Re: [PATCH 2/2] clk: socfpga: agilex: add clock driver for the Agilex platform

Stephen Boyd
2019-09-18T05:00:13Z

Quoting Dinh Nguyen (2019-09-17 18:34:59)
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 0cad76021297..ef2c96c0f1e0 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -18,6 +18,7 @@ endif
>
> # hardware specific clock types
> # please keep this section sorted lexicographically by file path name
> +obj-$(CONFIG_ARCH_AGILEX) += socfpga/

Sort by filepath, so all files come before all directories, and
directories have a different section in this file.

> obj-$(CONFIG_MACH_ASM9260) += clk-asm9260.o
> obj-$(CONFIG_COMMON_CLK_AXI_CLKGEN) += clk-axi-clkgen.o
> obj-$(CONFIG_ARCH_AXXIA) += clk-axm5516.o
> diff --git a/drivers/clk/socfpga/Makefile b/drivers/clk/socfpga/Makefile
> index ce5aa7802eb8..bf736f8d201a 100644
> --- a/drivers/clk/socfpga/Makefile
> +++ b/drivers/clk/socfpga/Makefile
> @@ -3,3 +3,5 @@ obj-$(CONFIG_ARCH_SOCFPGA) += clk.o clk-gate.o clk-pll.o clk-periph.o
> obj-$(CONFIG_ARCH_SOCFPGA) += clk-pll-a10.o clk-periph-a10.o clk-gate-a10.o
> obj-$(CONFIG_ARCH_STRATIX10) += clk-s10.o
> obj-$(CONFIG_ARCH_STRATIX10) += clk-pll-s10.o clk-periph-s10.o clk-gate-s10.o
> +obj-$(CONFIG_ARCH_AGILEX) += clk-agilex.o
> +obj-$(CONFIG_ARCH_AGILEX) += clk-pll-s10.o clk-periph-s10.o clk-gate-s10.o

Preferably keep this sorted on Kconfig name.

> diff --git a/drivers/clk/socfpga/clk-agilex.c b/drivers/clk/socfpga/clk-agilex.c
> new file mode 100644
> index 000000000000..7d5093f0b2c9
> --- /dev/null
> +++ b/drivers/clk/socfpga/clk-agilex.c
> @@ -0,0 +1,332 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019, Intel Corporation
> + */
> +#include <linux/slab.h>
> +#include <linux/clk-provider.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +
> +#include <dt-bindings/clock/agilex-clock.h>
> +
> +#include "stratix10-clk.h"
> +
> +static const char * const pll_mux[] = { "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk",};
> +static const char * const cntr_mux[] = { "main_pll", "periph_pll",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const boot_mux[] = { "osc1", "cb-intosc-hs-div2-clk",};
> +
> +static const char * const mpu_free_mux[] = {"main_pll_c0", "peri_pll_c0",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +
> +static const char * const noc_free_mux[] = {"main_pll_c1", "peri_pll_c1",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +
> +static const char * const emaca_free_mux[] = {"main_pll_c2", "peri_pll_c2",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const emacb_free_mux[] = {"main_pll_c3", "peri_pll_c3",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const emac_ptp_free_mux[] = {"main_pll_c3", "peri_pll_c3",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const gpio_db_free_mux[] = {"main_pll_c3", "peri_pll_c3",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const psi_ref_free_mux[] = {"main_pll_c3", "peri_pll_c3",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const sdmmc_free_mux[] = {"main_pll_c3", "peri_pll_c3",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const s2f_usr0_free_mux[] = {"main_pll_c2", "peri_pll_c2",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const s2f_usr1_free_mux[] = {"main_pll_c2", "peri_pll_c2",
> + "osc1", "cb-intosc-hs-div2-clk",
> + "f2s-free-clk"};
> +static const char * const mpu_mux[] = { "mpu_free_clk", "boot_clk",};
> +
> +static const char * const s2f_usr0_mux[] = {"f2s-free-clk", "boot_clk"};
> +static const char * const emac_mux[] = {"emaca_free_clk", "emacb_free_clk"};
> +static const char * const noc_mux[] = {"noc_free_clk", "boot_clk"};
> +
> +/* clocks in AO (always on) controller */
> +static const struct stratix10_pll_clock agilex_pll_clks[] = {
> + { AGILEX_BOOT_CLK, "boot_clk", boot_mux, ARRAY_SIZE(boot_mux), 0,
> + 0x0},
> + { AGILEX_MAIN_PLL_CLK, "main_pll", pll_mux, ARRAY_SIZE(pll_mux),
> + 0, 0x48},
> + { AGILEX_PERIPH_PLL_CLK, "periph_pll", pll_mux, ARRAY_SIZE(pll_mux),
> + 0, 0x9c},
> +};
> +
> +static const struct stratix10_perip_c_clock agilex_main_perip_c_clks[] = {
> + { AGILEX_MAIN_PLL_C0_CLK, "main_pll_c0", "main_pll", NULL, 1, 0, 0x58},
> + { AGILEX_MAIN_PLL_C1_CLK, "main_pll_c1", "main_pll", NULL, 1, 0, 0x5C},
> + { AGILEX_MAIN_PLL_C2_CLK, "main_pll_c2", "main_pll", NULL, 1, 0, 0x64},
> + { AGILEX_MAIN_PLL_C3_CLK, "main_pll_c3", "main_pll", NULL, 1, 0, 0x68},
> + { AGILEX_PERIPH_PLL_C0_CLK, "peri_pll_c0", "periph_pll", NULL, 1, 0, 0xAC},
> + { AGILEX_PERIPH_PLL_C1_CLK, "peri_pll_c1", "periph_pll", NULL, 1, 0, 0xB0},
> + { AGILEX_PERIPH_PLL_C2_CLK, "peri_pll_c2", "periph_pll", NULL, 1, 0, 0xB8},
> + { AGILEX_PERIPH_PLL_C3_CLK, "peri_pll_c3", "periph_pll", NULL, 1, 0, 0xBC},
> +};
> +
> +static const struct stratix10_perip_cnt_clock agilex_main_perip_cnt_clks[] = {
> + { AGILEX_MPU_FREE_CLK, "mpu_free_clk", NULL, mpu_free_mux, ARRAY_SIZE(mpu_free_mux),
> + 0, 0x3C, 0, 0, 0},
> + { AGILEX_NOC_FREE_CLK, "noc_free_clk", NULL, noc_free_mux, ARRAY_SIZE(noc_free_mux),
> + 0, 0x40, 0, 0, 1},
> + { AGILEX_L4_SYS_FREE_CLK, "l4_sys_free_clk", "noc_free_clk", NULL, 1, 0,
> + 0, 4, 0, 0},
> + { AGILEX_NOC_CLK, "noc_clk", NULL, noc_mux, ARRAY_SIZE(noc_mux),
> + 0, 0, 0, 0x30, 1},
> + { AGILEX_EMAC_A_FREE_CLK, "emaca_free_clk", NULL, emaca_free_mux, ARRAY_SIZE(emaca_free_mux),
> + 0, 0xD4, 0, 0x88, 0},
> + { AGILEX_EMAC_B_FREE_CLK, "emacb_free_clk", NULL, emacb_free_mux, ARRAY_SIZE(emacb_free_mux),
> + 0, 0xD8, 0, 0x88, 1},
> + { AGILEX_EMAC_PTP_FREE_CLK, "emac_ptp_free_clk", NULL, emac_ptp_free_mux,
> + ARRAY_SIZE(emac_ptp_free_mux), 0, 0xDC, 0, 0x88, 2},
> + { AGILEX_GPIO_DB_FREE_CLK, "gpio_db_free_clk", NULL, gpio_db_free_mux,
> + ARRAY_SIZE(gpio_db_free_mux), 0, 0xE0, 0, 0x88, 3},
> + { AGILEX_SDMMC_FREE_CLK, "sdmmc_free_clk", NULL, sdmmc_free_mux,
> + ARRAY_SIZE(sdmmc_free_mux), 0, 0xE4, 0, 0x88, 4},
> + { AGILEX_S2F_USER0_FREE_CLK, "s2f_user0_free_clk", NULL, s2f_usr0_free_mux,
> + ARRAY_SIZE(s2f_usr0_free_mux), 0, 0xE8, 0, 0, 0},
> + { AGILEX_S2F_USER1_FREE_CLK, "s2f_user1_free_clk", NULL, s2f_usr1_free_mux,
> + ARRAY_SIZE(s2f_usr1_free_mux), 0, 0xEC, 0, 0x88, 5},
> + { AGILEX_PSI_REF_FREE_CLK, "psi_ref_free_clk", NULL, psi_ref_free_mux,
> + ARRAY_SIZE(psi_ref_free_mux), 0, 0xF0, 0, 0x88, 6},
> +};
> +
> +static const struct stratix10_gate_clock agilex_gate_clks[] = {
> + { AGILEX_MPU_CLK, "mpu_clk", NULL, mpu_mux, ARRAY_SIZE(mpu_mux), 0, 0x24,
> + 0, 0, 0, 0, 0x30, 0, 0},
> + { AGILEX_MPU_PERIPH_CLK, "mpu_periph_clk", "mpu_clk", NULL, 1, 0, 0x24,
> + 0, 0, 0, 0, 0, 0, 4},
> + { AGILEX_MPU_L2RAM_CLK, "mpu_l2ram_clk", "mpu_clk", NULL, 1, 0, 0x24,
> + 0, 0, 0, 0, 0, 0, 2},
> + { AGILEX_L4_MAIN_CLK, "l4_main_clk", "noc_clk", NULL, 1, 0, 0x24,
> + 1, 0x44, 0, 2, 0, 0, 0},
> + { AGILEX_L4_MP_CLK, "l4_mp_clk", "noc_clk", NULL, 1, 0, 0x24,
> + 2, 0x44, 8, 2, 0, 0, 0},
> + { AGILEX_L4_SP_CLK, "l4_sp_clk", "noc_clk", NULL, 1, CLK_IS_CRITICAL, 0x24,

Please document why a clk is critical in the code.

> + 3, 0x44, 16, 2, 0, 0, 0},
> + { AGILEX_CS_AT_CLK, "cs_at_clk", "noc_clk", NULL, 1, 0, 0x24,
> + 4, 0x44, 24, 2, 0, 0, 0},
> + { AGILEX_CS_TRACE_CLK, "cs_trace_clk", "noc_clk", NULL, 1, 0, 0x24,
> + 4, 0x44, 26, 2, 0, 0, 0},
> + { AGILEX_CS_PDBG_CLK, "cs_pdbg_clk", "cs_at_clk", NULL, 1, 0, 0x24,
> + 4, 0x44, 28, 1, 0, 0, 0},
> + { AGILEX_CS_TIMER_CLK, "cs_timer_clk", "noc_clk", NULL, 1, 0, 0x24,
> + 5, 0, 0, 0, 0, 0, 0},
> + { AGILEX_S2F_USER0_CLK, "s2f_user0_clk", NULL, s2f_usr0_mux, ARRAY_SIZE(s2f_usr0_mux), 0, 0x24,
> + 6, 0, 0, 0, 0, 0, 0},
> + { AGILEX_EMAC0_CLK, "emac0_clk", NULL, emac_mux, ARRAY_SIZE(emac_mux), 0, 0x7C,
> + 0, 0, 0, 0, 0x94, 26, 0},
> + { AGILEX_EMAC1_CLK, "emac1_clk", NULL, emac_mux, ARRAY_SIZE(emac_mux), 0, 0x7C,
> + 1, 0, 0, 0, 0x94, 27, 0},
> + { AGILEX_EMAC2_CLK, "emac2_clk", NULL, emac_mux, ARRAY_SIZE(emac_mux), 0, 0x7C,
> + 2, 0, 0, 0, 0x94, 28, 0},
> + { AGILEX_EMAC_PTP_CLK, "emac_ptp_clk", "emac_ptp_free_clk", NULL, 1, 0, 0x7C,
> + 3, 0, 0, 0, 0, 0, 0},
> + { AGILEX_GPIO_DB_CLK, "gpio_db_clk", "gpio_db_free_clk", NULL, 1, 0, 0x7C,
> + 4, 0x98, 0, 16, 0, 0, 0},
> + { AGILEX_SDMMC_CLK, "sdmmc_clk", "sdmmc_free_clk", NULL, 1, 0, 0x7C,
> + 5, 0, 0, 0, 0, 0, 4},
> + { AGILEX_S2F_USER1_CLK, "s2f_user1_clk", "s2f_user1_free_clk", NULL, 1, 0, 0x7C,
> + 6, 0, 0, 0, 0, 0, 0},
> + { AGILEX_PSI_REF_CLK, "psi_ref_clk", "psi_ref_free_clk", NULL, 1, 0, 0x7C,
> + 7, 0, 0, 0, 0, 0, 0},
> + { AGILEX_USB_CLK, "usb_clk", "l4_mp_clk", NULL, 1, 0, 0x7C,
> + 8, 0, 0, 0, 0, 0, 0},
> + { AGILEX_SPI_M_CLK, "spi_m_clk", "l4_mp_clk", NULL, 1, 0, 0x7C,
> + 9, 0, 0, 0, 0, 0, 0},
> + { AGILEX_NAND_CLK, "nand_clk", "l4_main_clk", NULL, 1, 0, 0x7C,
> + 10, 0, 0, 0, 0, 0, 0},
> +};
> +
> +static int agilex_clk_register_c_perip(const struct stratix10_perip_c_clock *clks,
> + int nums, struct stratix10_clock_data *data)
> +{
> + struct clk *clk;
> + void __iomem *base = data->base;
> + int i;
> +
> + for (i = 0; i < nums; i++) {
> + clk = s10_register_periph(clks[i].name, clks[i].parent_name,
> + clks[i].parent_names, clks[i].num_parents,
> + clks[i].flags, base, clks[i].offset);
> + if (IS_ERR(clk)) {
> + pr_err("%s: failed to register clock %s\n",
> + __func__, clks[i].name);
> + continue;
> + }
> + data->clk_data.clks[clks[i].id] = clk;
> + }
> + return 0;
> +}
> +
> +static int agilex_clk_register_cnt_perip(const struct stratix10_perip_cnt_clock *clks,
> + int nums, struct stratix10_clock_data *data)
> +{
> + struct clk *clk;
> + void __iomem *base = data->base;
> + int i;
> +
> + for (i = 0; i < nums; i++) {
> + clk = s10_register_cnt_periph(clks[i].name, clks[i].parent_name,
> + clks[i].parent_names,
> + clks[i].num_parents,
> + clks[i].flags, base,
> + clks[i].offset,
> + clks[i].fixed_divider,
> + clks[i].bypass_reg,
> + clks[i].bypass_shift);
> + if (IS_ERR(clk)) {
> + pr_err("%s: failed to register clock %s\n",
> + __func__, clks[i].name);
> + continue;
> + }
> + data->clk_data.clks[clks[i].id] = clk;
> + }
> +
> + return 0;
> +}
> +
> +static int agilex_clk_register_gate(const struct stratix10_gate_clock *clks, int nums, struct stratix10_clock_data *data)
> +{

Something weird happened here.

> + struct clk *clk;
> + void __iomem *base = data->base;
> + int i;
> +
> + for (i = 0; i < nums; i++) {
> + clk = s10_register_gate(clks[i].name, clks[i].parent_name,
> + clks[i].parent_names,
> + clks[i].num_parents,
> + clks[i].flags, base,
> + clks[i].gate_reg,
> + clks[i].gate_idx, clks[i].div_reg,
> + clks[i].div_offset, clks[i].div_width,
> + clks[i].bypass_reg,
> + clks[i].bypass_shift,
> + clks[i].fixed_div);

Maybe s10_regsiter_gate should take a struct stratix10_gate_clock
instead?

> + if (IS_ERR(clk)) {
> + pr_err("%s: failed to register clock %s\n",
> + __func__, clks[i].name);
> + continue;
> + }
> + data->clk_data.clks[clks[i].id] = clk;
> + }
> +
> + return 0;
> +}
> +
> +static int agilex_clk_register_pll(const struct stratix10_pll_clock *clks,
> + int nums, struct stratix10_clock_data *data)
> +{
> + struct clk *clk;
> + void __iomem *base = data->base;
> + int i;
> +
> + for (i = 0; i < nums; i++) {
> + clk = agilex_register_pll(clks[i].name, clks[i].parent_names,
> + clks[i].num_parents,
> + clks[i].flags, base,
> + clks[i].offset);
> + if (IS_ERR(clk)) {
> + pr_err("%s: failed to register clock %s\n",
> + __func__, clks[i].name);
> + continue;
> + }
> + data->clk_data.clks[clks[i].id] = clk;

Hmm I just reviewed something that looked so similar. Please use some
local variables to simplify this line.

> + }
> +
> + return 0;
> +}
> +
> +static struct stratix10_clock_data *__socfpga_agilex_clk_init(struct platform_device *pdev,
> + int nr_clks)
> +{
> + struct device_node *np = pdev->dev.of_node;
> + struct device *dev = &pdev->dev;
> + struct stratix10_clock_data *clk_data;
> + struct clk **clk_table;
> + struct resource *res;
> + void __iomem *base;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + base = devm_ioremap_resource(dev, res);
> + if (IS_ERR(base)) {
> + pr_err("%s: failed to map clock registers\n", __func__);

devm_ioremap_resource() already prints this error. Also, there's a
helper now that gets the resource and maps it in one call instead of
two, please use it.

> + return ERR_CAST(base);
> + }
> +
> + clk_data = devm_kzalloc(dev, sizeof(*clk_data), GFP_KERNEL);
> + if (!clk_data)
> + return ERR_PTR(-ENOMEM);
> +
> + clk_data->base = base;
> + clk_table = devm_kcalloc(dev, nr_clks, sizeof(*clk_table), GFP_KERNEL);
> + if (!clk_table)
> + return ERR_PTR(-ENOMEM);
> +
> + clk_data->clk_data.clks = clk_table;
> + clk_data->clk_data.clk_num = nr_clks;
> + of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data->clk_data);

Please add the clk provider after registering all clks, not before.

> + return clk_data;
> +}
> +
> +static int agilex_clkmgr_init(struct platform_device *pdev)
> +{
> + struct stratix10_clock_data *clk_data;
> +
> + clk_data = __socfpga_agilex_clk_init(pdev, AGILEX_NUM_CLKS);
> + if (IS_ERR(clk_data))
> + return PTR_ERR(clk_data);

Please inline this init function here.

> +
> + agilex_clk_register_pll(agilex_pll_clks, ARRAY_SIZE(agilex_pll_clks), clk_data);
> +
> + agilex_clk_register_c_perip(agilex_main_perip_c_clks,
> + ARRAY_SIZE(agilex_main_perip_c_clks), clk_data);
> +
> + agilex_clk_register_cnt_perip(agilex_main_perip_cnt_clks,
> + ARRAY_SIZE(agilex_main_perip_cnt_clks),
> + clk_data);
> +
> + agilex_clk_register_gate(agilex_gate_clks, ARRAY_SIZE(agilex_gate_clks),
> + clk_data);
> + return 0;
> +}
> +
> +static int agilex_clkmgr_probe(struct platform_device *pdev)
> +{
> + return agilex_clkmgr_init(pdev);

Just inline the function into probe.

> +}
> diff --git a/drivers/clk/socfpga/clk-pll-s10.c b/drivers/clk/socfpga/clk-pll-s10.c
> index 4705eb544f01..e6ce0ec39494 100644
> --- a/drivers/clk/socfpga/clk-pll-s10.c
> +++ b/drivers/clk/socfpga/clk-pll-s10.c
> @@ -18,8 +18,12 @@
> #define SOCFPGA_PLL_RESET_MASK 0x2
> #define SOCFPGA_PLL_REFDIV_MASK 0x00003F00
> #define SOCFPGA_PLL_REFDIV_SHIFT 8
> +#define SOCFPGA_PLL_AREFDIV_MASK 0x00000F00
> +#define SOCFPGA_PLL_DREFDIV_MASK 0x00003000
> +#define SOCFPGA_PLL_DREFDIV_SHIFT 12
> #define SOCFPGA_PLL_MDIV_MASK 0xFF000000
> #define SOCFPGA_PLL_MDIV_SHIFT 24
> +#define SOCFPGA_AGILEX_PLL_MDIV_MASK 0x000003FF
> #define SWCTRLBTCLKSEL_MASK 0x200
> #define SWCTRLBTCLKSEL_SHIFT 9
>
> @@ -27,6 +31,27 @@
>
> #define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
>
> +static unsigned long agilex_clk_pll_recalc_rate(struct clk_hw *hwclk,
> + unsigned long parent_rate)
> +{
> + struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
> + unsigned long arefdiv, reg, mdiv;
> + unsigned long long vco_freq;
> +
> + /* read VCO1 reg for numerator and denominator */
> + reg = readl(socfpgaclk->hw.reg);
> + arefdiv = (reg & SOCFPGA_PLL_AREFDIV_MASK) >> SOCFPGA_PLL_REFDIV_SHIFT;
> +
> + vco_freq = (unsigned long long)parent_rate / arefdiv;

Is this a 64-bit div? Probably needs a do_div() call instead.

> +
> + /* Read mdiv and fdiv from the fdbck register */
> + reg = readl(socfpgaclk->hw.reg + 0x24);
> + mdiv = (reg & SOCFPGA_AGILEX_PLL_MDIV_MASK);
> +
> + vco_freq = (unsigned long long)vco_freq * mdiv;
> + return (unsigned long)vco_freq;

Drop the cast, it's implicit.

> +}
> +
> static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
> unsigned long parent_rate)
> {
> @@ -145,3 +176,42 @@ struct clk *s10_register_pll(const char *name, const char * const *parent_names,
> }
> return clk;
> }
> +
> +struct clk *agilex_register_pll(const char *name,
> + const char * const *parent_names,
> + u8 num_parents, unsigned long flags,
> + void __iomem *reg, unsigned long offset)
> +{
> + struct clk *clk;
> + struct socfpga_pll *pll_clk;
> + struct clk_init_data init;
> +
> + pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
> + if (WARN_ON(!pll_clk))
> + return NULL;
> +
> + pll_clk->hw.reg = reg + offset;
> +
> + if (streq(name, SOCFPGA_BOOT_CLK))
> + init.ops = &clk_boot_ops;
> + else
> + init.ops = &agilex_clk_pll_ops;
> +
> + init.name = name;
> + init.flags = flags;
> +
> + init.num_parents = num_parents;
> + init.parent_names = parent_names;

Is it possible to use the new way of specifying clk parents here so that
we don't have to keep using strings to describe the clk topology?

> + pll_clk->hw.hw.init = &init;
> +
> + pll_clk->hw.bit_idx = SOCFPGA_PLL_POWER;
> + clk_pll_ops.enable = clk_gate_ops.enable;
> + clk_pll_ops.disable = clk_gate_ops.disable;
> +
> + clk = clk_register(NULL, &pll_clk->hw.hw);

Any reason clk_hw_register() can't be used?

> + if (WARN_ON(IS_ERR(clk))) {
> + kfree(pll_clk);
> + return NULL;
> + }
> + return clk;
> +}