freq(struct clock *clock, u16 *freq)
> +{
> +#define XCL_INPUT_FREQ 100

??

If this a real parameter, it needs to go in the clock.h

> + const u64 input = XCL_INPUT_FREQ;
> + u32 val;
> + u32 mul0, div0;
> + u32 mul_frac0 = 0;
> + u32 div1;
> + u32 div_frac1 = 0;
> +
> + WARN_ON(!mutex_is_locked(&clock->clock_lock));
> +
> + val = reg_rd(clock, OCL_CLKWIZ_STATUS_OFFSET);
> + if ((val & 0x1) == 0) {
> + CLOCK_ERR(clock, "clockwiz is busy %x", val);
> + *freq = 0;
> + return -EBUSY;
> + }
> +
> + val = reg_rd(clock, OCL_CLKWIZ_CONFIG_OFFSET(0));

A general problem.

The '0' is magic, convert this to a logically named #define or enum.

> +
> + div0 = val & 0xff;
> + mul0 = (val & 0xff00) >> 8;
> + if (val & BIT(26)) {
> + mul_frac0 = val >> 16;
> + mul_frac0 &= 0x3ff;
> + }
> +
> + /*
> + * Multiply both numerator (mul0) and the denominator (div0) with 1000
> + * to account for fractional portion of multiplier
> + */
> + mul0 *= 1000;
> + mul0 += mul_frac0;
> + div0 *= 1000;
> +
> + val = reg_rd(clock, OCL_CLKWIZ_CONFIG_OFFSET(2));
> +
> + div1 = val & 0xff;
> + if (val & BIT(18)) {
> + div_frac1 = val >> 8;
> + div_frac1 &= 0x3ff;
> + }
> +
> + /*
> + * Multiply both numerator (mul0) and the denominator (div1) with
> + * 1000 to account for fractional portion of divider
> + */
> +
> + div1 *= 1000;
> + div1 += div_frac1;
> + div0 *= div1;
> + mul0 *= 1000;
> + if (div0 == 0) {
> + CLOCK_ERR(clock, "clockwiz 0 divider");
> + return 0;
> + }
> +
> + *freq = (u16)((input * mul0) / div0);
> +
> + return 0;
> +}
> +
> +static int set_freq(struct clock *clock, u16 freq)
> +{
> + u32 config;
> + int err;
> + u32 idx = 0;
> + u32 val;
> +
> + WARN_ON(!mutex_is_locked(&clock->clock_lock));
> +
> + idx = find_matching_freq_config(freq, frequency_table,
> + ARRAY_SIZE(frequency_table));
> +
> + CLOCK_INFO(clock, "New: %d Mhz", freq);
> + err = clock_wiz_busy(clock, 20, 50);
> + if (err)
> + return -EBUSY;
> +
> + config = frequency_table[idx].config0;
> + reg_wr(clock, config, OCL_CLKWIZ_CONFIG_OFFSET(0));
> +
> + config = frequency_table[idx].config2;
> + reg_wr(clock, config, OCL_CLKWIZ_CONFIG_OFFSET(2));
> +
> + mdelay(10);
> + reg_wr(clock, 7, OCL_CLKWIZ_CONFIG_OFFSET(23));
> +
> + mdelay(1);
> + reg_wr(clock, 2, OCL_CLKWIZ_CONFIG_OFFSET(23));
> +
> + CLOCK_INFO(clock, "clockwiz waiting for locked signal");
> +
> + err = clock_wiz_busy(clock, 100, 100);
> + if (err) {
> + CLOCK_ERR(clock, "clockwiz MMCM/PLL did not lock");
> + /* restore */
> + reg_wr(clock, 4, OCL_CLKWIZ_CONFIG_OFFSET(23));
> + mdelay(10);
> + reg_wr(clock, 0, OCL_CLKWIZ_CONFIG_OFFSET(23));
> + return err;
> + }
> + val = reg_rd(clock, OCL_CLKWIZ_CONFIG_OFFSET(0));
> + CLOCK_INFO(clock, "clockwiz CONFIG(0) 0x%x", val);
> + val = reg_rd(clock, OCL_CLKWIZ_CONFIG_OFFSET(2));
> + CLOCK_INFO(clock, "clockwiz CONFIG(2) 0x%x", val);
> +
> + return 0;
> +}
> +
> +static int get_freq_counter(struct clock *clock, u32 *freq)
> +{
> + const void *cnter;
variable name should be easy to read, use 'counter'
> + struct platform_device *cnter_leaf;
> + struct platform_device *pdev = clock->pdev;
> + struct xrt_subdev_platdata *pdata = DEV_PDATA(clock->pdev);
> + int err = xrt_md_get_prop(DEV(pdev), pdata->xsp_dtb,
> + clock->clock_ep_name, NULL, XRT_MD_PROP_CLK_CNT, &cnter, NULL);
> +
> + WARN_ON(!mutex_is_locked(&clock->clock_lock));
> +
> + if (err) {
> + xrt_err(pdev, "no counter specified");
> + return err;
> + }
> +
> + cnter_leaf = xleaf_get_leaf_by_epname(pdev, cnter);
> + if (!cnter_leaf) {
> + xrt_err(pdev, "can't find counter");
> + return -ENOENT;
> + }
> +
> + err = xleaf_ioctl(cnter_leaf, XRT_CLKFREQ_READ, freq);
> + if (err)
> + xrt_err(pdev, "can't read counter");
> + xleaf_put_leaf(clock->pdev, cnter_leaf);
> +
> + return err;
> +}
> +
> +static int clock_get_freq(struct clock *clock, u16 *freq, u32 *freq_cnter)
> +{
> + int err = 0;
> +
> + mutex_lock(&clock->clock_lock);
> +
> + if (err == 0 && freq)
> + err = get_freq(clock, freq);
> +
> + if (err == 0 && freq_cnter)
> + err = get_freq_counter(clock, freq_cnter);
> +
> + mutex_unlock(&clock->clock_lock);
> + return err;
> +}
> +
> +static int clock_set_freq(struct clock *clock, u16 freq)
> +{
> + int err;

Why is this function needed ?

Move the locking into set_freq.

> +
> + mutex_lock(&clock->clock_lock);
> + err = set_freq(clock, freq);
> + mutex_unlock(&clock->clock_lock);
> +
> + return err;
> +}
> +
> +static int clock_verify_freq(struct clock *clock)
> +{
> + int err = 0;
> + u16 freq;
> + u32 lookup_freq, clock_freq_counter, request_in_khz, tolerance;
> +
> + mutex_lock(&clock->clock_lock);
> +
> + err = get_freq(clock, &freq);
> + if (err) {
> + xrt_err(clock->pdev, "get freq failed, %d", err);
> + goto end;
> + }
> +
> + err = get_freq_counter(clock, &clock_freq_counter);
> + if (err) {
> + xrt_err(clock->pdev, "get freq counter failed, %d", err);
> + goto end;
> + }
> +
> + lookup_freq = find_matching_freq(freq, frequency_table,
> + ARRAY_SIZE(frequency_table));
> + request_in_khz = lookup_freq * 1000;
> + tolerance = lookup_freq * 50;
> + if (tolerance < abs(clock_freq_counter - request_in_khz)) {
> + CLOCK_ERR(clock,
> + "set clock(%s) failed, request %ukhz, actual %dkhz",
> + clock->clock_ep_name, request_in_khz, clock_freq_counter);
> + err = -EDOM;
> + } else {
> + CLOCK_INFO(clock, "verified clock (%s)", clock->clock_ep_name);
> + }
> +
> +end:
> + mutex_unlock(&clock->clock_lock);
> + return err;
> +}
> +
> +static int clock_init(struct clock *clock)
> +{
> + struct xrt_subdev_platdata *pdata = DEV_PDATA(clock->pdev);
> + int err = 0;
> + const u16 *freq;
> +
> + err = xrt_md_get_prop(DEV(clock->pdev), pdata->xsp_dtb,
> + clock->clock_ep_name, NULL, XRT_MD_PROP_CLK_FREQ,
> + (const void **)&freq, NULL);
> + if (err) {
> + xrt_info(clock->pdev, "no default freq");
> + return 0;
> + }
> +
> + mutex_lock(&clock->clock_lock);
> + err = set_freq(clock, be16_to_cpu(*freq));
> + mutex_unlock(&clock->clock_lock);
> +
> + return err;
> +}
> +
> +static ssize_t freq_show(struct device *dev, struct device_attribute *attr, char *buf)
> +{
> + struct clock *clock = platform_get_drvdata(to_platform_device(dev));
> + u16 freq = 0;
> + ssize_t count;
> +
> + count = clock_get_freq(clock, &freq, NULL);
> + if (count < 0)
> + return count;
> +
> + count = snprintf(buf, 64, "%d\n", freq);

%u ?

Tom

> +
> + return count;
> +}
> +static DEVICE_ATTR_RO(freq);
> +
> +static struct attribute *clock_attrs[] = {
> + &dev_attr_freq.attr,
> + NULL,
> +};
> +
> +static struct attribute_group clock_attr_group = {
> + .attrs = clock_attrs,
> +};
> +
> +static int
> +xrt_clock_leaf_ioctl(struct platform_device *pdev, u32 cmd, void *arg)
> +{
> + struct clock *clock;
> + int ret = 0;
> +
> + clock = platform_get_drvdata(pdev);
> +
> + switch (cmd) {
> + case XRT_XLEAF_EVENT:
> + /* Does not handle any event. */
> + break;
> + case XRT_CLOCK_SET: {
> + u16 freq = (u16)(uintptr_t)arg;
> +
> + ret = clock_set_freq(clock, freq);
> + break;
> + }
> + case XRT_CLOCK_VERIFY: {
> + ret = clock_verify_freq(clock);
> + break;
> + }
> + case XRT_CLOCK_GET: {
> + struct xrt_clock_ioctl_get *get =
> + (struct xrt_clock_ioctl_get *)arg;
> +
> + ret = clock_get_freq(clock, &get->freq, &get->freq_cnter);
> + break;
> + }
> + default:
> + xrt_err(pdev, "unsupported cmd %d", cmd);
> + return -EINVAL;
> + }
> +
> + return ret;
> +}
> +
> +static int clock_remove(struct platform_device *pdev)
> +{
> + struct clock *clock;
> +
> + clock = platform_get_drvdata(pdev);
> + if (!clock) {
> + xrt_err(pdev, "driver data is NULL");
> + return -EINVAL;
> + }
> +
> + platform_set_drvdata(pdev, NULL);
> + devm_kfree(&pdev->dev, clock);
> +
> + CLOCK_INFO(clock, "successfully removed Clock subdev");
> + return 0;
> +}
> +
> +static int clock_probe(struct platform_device *pdev)
> +{
> + struct clock *clock = NULL;
> + struct resource *res;
> + int ret;
> +
> + clock = devm_kzalloc(&pdev->dev, sizeof(*clock), GFP_KERNEL);
> + if (!clock)
> + return -ENOMEM;
> +
> + platform_set_drvdata(pdev, clock);
> + clock->pdev = pdev;
> + mutex_init(&clock->clock_lock);
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + clock->clock_base = ioremap(res->start, res->end - res->start + 1);
> + if (!clock->clock_base) {
> + CLOCK_ERR(clock, "map base %pR failed", res);
> + ret = -EFAULT;
> + goto failed;
> + }
> +
> + clock->clock_ep_name = res->name;
> +
> + ret = clock_init(clock);
> + if (ret)
> + goto failed;
> +
> + ret = sysfs_create_group(&pdev->dev.kobj, &clock_attr_group);
> + if (ret) {
> + CLOCK_ERR(clock, "create clock attrs failed: %d", ret);
> + goto failed;
> + }
> +
> + CLOCK_INFO(clock, "successfully initialized Clock subdev");
> +
> + return 0;
> +
> +failed:
> + clock_remove(pdev);
> + return ret;
> +}
> +
> +static struct xrt_subdev_endpoints xrt_clock_endpoints[] = {
> + {
> + .xse_names = (struct xrt_subdev_ep_names[]) {
> + { .regmap_name = "clkwiz" },
> + { NULL },
> + },
> + .xse_min_ep = 1,
> + },
> + { 0 },
> +};
> +
> +static struct xrt_subdev_drvdata xrt_clock_data = {
> + .xsd_dev_ops = {
> + .xsd_ioctl = xrt_clock_leaf_ioctl,
> + },
> +};
> +
> +static const struct platform_device_id xrt_clock_table[] = {
> + { XRT_CLOCK, (kernel_ulong_t)&xrt_clock_data },
> + { },
> +};
> +
> +static struct platform_driver xrt_clock_driver = {
> + .driver = {
> + .name = XRT_CLOCK,
> + },
> + .probe = clock_probe,
> + .remove = clock_remove,
> + .id_table = xrt_clock_table,
> +};
> +
> +void clock_leaf_init_fini(bool init)
> +{
> + if (init)
> + xleaf_register_driver(XRT_SUBDEV_CLOCK, &xrt_clock_driver, xrt_clock_endpoints);
> + else
> + xleaf_unregister_driver(XRT_SUBDEV_CLOCK);
> +}