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![Pratyush Yadav](/assets/img/avatar_default.png)
The Cadence D-PHY can be configured in Tx (DSI) mode or Rx (CSI) mode. Both modes have a different programming sequence and share little among them. In addition, a PHY configured in Tx mode cannot be used in Rx mode and vice versa. For this reason, create a separate driver for the Rx mode to make it easier to read and maintain. Signed-off-by: Pratyush Yadav <p.yadav@ti.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Link: https://lore.kernel.org/r/20220301111621.2992275-2-p.yadav@ti.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
255 lines
6.5 KiB
C
255 lines
6.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2022 Texas Instruments Incorporated - https://www.ti.com/
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*/
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#include <linux/bitfield.h>
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#include <linux/bitops.h>
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#include <linux/io.h>
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#include <linux/iopoll.h>
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#include <linux/module.h>
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#include <linux/phy/phy.h>
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#include <linux/phy/phy-mipi-dphy.h>
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#include <linux/platform_device.h>
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#define DPHY_PMA_CMN(reg) (reg)
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#define DPHY_PCS(reg) (0xb00 + (reg))
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#define DPHY_ISO(reg) (0xc00 + (reg))
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#define DPHY_CMN_SSM DPHY_PMA_CMN(0x20)
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#define DPHY_CMN_RX_MODE_EN BIT(10)
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#define DPHY_CMN_RX_BANDGAP_TIMER_MASK GENMASK(8, 1)
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#define DPHY_CMN_SSM_EN BIT(0)
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#define DPHY_CMN_RX_BANDGAP_TIMER 0x14
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#define DPHY_BAND_CFG DPHY_PCS(0x0)
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#define DPHY_BAND_CFG_RIGHT_BAND GENMASK(9, 5)
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#define DPHY_BAND_CFG_LEFT_BAND GENMASK(4, 0)
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#define DPHY_POWER_ISLAND_EN_DATA DPHY_PCS(0x8)
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#define DPHY_POWER_ISLAND_EN_DATA_VAL 0xaaaaaaaa
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#define DPHY_POWER_ISLAND_EN_CLK DPHY_PCS(0xc)
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#define DPHY_POWER_ISLAND_EN_CLK_VAL 0xaa
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#define DPHY_ISO_CL_CTRL_L DPHY_ISO(0x10)
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#define DPHY_ISO_DL_CTRL_L0 DPHY_ISO(0x14)
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#define DPHY_ISO_DL_CTRL_L1 DPHY_ISO(0x20)
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#define DPHY_ISO_DL_CTRL_L2 DPHY_ISO(0x30)
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#define DPHY_ISO_DL_CTRL_L3 DPHY_ISO(0x3c)
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#define DPHY_ISO_LANE_READY_BIT 0
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#define DPHY_ISO_LANE_READY_TIMEOUT_MS 100UL
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#define DPHY_LANES_MIN 1
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#define DPHY_LANES_MAX 4
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struct cdns_dphy_rx {
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void __iomem *regs;
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struct device *dev;
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struct phy *phy;
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};
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struct cdns_dphy_rx_band {
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/* Rates are in Mbps. */
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unsigned int min_rate;
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unsigned int max_rate;
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};
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/* Order of bands is important since the index is the band number. */
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static const struct cdns_dphy_rx_band bands[] = {
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{ 80, 100 }, { 100, 120 }, { 120, 160 }, { 160, 200 }, { 200, 240 },
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{ 240, 280 }, { 280, 320 }, { 320, 360 }, { 360, 400 }, { 400, 480 },
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{ 480, 560 }, { 560, 640 }, { 640, 720 }, { 720, 800 }, { 800, 880 },
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{ 880, 1040 }, { 1040, 1200 }, { 1200, 1350 }, { 1350, 1500 },
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{ 1500, 1750 }, { 1750, 2000 }, { 2000, 2250 }, { 2250, 2500 }
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};
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static int cdns_dphy_rx_power_on(struct phy *phy)
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{
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struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
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/* Start RX state machine. */
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writel(DPHY_CMN_SSM_EN | DPHY_CMN_RX_MODE_EN |
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FIELD_PREP(DPHY_CMN_RX_BANDGAP_TIMER_MASK,
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DPHY_CMN_RX_BANDGAP_TIMER),
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dphy->regs + DPHY_CMN_SSM);
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return 0;
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}
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static int cdns_dphy_rx_power_off(struct phy *phy)
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{
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struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
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writel(0, dphy->regs + DPHY_CMN_SSM);
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return 0;
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}
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static int cdns_dphy_rx_get_band_ctrl(unsigned long hs_clk_rate)
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{
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unsigned int rate, i;
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rate = hs_clk_rate / 1000000UL;
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/* Since CSI-2 clock is DDR, the bit rate is twice the clock rate. */
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rate *= 2;
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if (rate < bands[0].min_rate)
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return -EOPNOTSUPP;
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for (i = 0; i < ARRAY_SIZE(bands); i++)
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if (rate < bands[i].max_rate)
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return i;
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return -EOPNOTSUPP;
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}
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static inline int cdns_dphy_rx_wait_for_bit(void __iomem *addr,
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unsigned int bit)
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{
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u32 val;
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return readl_relaxed_poll_timeout(addr, val, val & BIT(bit), 10,
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DPHY_ISO_LANE_READY_TIMEOUT_MS * 1000);
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}
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static int cdns_dphy_rx_wait_lane_ready(struct cdns_dphy_rx *dphy,
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unsigned int lanes)
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{
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static const u32 data_lane_ctrl[] = {DPHY_ISO_DL_CTRL_L0,
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DPHY_ISO_DL_CTRL_L1,
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DPHY_ISO_DL_CTRL_L2,
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DPHY_ISO_DL_CTRL_L3};
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void __iomem *reg = dphy->regs;
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unsigned int i;
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int ret;
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/* Clock lane */
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ret = cdns_dphy_rx_wait_for_bit(reg + DPHY_ISO_CL_CTRL_L,
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DPHY_ISO_LANE_READY_BIT);
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if (ret)
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return ret;
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for (i = 0; i < lanes; i++) {
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ret = cdns_dphy_rx_wait_for_bit(reg + data_lane_ctrl[i],
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DPHY_ISO_LANE_READY_BIT);
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if (ret)
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return ret;
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}
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return 0;
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}
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static int cdns_dphy_rx_configure(struct phy *phy,
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union phy_configure_opts *opts)
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{
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struct cdns_dphy_rx *dphy = phy_get_drvdata(phy);
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unsigned int reg, lanes = opts->mipi_dphy.lanes;
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int band_ctrl, ret;
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/* Data lanes. Minimum one lane is mandatory. */
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if (lanes < DPHY_LANES_MIN || lanes > DPHY_LANES_MAX)
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return -EINVAL;
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band_ctrl = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
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if (band_ctrl < 0)
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return band_ctrl;
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reg = FIELD_PREP(DPHY_BAND_CFG_LEFT_BAND, band_ctrl) |
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FIELD_PREP(DPHY_BAND_CFG_RIGHT_BAND, band_ctrl);
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writel(reg, dphy->regs + DPHY_BAND_CFG);
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/*
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* Set the required power island phase 2 time. This is mandated by DPHY
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* specs.
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*/
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reg = DPHY_POWER_ISLAND_EN_DATA_VAL;
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writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_DATA);
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reg = DPHY_POWER_ISLAND_EN_CLK_VAL;
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writel(reg, dphy->regs + DPHY_POWER_ISLAND_EN_CLK);
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ret = cdns_dphy_rx_wait_lane_ready(dphy, lanes);
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if (ret) {
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dev_err(dphy->dev, "DPHY wait for lane ready timeout\n");
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return ret;
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}
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return 0;
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}
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static int cdns_dphy_rx_validate(struct phy *phy, enum phy_mode mode,
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int submode, union phy_configure_opts *opts)
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{
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int ret;
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if (mode != PHY_MODE_MIPI_DPHY)
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return -EINVAL;
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ret = cdns_dphy_rx_get_band_ctrl(opts->mipi_dphy.hs_clk_rate);
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if (ret < 0)
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return ret;
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return phy_mipi_dphy_config_validate(&opts->mipi_dphy);
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}
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static const struct phy_ops cdns_dphy_rx_ops = {
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.power_on = cdns_dphy_rx_power_on,
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.power_off = cdns_dphy_rx_power_off,
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.configure = cdns_dphy_rx_configure,
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.validate = cdns_dphy_rx_validate,
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};
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static int cdns_dphy_rx_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct phy_provider *provider;
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struct cdns_dphy_rx *dphy;
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dphy = devm_kzalloc(dev, sizeof(*dphy), GFP_KERNEL);
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if (!dphy)
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return -ENOMEM;
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dev_set_drvdata(dev, dphy);
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dphy->dev = dev;
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dphy->regs = devm_platform_ioremap_resource(pdev, 0);
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if (IS_ERR(dphy->regs))
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return PTR_ERR(dphy->regs);
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dphy->phy = devm_phy_create(dev, NULL, &cdns_dphy_rx_ops);
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if (IS_ERR(dphy->phy)) {
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dev_err(dev, "Failed to create PHY: %ld\n", PTR_ERR(dphy->phy));
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return PTR_ERR(dphy->phy);
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}
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phy_set_drvdata(dphy->phy, dphy);
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provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
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if (IS_ERR(provider)) {
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dev_err(dev, "Failed to register PHY provider: %ld\n",
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PTR_ERR(provider));
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return PTR_ERR(provider);
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}
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return 0;
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}
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static const struct of_device_id cdns_dphy_rx_of_match[] = {
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{ .compatible = "cdns,dphy-rx" },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, cdns_dphy_rx_of_match);
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static struct platform_driver cdns_dphy_rx_platform_driver = {
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.probe = cdns_dphy_rx_probe,
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.driver = {
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.name = "cdns-mipi-dphy-rx",
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.of_match_table = cdns_dphy_rx_of_match,
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},
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};
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module_platform_driver(cdns_dphy_rx_platform_driver);
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MODULE_AUTHOR("Pratyush Yadav <p.yadav@ti.com>");
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MODULE_DESCRIPTION("Cadence D-PHY Rx Driver");
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MODULE_LICENSE("GPL");
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