// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2016, The Linux Foundation. All rights reserved.
 * Copyright (C) 2013 Red Hat
 * Author: Rob Clark <robdclark@gmail.com>
 */

#include <linux/clk-provider.h>
#include <linux/delay.h>

#include "hdmi.h"

struct hdmi_pll_8960 {
        struct platform_device *pdev;
        struct clk_hw clk_hw;
        void __iomem *mmio;

        unsigned long pixclk;
};

#define hw_clk_to_pll(x) container_of(x, struct hdmi_pll_8960, clk_hw)

/*
 * HDMI PLL:
 *
 * To get the parent clock setup properly, we need to plug in hdmi pll
 * configuration into common-clock-framework.
 */

struct pll_rate {
        unsigned long rate;
        int num_reg;
        struct {
                u32 val;
                u32 reg;
        } conf[32];
};

/* NOTE: keep sorted highest freq to lowest: */
static const struct pll_rate freqtbl[] = {
        { 154000000, 14, {
                { 0x08, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x20, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0xf9, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x02, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x03, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG3   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x0d, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x4d, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0x5e, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0x42, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                        }
        },
        /* 1080p60/1080p50 case */
        { 148500000, 27, {
                { 0x02, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x02, REG_HDMI_8960_PHY_PLL_CHRG_PUMP_CFG },
                { 0x01, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0x33, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x2c, REG_HDMI_8960_PHY_PLL_IDAC_ADJ_CFG  },
                { 0x06, REG_HDMI_8960_PHY_PLL_I_VI_KVCO_CFG },
                { 0x0a, REG_HDMI_8960_PHY_PLL_PWRDN_B       },
                { 0x76, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x01, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0x4c, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0xc0, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                { 0x9a, REG_HDMI_8960_PHY_PLL_SSC_CFG0      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG1      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG2      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG3      },
                { 0x10, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG0  },
                { 0x1a, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG1  },
                { 0x0d, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG2  },
                { 0xe6, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x02, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG3   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x33, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG6   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG7   },
                        }
        },
        { 108000000, 13, {
                { 0x08, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x21, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0xf9, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x1c, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x02, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x49, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x49, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                        }
        },
        /* 720p60/720p50/1080i60/1080i50/1080p24/1080p30/1080p25 */
        { 74250000, 8, {
                { 0x0a, REG_HDMI_8960_PHY_PLL_PWRDN_B       },
                { 0x12, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x01, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0x33, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x76, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0xe6, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x02, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                        }
        },
        { 74176000, 14, {
                { 0x18, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x20, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0xf9, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0xe5, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x02, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG3   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x0c, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x4c, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0x7d, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0xbc, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                        }
        },
        { 65000000, 14, {
                { 0x18, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x20, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0xf9, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x8a, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x02, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG3   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x0b, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x4b, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0x7b, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0x09, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                        }
        },
        /* 480p60/480i60 */
        { 27030000, 18, {
                { 0x0a, REG_HDMI_8960_PHY_PLL_PWRDN_B       },
                { 0x38, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x02, REG_HDMI_8960_PHY_PLL_CHRG_PUMP_CFG },
                { 0x20, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0xff, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x4e, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0xd7, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0x03, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                { 0x2a, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x03, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG3   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x33, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG6   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG7   },
                        }
        },
        /* 576p50/576i50 */
        { 27000000, 27, {
                { 0x32, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x02, REG_HDMI_8960_PHY_PLL_CHRG_PUMP_CFG },
                { 0x01, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0x33, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x2c, REG_HDMI_8960_PHY_PLL_IDAC_ADJ_CFG  },
                { 0x06, REG_HDMI_8960_PHY_PLL_I_VI_KVCO_CFG },
                { 0x0a, REG_HDMI_8960_PHY_PLL_PWRDN_B       },
                { 0x7b, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x01, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0x4c, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0xc0, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                { 0x9a, REG_HDMI_8960_PHY_PLL_SSC_CFG0      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG1      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG2      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG3      },
                { 0x10, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG0  },
                { 0x1a, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG1  },
                { 0x0d, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG2  },
                { 0x2a, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x03, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG3   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x33, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG6   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG7   },
                        }
        },
        /* 640x480p60 */
        { 25200000, 27, {
                { 0x32, REG_HDMI_8960_PHY_PLL_REFCLK_CFG    },
                { 0x02, REG_HDMI_8960_PHY_PLL_CHRG_PUMP_CFG },
                { 0x01, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG0 },
                { 0x33, REG_HDMI_8960_PHY_PLL_LOOP_FLT_CFG1 },
                { 0x2c, REG_HDMI_8960_PHY_PLL_IDAC_ADJ_CFG  },
                { 0x06, REG_HDMI_8960_PHY_PLL_I_VI_KVCO_CFG },
                { 0x0a, REG_HDMI_8960_PHY_PLL_PWRDN_B       },
                { 0x77, REG_HDMI_8960_PHY_PLL_SDM_CFG0      },
                { 0x4c, REG_HDMI_8960_PHY_PLL_SDM_CFG1      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG2      },
                { 0xc0, REG_HDMI_8960_PHY_PLL_SDM_CFG3      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SDM_CFG4      },
                { 0x9a, REG_HDMI_8960_PHY_PLL_SSC_CFG0      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG1      },
                { 0x00, REG_HDMI_8960_PHY_PLL_SSC_CFG2      },
                { 0x20, REG_HDMI_8960_PHY_PLL_SSC_CFG3      },
                { 0x10, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG0  },
                { 0x1a, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG1  },
                { 0x0d, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG2  },
                { 0xf4, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG0   },
                { 0x02, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG1   },
                { 0x3b, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG2   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG3   },
                { 0x86, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG4   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG5   },
                { 0x33, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG6   },
                { 0x00, REG_HDMI_8960_PHY_PLL_VCOCAL_CFG7   },
                        }
        },
};

static inline void pll_write(struct hdmi_pll_8960 *pll, u32 reg, u32 data)
{
        msm_writel(data, pll->mmio + reg);
}

static inline u32 pll_read(struct hdmi_pll_8960 *pll, u32 reg)
{
        return msm_readl(pll->mmio + reg);
}

static inline struct hdmi_phy *pll_get_phy(struct hdmi_pll_8960 *pll)
{
        return platform_get_drvdata(pll->pdev);
}

static int hdmi_pll_enable(struct clk_hw *hw)
{
        struct hdmi_pll_8960 *pll = hw_clk_to_pll(hw);
        struct hdmi_phy *phy = pll_get_phy(pll);
        int timeout_count, pll_lock_retry = 10;
        unsigned int val;

        DBG("");

        /* Assert PLL S/W reset */
        pll_write(pll, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG2, 0x8d);
        pll_write(pll, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG0, 0x10);
        pll_write(pll, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG1, 0x1a);

        /* Wait for a short time before de-asserting
         * to allow the hardware to complete its job.
         * This much of delay should be fine for hardware
         * to assert and de-assert.
         */
        udelay(10);

        /* De-assert PLL S/W reset */
        pll_write(pll, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG2, 0x0d);

        val = hdmi_phy_read(phy, REG_HDMI_8960_PHY_REG12);
        val |= HDMI_8960_PHY_REG12_SW_RESET;
        /* Assert PHY S/W reset */
        hdmi_phy_write(phy, REG_HDMI_8960_PHY_REG12, val);
        val &= ~HDMI_8960_PHY_REG12_SW_RESET;
        /*
         * Wait for a short time before de-asserting to allow the hardware to
         * complete its job. This much of delay should be fine for hardware to
         * assert and de-assert.
         */
        udelay(10);
        /* De-assert PHY S/W reset */
        hdmi_phy_write(phy, REG_HDMI_8960_PHY_REG12, val);
        hdmi_phy_write(phy, REG_HDMI_8960_PHY_REG2,  0x3f);

        val = hdmi_phy_read(phy, REG_HDMI_8960_PHY_REG12);
        val |= HDMI_8960_PHY_REG12_PWRDN_B;
        hdmi_phy_write(phy, REG_HDMI_8960_PHY_REG12, val);
        /* Wait 10 us for enabling global power for PHY */
        mb();
        udelay(10);

        val = pll_read(pll, REG_HDMI_8960_PHY_PLL_PWRDN_B);
        val |= HDMI_8960_PHY_PLL_PWRDN_B_PLL_PWRDN_B;
        val &= ~HDMI_8960_PHY_PLL_PWRDN_B_PD_PLL;
        pll_write(pll, REG_HDMI_8960_PHY_PLL_PWRDN_B, val);
        hdmi_phy_write(phy, REG_HDMI_8960_PHY_REG2, 0x80);

        timeout_count = 1000;
        while (--pll_lock_retry > 0) {
                /* are we there yet? */
                val = pll_read(pll, REG_HDMI_8960_PHY_PLL_STATUS0);
                if (val & HDMI_8960_PHY_PLL_STATUS0_PLL_LOCK)
                        break;

                udelay(1);

                if (--timeout_count > 0)
                        continue;

                /*
                 * PLL has still not locked.
                 * Do a software reset and try again
                 * Assert PLL S/W reset first
                 */
                pll_write(pll, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG2, 0x8d);
                udelay(10);
                pll_write(pll, REG_HDMI_8960_PHY_PLL_LOCKDET_CFG2, 0x0d);

                /*
                 * Wait for a short duration for the PLL calibration
                 * before checking if the PLL gets locked
                 */
                udelay(350);

                timeout_count = 1000;
        }

        return 0;
}

static void hdmi_pll_disable(struct clk_hw *hw)
{
        struct hdmi_pll_8960 *pll = hw_clk_to_pll(hw);
        struct hdmi_phy *phy = pll_get_phy(pll);
        unsigned int val;

        DBG("");

        val = hdmi_phy_read(phy, REG_HDMI_8960_PHY_REG12);
        val &= ~HDMI_8960_PHY_REG12_PWRDN_B;
        hdmi_phy_write(phy, REG_HDMI_8960_PHY_REG12, val);

        val = pll_read(pll, REG_HDMI_8960_PHY_PLL_PWRDN_B);
        val |= HDMI_8960_PHY_REG12_SW_RESET;
        val &= ~HDMI_8960_PHY_REG12_PWRDN_B;
        pll_write(pll, REG_HDMI_8960_PHY_PLL_PWRDN_B, val);
        /* Make sure HDMI PHY/PLL are powered down */
        mb();
}

static const struct pll_rate *find_rate(unsigned long rate)
{
        int i;

        for (i = 1; i < ARRAY_SIZE(freqtbl); i++)
                if (rate > freqtbl[i].rate)
                        return &freqtbl[i - 1];

        return &freqtbl[i - 1];
}

static unsigned long hdmi_pll_recalc_rate(struct clk_hw *hw,
                                          unsigned long parent_rate)
{
        struct hdmi_pll_8960 *pll = hw_clk_to_pll(hw);

        return pll->pixclk;
}

static long hdmi_pll_round_rate(struct clk_hw *hw, unsigned long rate,
                                unsigned long *parent_rate)
{
        const struct pll_rate *pll_rate = find_rate(rate);

        return pll_rate->rate;
}

static int hdmi_pll_set_rate(struct clk_hw *hw, unsigned long rate,
                             unsigned long parent_rate)
{
        struct hdmi_pll_8960 *pll = hw_clk_to_pll(hw);
        const struct pll_rate *pll_rate = find_rate(rate);
        int i;

        DBG("rate=%lu", rate);

        for (i = 0; i < pll_rate->num_reg; i++)
                pll_write(pll, pll_rate->conf[i].reg, pll_rate->conf[i].val);

        pll->pixclk = rate;

        return 0;
}

static const struct clk_ops hdmi_pll_ops = {
        .enable = hdmi_pll_enable,
        .disable = hdmi_pll_disable,
        .recalc_rate = hdmi_pll_recalc_rate,
        .round_rate = hdmi_pll_round_rate,
        .set_rate = hdmi_pll_set_rate,
};

static const char * const hdmi_pll_parents[] = {
        "pxo",
};

static struct clk_init_data pll_init = {
        .name = "hdmi_pll",
        .ops = &hdmi_pll_ops,
        .parent_names = hdmi_pll_parents,
        .num_parents = ARRAY_SIZE(hdmi_pll_parents),
        .flags = CLK_IGNORE_UNUSED,
};

int msm_hdmi_pll_8960_init(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct hdmi_pll_8960 *pll;
        struct clk *clk;
        int i;

        /* sanity check: */
        for (i = 0; i < (ARRAY_SIZE(freqtbl) - 1); i++)
                if (WARN_ON(freqtbl[i].rate < freqtbl[i + 1].rate))
                        return -EINVAL;

        pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
        if (!pll)
                return -ENOMEM;

        pll->mmio = msm_ioremap(pdev, "hdmi_pll", "HDMI_PLL");
        if (IS_ERR(pll->mmio)) {
                DRM_DEV_ERROR(dev, "failed to map pll base\n");
                return -ENOMEM;
        }

        pll->pdev = pdev;
        pll->clk_hw.init = &pll_init;

        clk = devm_clk_register(dev, &pll->clk_hw);
        if (IS_ERR(clk)) {
                DRM_DEV_ERROR(dev, "failed to register pll clock\n");
                return -EINVAL;
        }

        return 0;
}