blob: a1f57af6acfb0bb927214f61693c1798b2995cb7 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Driver for Synopsys DesignWare Cores Mobile Storage Host Controller
*
* Copyright (C) 2018 Synaptics Incorporated
*
* Author: Jisheng Zhang <jszhang@kernel.org>
*/
#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/dma-mapping.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/reset.h>
#include <linux/sizes.h>
#include "sdhci-pltfm.h"
#define SDHCI_DWCMSHC_ARG2_STUFF GENMASK(31, 16)
/* DWCMSHC specific Mode Select value */
#define DWCMSHC_CTRL_HS400 0x7
/* DWC IP vendor area 1 pointer */
#define DWCMSHC_P_VENDOR_AREA1 0xe8
#define DWCMSHC_AREA1_MASK GENMASK(11, 0)
/* Offset inside the vendor area 1 */
#define DWCMSHC_HOST_CTRL3 0x8
#define DWCMSHC_EMMC_CONTROL 0x2c
#define DWCMSHC_CARD_IS_EMMC BIT(0)
#define DWCMSHC_ENHANCED_STROBE BIT(8)
#define DWCMSHC_EMMC_ATCTRL 0x40
/* Tuning and auto-tuning fields in AT_CTRL_R control register */
#define AT_CTRL_AT_EN BIT(0) /* autotuning is enabled */
#define AT_CTRL_CI_SEL BIT(1) /* interval to drive center phase select */
#define AT_CTRL_SWIN_TH_EN BIT(2) /* sampling window threshold enable */
#define AT_CTRL_RPT_TUNE_ERR BIT(3) /* enable reporting framing errors */
#define AT_CTRL_SW_TUNE_EN BIT(4) /* enable software managed tuning */
#define AT_CTRL_WIN_EDGE_SEL_MASK GENMASK(11, 8) /* bits [11:8] */
#define AT_CTRL_WIN_EDGE_SEL 0xf /* sampling window edge select */
#define AT_CTRL_TUNE_CLK_STOP_EN BIT(16) /* clocks stopped during phase code change */
#define AT_CTRL_PRE_CHANGE_DLY_MASK GENMASK(18, 17) /* bits [18:17] */
#define AT_CTRL_PRE_CHANGE_DLY 0x1 /* 2-cycle latency */
#define AT_CTRL_POST_CHANGE_DLY_MASK GENMASK(20, 19) /* bits [20:19] */
#define AT_CTRL_POST_CHANGE_DLY 0x3 /* 4-cycle latency */
#define AT_CTRL_SWIN_TH_VAL_MASK GENMASK(31, 24) /* bits [31:24] */
#define AT_CTRL_SWIN_TH_VAL 0x9 /* sampling window threshold */
/* Rockchip specific Registers */
#define DWCMSHC_EMMC_DLL_CTRL 0x800
#define DWCMSHC_EMMC_DLL_RXCLK 0x804
#define DWCMSHC_EMMC_DLL_TXCLK 0x808
#define DWCMSHC_EMMC_DLL_STRBIN 0x80c
#define DECMSHC_EMMC_DLL_CMDOUT 0x810
#define DWCMSHC_EMMC_DLL_STATUS0 0x840
#define DWCMSHC_EMMC_DLL_START BIT(0)
#define DWCMSHC_EMMC_DLL_LOCKED BIT(8)
#define DWCMSHC_EMMC_DLL_TIMEOUT BIT(9)
#define DWCMSHC_EMMC_DLL_RXCLK_SRCSEL 29
#define DWCMSHC_EMMC_DLL_START_POINT 16
#define DWCMSHC_EMMC_DLL_INC 8
#define DWCMSHC_EMMC_DLL_BYPASS BIT(24)
#define DWCMSHC_EMMC_DLL_DLYENA BIT(27)
#define DLL_TXCLK_TAPNUM_DEFAULT 0x10
#define DLL_TXCLK_TAPNUM_90_DEGREES 0xA
#define DLL_TXCLK_TAPNUM_FROM_SW BIT(24)
#define DLL_STRBIN_TAPNUM_DEFAULT 0x8
#define DLL_STRBIN_TAPNUM_FROM_SW BIT(24)
#define DLL_STRBIN_DELAY_NUM_SEL BIT(26)
#define DLL_STRBIN_DELAY_NUM_OFFSET 16
#define DLL_STRBIN_DELAY_NUM_DEFAULT 0x16
#define DLL_RXCLK_NO_INVERTER 1
#define DLL_RXCLK_INVERTER 0
#define DLL_CMDOUT_TAPNUM_90_DEGREES 0x8
#define DLL_RXCLK_ORI_GATE BIT(31)
#define DLL_CMDOUT_TAPNUM_FROM_SW BIT(24)
#define DLL_CMDOUT_SRC_CLK_NEG BIT(28)
#define DLL_CMDOUT_EN_SRC_CLK_NEG BIT(29)
#define DLL_LOCK_WO_TMOUT(x) \
((((x) & DWCMSHC_EMMC_DLL_LOCKED) == DWCMSHC_EMMC_DLL_LOCKED) && \
(((x) & DWCMSHC_EMMC_DLL_TIMEOUT) == 0))
#define RK35xx_MAX_CLKS 3
/* PHY register area pointer */
#define DWC_MSHC_PTR_PHY_R 0x300
/* PHY general configuration */
#define PHY_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x00)
#define PHY_CNFG_RSTN_DEASSERT 0x1 /* Deassert PHY reset */
#define PHY_CNFG_PAD_SP_MASK GENMASK(19, 16) /* bits [19:16] */
#define PHY_CNFG_PAD_SP 0x0c /* PMOS TX drive strength */
#define PHY_CNFG_PAD_SN_MASK GENMASK(23, 20) /* bits [23:20] */
#define PHY_CNFG_PAD_SN 0x0c /* NMOS TX drive strength */
/* PHY command/response pad settings */
#define PHY_CMDPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x04)
/* PHY data pad settings */
#define PHY_DATAPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x06)
/* PHY clock pad settings */
#define PHY_CLKPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x08)
/* PHY strobe pad settings */
#define PHY_STBPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x0a)
/* PHY reset pad settings */
#define PHY_RSTNPAD_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x0c)
/* Bitfields are common for all pad settings */
#define PHY_PAD_RXSEL_1V8 0x1 /* Receiver type select for 1.8V */
#define PHY_PAD_RXSEL_3V3 0x2 /* Receiver type select for 3.3V */
#define PHY_PAD_WEAKPULL_MASK GENMASK(4, 3) /* bits [4:3] */
#define PHY_PAD_WEAKPULL_PULLUP 0x1 /* Weak pull up enabled */
#define PHY_PAD_WEAKPULL_PULLDOWN 0x2 /* Weak pull down enabled */
#define PHY_PAD_TXSLEW_CTRL_P_MASK GENMASK(8, 5) /* bits [8:5] */
#define PHY_PAD_TXSLEW_CTRL_P 0x3 /* Slew control for P-Type pad TX */
#define PHY_PAD_TXSLEW_CTRL_N_MASK GENMASK(12, 9) /* bits [12:9] */
#define PHY_PAD_TXSLEW_CTRL_N 0x3 /* Slew control for N-Type pad TX */
/* PHY CLK delay line settings */
#define PHY_SDCLKDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x1d)
#define PHY_SDCLKDL_CNFG_UPDATE BIT(4) /* set before writing to SDCLKDL_DC */
/* PHY CLK delay line delay code */
#define PHY_SDCLKDL_DC_R (DWC_MSHC_PTR_PHY_R + 0x1e)
#define PHY_SDCLKDL_DC_INITIAL 0x40 /* initial delay code */
#define PHY_SDCLKDL_DC_DEFAULT 0x32 /* default delay code */
#define PHY_SDCLKDL_DC_HS400 0x18 /* delay code for HS400 mode */
/* PHY drift_cclk_rx delay line configuration setting */
#define PHY_ATDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x21)
#define PHY_ATDL_CNFG_INPSEL_MASK GENMASK(3, 2) /* bits [3:2] */
#define PHY_ATDL_CNFG_INPSEL 0x3 /* delay line input source */
/* PHY DLL control settings */
#define PHY_DLL_CTRL_R (DWC_MSHC_PTR_PHY_R + 0x24)
#define PHY_DLL_CTRL_DISABLE 0x0 /* PHY DLL is enabled */
#define PHY_DLL_CTRL_ENABLE 0x1 /* PHY DLL is disabled */
/* PHY DLL configuration register 1 */
#define PHY_DLL_CNFG1_R (DWC_MSHC_PTR_PHY_R + 0x25)
#define PHY_DLL_CNFG1_SLVDLY_MASK GENMASK(5, 4) /* bits [5:4] */
#define PHY_DLL_CNFG1_SLVDLY 0x2 /* DLL slave update delay input */
#define PHY_DLL_CNFG1_WAITCYCLE 0x5 /* DLL wait cycle input */
/* PHY DLL configuration register 2 */
#define PHY_DLL_CNFG2_R (DWC_MSHC_PTR_PHY_R + 0x26)
#define PHY_DLL_CNFG2_JUMPSTEP 0xa /* DLL jump step input */
/* PHY DLL master and slave delay line configuration settings */
#define PHY_DLLDL_CNFG_R (DWC_MSHC_PTR_PHY_R + 0x28)
#define PHY_DLLDL_CNFG_SLV_INPSEL_MASK GENMASK(6, 5) /* bits [6:5] */
#define PHY_DLLDL_CNFG_SLV_INPSEL 0x3 /* clock source select for slave DL */
#define FLAG_IO_FIXED_1V8 BIT(0)
#define BOUNDARY_OK(addr, len) \
((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))
enum dwcmshc_rk_type {
DWCMSHC_RK3568,
DWCMSHC_RK3588,
};
struct rk35xx_priv {
/* Rockchip specified optional clocks */
struct clk_bulk_data rockchip_clks[RK35xx_MAX_CLKS];
struct reset_control *reset;
enum dwcmshc_rk_type devtype;
u8 txclk_tapnum;
};
struct dwcmshc_priv {
struct clk *bus_clk;
int vendor_specific_area1; /* P_VENDOR_SPECIFIC_AREA reg */
void *priv; /* pointer to SoC private stuff */
u16 delay_line;
u16 flags;
};
/*
* If DMA addr spans 128MB boundary, we split the DMA transfer into two
* so that each DMA transfer doesn't exceed the boundary.
*/
static void dwcmshc_adma_write_desc(struct sdhci_host *host, void **desc,
dma_addr_t addr, int len, unsigned int cmd)
{
int tmplen, offset;
if (likely(!len || BOUNDARY_OK(addr, len))) {
sdhci_adma_write_desc(host, desc, addr, len, cmd);
return;
}
offset = addr & (SZ_128M - 1);
tmplen = SZ_128M - offset;
sdhci_adma_write_desc(host, desc, addr, tmplen, cmd);
addr += tmplen;
len -= tmplen;
sdhci_adma_write_desc(host, desc, addr, len, cmd);
}
static unsigned int dwcmshc_get_max_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
if (pltfm_host->clk)
return sdhci_pltfm_clk_get_max_clock(host);
else
return pltfm_host->clock;
}
static unsigned int rk35xx_get_max_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
return clk_round_rate(pltfm_host->clk, ULONG_MAX);
}
static void dwcmshc_check_auto_cmd23(struct mmc_host *mmc,
struct mmc_request *mrq)
{
struct sdhci_host *host = mmc_priv(mmc);
/*
* No matter V4 is enabled or not, ARGUMENT2 register is 32-bit
* block count register which doesn't support stuff bits of
* CMD23 argument on dwcmsch host controller.
*/
if (mrq->sbc && (mrq->sbc->arg & SDHCI_DWCMSHC_ARG2_STUFF))
host->flags &= ~SDHCI_AUTO_CMD23;
else
host->flags |= SDHCI_AUTO_CMD23;
}
static void dwcmshc_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
dwcmshc_check_auto_cmd23(mmc, mrq);
sdhci_request(mmc, mrq);
}
static void dwcmshc_phy_1_8v_init(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
u32 val;
/* deassert phy reset & set tx drive strength */
val = PHY_CNFG_RSTN_DEASSERT;
val |= FIELD_PREP(PHY_CNFG_PAD_SP_MASK, PHY_CNFG_PAD_SP);
val |= FIELD_PREP(PHY_CNFG_PAD_SN_MASK, PHY_CNFG_PAD_SN);
sdhci_writel(host, val, PHY_CNFG_R);
/* disable delay line */
sdhci_writeb(host, PHY_SDCLKDL_CNFG_UPDATE, PHY_SDCLKDL_CNFG_R);
/* set delay line */
sdhci_writeb(host, priv->delay_line, PHY_SDCLKDL_DC_R);
sdhci_writeb(host, PHY_DLL_CNFG2_JUMPSTEP, PHY_DLL_CNFG2_R);
/* enable delay lane */
val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
val &= ~(PHY_SDCLKDL_CNFG_UPDATE);
sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
/* configure phy pads */
val = PHY_PAD_RXSEL_1V8;
val |= FIELD_PREP(PHY_PAD_WEAKPULL_MASK, PHY_PAD_WEAKPULL_PULLUP);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, PHY_PAD_TXSLEW_CTRL_P);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, PHY_PAD_TXSLEW_CTRL_N);
sdhci_writew(host, val, PHY_CMDPAD_CNFG_R);
sdhci_writew(host, val, PHY_DATAPAD_CNFG_R);
sdhci_writew(host, val, PHY_RSTNPAD_CNFG_R);
val = FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, PHY_PAD_TXSLEW_CTRL_P);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, PHY_PAD_TXSLEW_CTRL_N);
sdhci_writew(host, val, PHY_CLKPAD_CNFG_R);
val = PHY_PAD_RXSEL_1V8;
val |= FIELD_PREP(PHY_PAD_WEAKPULL_MASK, PHY_PAD_WEAKPULL_PULLDOWN);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, PHY_PAD_TXSLEW_CTRL_P);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, PHY_PAD_TXSLEW_CTRL_N);
sdhci_writew(host, val, PHY_STBPAD_CNFG_R);
/* enable data strobe mode */
sdhci_writeb(host, FIELD_PREP(PHY_DLLDL_CNFG_SLV_INPSEL_MASK, PHY_DLLDL_CNFG_SLV_INPSEL),
PHY_DLLDL_CNFG_R);
/* enable phy dll */
sdhci_writeb(host, PHY_DLL_CTRL_ENABLE, PHY_DLL_CTRL_R);
}
static void dwcmshc_phy_3_3v_init(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
u32 val;
/* deassert phy reset & set tx drive strength */
val = PHY_CNFG_RSTN_DEASSERT;
val |= FIELD_PREP(PHY_CNFG_PAD_SP_MASK, PHY_CNFG_PAD_SP);
val |= FIELD_PREP(PHY_CNFG_PAD_SN_MASK, PHY_CNFG_PAD_SN);
sdhci_writel(host, val, PHY_CNFG_R);
/* disable delay line */
sdhci_writeb(host, PHY_SDCLKDL_CNFG_UPDATE, PHY_SDCLKDL_CNFG_R);
/* set delay line */
sdhci_writeb(host, priv->delay_line, PHY_SDCLKDL_DC_R);
sdhci_writeb(host, PHY_DLL_CNFG2_JUMPSTEP, PHY_DLL_CNFG2_R);
/* enable delay lane */
val = sdhci_readb(host, PHY_SDCLKDL_CNFG_R);
val &= ~(PHY_SDCLKDL_CNFG_UPDATE);
sdhci_writeb(host, val, PHY_SDCLKDL_CNFG_R);
/* configure phy pads */
val = PHY_PAD_RXSEL_3V3;
val |= FIELD_PREP(PHY_PAD_WEAKPULL_MASK, PHY_PAD_WEAKPULL_PULLUP);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, PHY_PAD_TXSLEW_CTRL_P);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, PHY_PAD_TXSLEW_CTRL_N);
sdhci_writew(host, val, PHY_CMDPAD_CNFG_R);
sdhci_writew(host, val, PHY_DATAPAD_CNFG_R);
sdhci_writew(host, val, PHY_RSTNPAD_CNFG_R);
val = FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, PHY_PAD_TXSLEW_CTRL_P);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, PHY_PAD_TXSLEW_CTRL_N);
sdhci_writew(host, val, PHY_CLKPAD_CNFG_R);
val = PHY_PAD_RXSEL_3V3;
val |= FIELD_PREP(PHY_PAD_WEAKPULL_MASK, PHY_PAD_WEAKPULL_PULLDOWN);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_P_MASK, PHY_PAD_TXSLEW_CTRL_P);
val |= FIELD_PREP(PHY_PAD_TXSLEW_CTRL_N_MASK, PHY_PAD_TXSLEW_CTRL_N);
sdhci_writew(host, val, PHY_STBPAD_CNFG_R);
/* enable phy dll */
sdhci_writeb(host, PHY_DLL_CTRL_ENABLE, PHY_DLL_CTRL_R);
}
static void th1520_sdhci_set_phy(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
u32 emmc_caps = MMC_CAP2_NO_SD | MMC_CAP2_NO_SDIO;
u16 emmc_ctrl;
/* Before power on, set PHY configs */
if (priv->flags & FLAG_IO_FIXED_1V8)
dwcmshc_phy_1_8v_init(host);
else
dwcmshc_phy_3_3v_init(host);
if ((host->mmc->caps2 & emmc_caps) == emmc_caps) {
emmc_ctrl = sdhci_readw(host, priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL);
emmc_ctrl |= DWCMSHC_CARD_IS_EMMC;
sdhci_writew(host, emmc_ctrl, priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL);
}
sdhci_writeb(host, FIELD_PREP(PHY_DLL_CNFG1_SLVDLY_MASK, PHY_DLL_CNFG1_SLVDLY) |
PHY_DLL_CNFG1_WAITCYCLE, PHY_DLL_CNFG1_R);
}
static void dwcmshc_set_uhs_signaling(struct sdhci_host *host,
unsigned int timing)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
u16 ctrl, ctrl_2;
ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
/* Select Bus Speed Mode for host */
ctrl_2 &= ~SDHCI_CTRL_UHS_MASK;
if ((timing == MMC_TIMING_MMC_HS200) ||
(timing == MMC_TIMING_UHS_SDR104))
ctrl_2 |= SDHCI_CTRL_UHS_SDR104;
else if (timing == MMC_TIMING_UHS_SDR12)
ctrl_2 |= SDHCI_CTRL_UHS_SDR12;
else if ((timing == MMC_TIMING_UHS_SDR25) ||
(timing == MMC_TIMING_MMC_HS))
ctrl_2 |= SDHCI_CTRL_UHS_SDR25;
else if (timing == MMC_TIMING_UHS_SDR50)
ctrl_2 |= SDHCI_CTRL_UHS_SDR50;
else if ((timing == MMC_TIMING_UHS_DDR50) ||
(timing == MMC_TIMING_MMC_DDR52))
ctrl_2 |= SDHCI_CTRL_UHS_DDR50;
else if (timing == MMC_TIMING_MMC_HS400) {
/* set CARD_IS_EMMC bit to enable Data Strobe for HS400 */
ctrl = sdhci_readw(host, priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL);
ctrl |= DWCMSHC_CARD_IS_EMMC;
sdhci_writew(host, ctrl, priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL);
ctrl_2 |= DWCMSHC_CTRL_HS400;
}
if (priv->flags & FLAG_IO_FIXED_1V8)
ctrl_2 |= SDHCI_CTRL_VDD_180;
sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
}
static void th1520_set_uhs_signaling(struct sdhci_host *host,
unsigned int timing)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
dwcmshc_set_uhs_signaling(host, timing);
if (timing == MMC_TIMING_MMC_HS400)
priv->delay_line = PHY_SDCLKDL_DC_HS400;
else
sdhci_writeb(host, 0, PHY_DLLDL_CNFG_R);
th1520_sdhci_set_phy(host);
}
static void dwcmshc_hs400_enhanced_strobe(struct mmc_host *mmc,
struct mmc_ios *ios)
{
u32 vendor;
struct sdhci_host *host = mmc_priv(mmc);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
int reg = priv->vendor_specific_area1 + DWCMSHC_EMMC_CONTROL;
vendor = sdhci_readl(host, reg);
if (ios->enhanced_strobe)
vendor |= DWCMSHC_ENHANCED_STROBE;
else
vendor &= ~DWCMSHC_ENHANCED_STROBE;
sdhci_writel(host, vendor, reg);
}
static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host);
struct rk35xx_priv *priv = dwc_priv->priv;
u8 txclk_tapnum = DLL_TXCLK_TAPNUM_DEFAULT;
u32 extra, reg;
int err;
host->mmc->actual_clock = 0;
if (clock == 0) {
/* Disable interface clock at initial state. */
sdhci_set_clock(host, clock);
return;
}
/* Rockchip platform only support 375KHz for identify mode */
if (clock <= 400000)
clock = 375000;
err = clk_set_rate(pltfm_host->clk, clock);
if (err)
dev_err(mmc_dev(host->mmc), "fail to set clock %d", clock);
sdhci_set_clock(host, clock);
/* Disable cmd conflict check */
reg = dwc_priv->vendor_specific_area1 + DWCMSHC_HOST_CTRL3;
extra = sdhci_readl(host, reg);
extra &= ~BIT(0);
sdhci_writel(host, extra, reg);
if (clock <= 52000000) {
/*
* Disable DLL and reset both of sample and drive clock.
* The bypass bit and start bit need to be set if DLL is not locked.
*/
sdhci_writel(host, DWCMSHC_EMMC_DLL_BYPASS | DWCMSHC_EMMC_DLL_START, DWCMSHC_EMMC_DLL_CTRL);
sdhci_writel(host, DLL_RXCLK_ORI_GATE, DWCMSHC_EMMC_DLL_RXCLK);
sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_TXCLK);
sdhci_writel(host, 0, DECMSHC_EMMC_DLL_CMDOUT);
/*
* Before switching to hs400es mode, the driver will enable
* enhanced strobe first. PHY needs to configure the parameters
* of enhanced strobe first.
*/
extra = DWCMSHC_EMMC_DLL_DLYENA |
DLL_STRBIN_DELAY_NUM_SEL |
DLL_STRBIN_DELAY_NUM_DEFAULT << DLL_STRBIN_DELAY_NUM_OFFSET;
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN);
return;
}
/* Reset DLL */
sdhci_writel(host, BIT(1), DWCMSHC_EMMC_DLL_CTRL);
udelay(1);
sdhci_writel(host, 0x0, DWCMSHC_EMMC_DLL_CTRL);
/*
* We shouldn't set DLL_RXCLK_NO_INVERTER for identify mode but
* we must set it in higher speed mode.
*/
extra = DWCMSHC_EMMC_DLL_DLYENA;
if (priv->devtype == DWCMSHC_RK3568)
extra |= DLL_RXCLK_NO_INVERTER << DWCMSHC_EMMC_DLL_RXCLK_SRCSEL;
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_RXCLK);
/* Init DLL settings */
extra = 0x5 << DWCMSHC_EMMC_DLL_START_POINT |
0x2 << DWCMSHC_EMMC_DLL_INC |
DWCMSHC_EMMC_DLL_START;
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_CTRL);
err = readl_poll_timeout(host->ioaddr + DWCMSHC_EMMC_DLL_STATUS0,
extra, DLL_LOCK_WO_TMOUT(extra), 1,
500 * USEC_PER_MSEC);
if (err) {
dev_err(mmc_dev(host->mmc), "DLL lock timeout!\n");
return;
}
extra = 0x1 << 16 | /* tune clock stop en */
0x3 << 17 | /* pre-change delay */
0x3 << 19; /* post-change delay */
sdhci_writel(host, extra, dwc_priv->vendor_specific_area1 + DWCMSHC_EMMC_ATCTRL);
if (host->mmc->ios.timing == MMC_TIMING_MMC_HS200 ||
host->mmc->ios.timing == MMC_TIMING_MMC_HS400)
txclk_tapnum = priv->txclk_tapnum;
if ((priv->devtype == DWCMSHC_RK3588) && host->mmc->ios.timing == MMC_TIMING_MMC_HS400) {
txclk_tapnum = DLL_TXCLK_TAPNUM_90_DEGREES;
extra = DLL_CMDOUT_SRC_CLK_NEG |
DLL_CMDOUT_EN_SRC_CLK_NEG |
DWCMSHC_EMMC_DLL_DLYENA |
DLL_CMDOUT_TAPNUM_90_DEGREES |
DLL_CMDOUT_TAPNUM_FROM_SW;
sdhci_writel(host, extra, DECMSHC_EMMC_DLL_CMDOUT);
}
extra = DWCMSHC_EMMC_DLL_DLYENA |
DLL_TXCLK_TAPNUM_FROM_SW |
DLL_RXCLK_NO_INVERTER << DWCMSHC_EMMC_DLL_RXCLK_SRCSEL |
txclk_tapnum;
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_TXCLK);
extra = DWCMSHC_EMMC_DLL_DLYENA |
DLL_STRBIN_TAPNUM_DEFAULT |
DLL_STRBIN_TAPNUM_FROM_SW;
sdhci_writel(host, extra, DWCMSHC_EMMC_DLL_STRBIN);
}
static void rk35xx_sdhci_reset(struct sdhci_host *host, u8 mask)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *dwc_priv = sdhci_pltfm_priv(pltfm_host);
struct rk35xx_priv *priv = dwc_priv->priv;
if (mask & SDHCI_RESET_ALL && priv->reset) {
reset_control_assert(priv->reset);
udelay(1);
reset_control_deassert(priv->reset);
}
sdhci_reset(host, mask);
}
static int th1520_execute_tuning(struct sdhci_host *host, u32 opcode)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
u32 val = 0;
if (host->flags & SDHCI_HS400_TUNING)
return 0;
sdhci_writeb(host, FIELD_PREP(PHY_ATDL_CNFG_INPSEL_MASK, PHY_ATDL_CNFG_INPSEL),
PHY_ATDL_CNFG_R);
val = sdhci_readl(host, priv->vendor_specific_area1 + DWCMSHC_EMMC_ATCTRL);
/*
* configure tuning settings:
* - center phase select code driven in block gap interval
* - disable reporting of framing errors
* - disable software managed tuning
* - disable user selection of sampling window edges,
* instead tuning calculated edges are used
*/
val &= ~(AT_CTRL_CI_SEL | AT_CTRL_RPT_TUNE_ERR | AT_CTRL_SW_TUNE_EN |
FIELD_PREP(AT_CTRL_WIN_EDGE_SEL_MASK, AT_CTRL_WIN_EDGE_SEL));
/*
* configure tuning settings:
* - enable auto-tuning
* - enable sampling window threshold
* - stop clocks during phase code change
* - set max latency in cycles between tx and rx clocks
* - set max latency in cycles to switch output phase
* - set max sampling window threshold value
*/
val |= AT_CTRL_AT_EN | AT_CTRL_SWIN_TH_EN | AT_CTRL_TUNE_CLK_STOP_EN;
val |= FIELD_PREP(AT_CTRL_PRE_CHANGE_DLY_MASK, AT_CTRL_PRE_CHANGE_DLY);
val |= FIELD_PREP(AT_CTRL_POST_CHANGE_DLY_MASK, AT_CTRL_POST_CHANGE_DLY);
val |= FIELD_PREP(AT_CTRL_SWIN_TH_VAL_MASK, AT_CTRL_SWIN_TH_VAL);
sdhci_writel(host, val, priv->vendor_specific_area1 + DWCMSHC_EMMC_ATCTRL);
val = sdhci_readl(host, priv->vendor_specific_area1 + DWCMSHC_EMMC_ATCTRL);
/* perform tuning */
sdhci_start_tuning(host);
host->tuning_err = __sdhci_execute_tuning(host, opcode);
if (host->tuning_err) {
/* disable auto-tuning upon tuning error */
val &= ~AT_CTRL_AT_EN;
sdhci_writel(host, val, priv->vendor_specific_area1 + DWCMSHC_EMMC_ATCTRL);
dev_err(mmc_dev(host->mmc), "tuning failed: %d\n", host->tuning_err);
return -EIO;
}
sdhci_end_tuning(host);
return 0;
}
static void th1520_sdhci_reset(struct sdhci_host *host, u8 mask)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
u16 ctrl_2;
sdhci_reset(host, mask);
if (priv->flags & FLAG_IO_FIXED_1V8) {
ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
if (!(ctrl_2 & SDHCI_CTRL_VDD_180)) {
ctrl_2 |= SDHCI_CTRL_VDD_180;
sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
}
}
}
static const struct sdhci_ops sdhci_dwcmshc_ops = {
.set_clock = sdhci_set_clock,
.set_bus_width = sdhci_set_bus_width,
.set_uhs_signaling = dwcmshc_set_uhs_signaling,
.get_max_clock = dwcmshc_get_max_clock,
.reset = sdhci_reset,
.adma_write_desc = dwcmshc_adma_write_desc,
};
static const struct sdhci_ops sdhci_dwcmshc_rk35xx_ops = {
.set_clock = dwcmshc_rk3568_set_clock,
.set_bus_width = sdhci_set_bus_width,
.set_uhs_signaling = dwcmshc_set_uhs_signaling,
.get_max_clock = rk35xx_get_max_clock,
.reset = rk35xx_sdhci_reset,
.adma_write_desc = dwcmshc_adma_write_desc,
};
static const struct sdhci_ops sdhci_dwcmshc_th1520_ops = {
.set_clock = sdhci_set_clock,
.set_bus_width = sdhci_set_bus_width,
.set_uhs_signaling = th1520_set_uhs_signaling,
.get_max_clock = dwcmshc_get_max_clock,
.reset = th1520_sdhci_reset,
.adma_write_desc = dwcmshc_adma_write_desc,
.voltage_switch = dwcmshc_phy_1_8v_init,
.platform_execute_tuning = &th1520_execute_tuning,
};
static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
.ops = &sdhci_dwcmshc_ops,
.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
};
#ifdef CONFIG_ACPI
static const struct sdhci_pltfm_data sdhci_dwcmshc_bf3_pdata = {
.ops = &sdhci_dwcmshc_ops,
.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
SDHCI_QUIRK2_ACMD23_BROKEN,
};
#endif
static const struct sdhci_pltfm_data sdhci_dwcmshc_rk35xx_pdata = {
.ops = &sdhci_dwcmshc_rk35xx_ops,
.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
SDHCI_QUIRK_BROKEN_TIMEOUT_VAL,
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN |
SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
};
static const struct sdhci_pltfm_data sdhci_dwcmshc_th1520_pdata = {
.ops = &sdhci_dwcmshc_th1520_ops,
.quirks = SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN,
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
};
static int dwcmshc_rk35xx_init(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
{
int err;
struct rk35xx_priv *priv = dwc_priv->priv;
priv->reset = devm_reset_control_array_get_optional_exclusive(mmc_dev(host->mmc));
if (IS_ERR(priv->reset)) {
err = PTR_ERR(priv->reset);
dev_err(mmc_dev(host->mmc), "failed to get reset control %d\n", err);
return err;
}
priv->rockchip_clks[0].id = "axi";
priv->rockchip_clks[1].id = "block";
priv->rockchip_clks[2].id = "timer";
err = devm_clk_bulk_get_optional(mmc_dev(host->mmc), RK35xx_MAX_CLKS,
priv->rockchip_clks);
if (err) {
dev_err(mmc_dev(host->mmc), "failed to get clocks %d\n", err);
return err;
}
err = clk_bulk_prepare_enable(RK35xx_MAX_CLKS, priv->rockchip_clks);
if (err) {
dev_err(mmc_dev(host->mmc), "failed to enable clocks %d\n", err);
return err;
}
if (of_property_read_u8(mmc_dev(host->mmc)->of_node, "rockchip,txclk-tapnum",
&priv->txclk_tapnum))
priv->txclk_tapnum = DLL_TXCLK_TAPNUM_DEFAULT;
/* Disable cmd conflict check */
sdhci_writel(host, 0x0, dwc_priv->vendor_specific_area1 + DWCMSHC_HOST_CTRL3);
/* Reset previous settings */
sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_TXCLK);
sdhci_writel(host, 0, DWCMSHC_EMMC_DLL_STRBIN);
return 0;
}
static void dwcmshc_rk35xx_postinit(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
{
/*
* Don't support highspeed bus mode with low clk speed as we
* cannot use DLL for this condition.
*/
if (host->mmc->f_max <= 52000000) {
dev_info(mmc_dev(host->mmc), "Disabling HS200/HS400, frequency too low (%d)\n",
host->mmc->f_max);
host->mmc->caps2 &= ~(MMC_CAP2_HS200 | MMC_CAP2_HS400);
host->mmc->caps &= ~(MMC_CAP_3_3V_DDR | MMC_CAP_1_8V_DDR);
}
}
static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
{
.compatible = "rockchip,rk3588-dwcmshc",
.data = &sdhci_dwcmshc_rk35xx_pdata,
},
{
.compatible = "rockchip,rk3568-dwcmshc",
.data = &sdhci_dwcmshc_rk35xx_pdata,
},
{
.compatible = "snps,dwcmshc-sdhci",
.data = &sdhci_dwcmshc_pdata,
},
{
.compatible = "thead,th1520-dwcmshc",
.data = &sdhci_dwcmshc_th1520_pdata,
},
{},
};
MODULE_DEVICE_TABLE(of, sdhci_dwcmshc_dt_ids);
#ifdef CONFIG_ACPI
static const struct acpi_device_id sdhci_dwcmshc_acpi_ids[] = {
{
.id = "MLNXBF30",
.driver_data = (kernel_ulong_t)&sdhci_dwcmshc_bf3_pdata,
},
{}
};
MODULE_DEVICE_TABLE(acpi, sdhci_dwcmshc_acpi_ids);
#endif
static int dwcmshc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct sdhci_pltfm_host *pltfm_host;
struct sdhci_host *host;
struct dwcmshc_priv *priv;
struct rk35xx_priv *rk_priv = NULL;
const struct sdhci_pltfm_data *pltfm_data;
int err;
u32 extra;
pltfm_data = device_get_match_data(&pdev->dev);
if (!pltfm_data) {
dev_err(&pdev->dev, "Error: No device match data found\n");
return -ENODEV;
}
host = sdhci_pltfm_init(pdev, pltfm_data,
sizeof(struct dwcmshc_priv));
if (IS_ERR(host))
return PTR_ERR(host);
/*
* extra adma table cnt for cross 128M boundary handling.
*/
extra = DIV_ROUND_UP_ULL(dma_get_required_mask(dev), SZ_128M);
if (extra > SDHCI_MAX_SEGS)
extra = SDHCI_MAX_SEGS;
host->adma_table_cnt += extra;
pltfm_host = sdhci_priv(host);
priv = sdhci_pltfm_priv(pltfm_host);
if (dev->of_node) {
pltfm_host->clk = devm_clk_get(dev, "core");
if (IS_ERR(pltfm_host->clk)) {
err = PTR_ERR(pltfm_host->clk);
dev_err(dev, "failed to get core clk: %d\n", err);
goto free_pltfm;
}
err = clk_prepare_enable(pltfm_host->clk);
if (err)
goto free_pltfm;
priv->bus_clk = devm_clk_get(dev, "bus");
if (!IS_ERR(priv->bus_clk))
clk_prepare_enable(priv->bus_clk);
}
err = mmc_of_parse(host->mmc);
if (err)
goto err_clk;
sdhci_get_of_property(pdev);
priv->vendor_specific_area1 =
sdhci_readl(host, DWCMSHC_P_VENDOR_AREA1) & DWCMSHC_AREA1_MASK;
host->mmc_host_ops.request = dwcmshc_request;
host->mmc_host_ops.hs400_enhanced_strobe = dwcmshc_hs400_enhanced_strobe;
if (pltfm_data == &sdhci_dwcmshc_rk35xx_pdata) {
rk_priv = devm_kzalloc(&pdev->dev, sizeof(struct rk35xx_priv), GFP_KERNEL);
if (!rk_priv) {
err = -ENOMEM;
goto err_clk;
}
if (of_device_is_compatible(pdev->dev.of_node, "rockchip,rk3588-dwcmshc"))
rk_priv->devtype = DWCMSHC_RK3588;
else
rk_priv->devtype = DWCMSHC_RK3568;
priv->priv = rk_priv;
err = dwcmshc_rk35xx_init(host, priv);
if (err)
goto err_clk;
}
if (pltfm_data == &sdhci_dwcmshc_th1520_pdata) {
priv->delay_line = PHY_SDCLKDL_DC_DEFAULT;
if (device_property_read_bool(dev, "mmc-ddr-1_8v") ||
device_property_read_bool(dev, "mmc-hs200-1_8v") ||
device_property_read_bool(dev, "mmc-hs400-1_8v"))
priv->flags |= FLAG_IO_FIXED_1V8;
else
priv->flags &= ~FLAG_IO_FIXED_1V8;
/*
* start_signal_voltage_switch() will try 3.3V first
* then 1.8V. Use SDHCI_SIGNALING_180 rather than
* SDHCI_SIGNALING_330 to avoid setting voltage to 3.3V
* in sdhci_start_signal_voltage_switch().
*/
if (priv->flags & FLAG_IO_FIXED_1V8) {
host->flags &= ~SDHCI_SIGNALING_330;
host->flags |= SDHCI_SIGNALING_180;
}
sdhci_enable_v4_mode(host);
}
#ifdef CONFIG_ACPI
if (pltfm_data == &sdhci_dwcmshc_bf3_pdata)
sdhci_enable_v4_mode(host);
#endif
host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
pm_runtime_get_noresume(dev);
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
err = sdhci_setup_host(host);
if (err)
goto err_rpm;
if (rk_priv)
dwcmshc_rk35xx_postinit(host, priv);
err = __sdhci_add_host(host);
if (err)
goto err_setup_host;
pm_runtime_put(dev);
return 0;
err_setup_host:
sdhci_cleanup_host(host);
err_rpm:
pm_runtime_disable(dev);
pm_runtime_put_noidle(dev);
err_clk:
clk_disable_unprepare(pltfm_host->clk);
clk_disable_unprepare(priv->bus_clk);
if (rk_priv)
clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
rk_priv->rockchip_clks);
free_pltfm:
sdhci_pltfm_free(pdev);
return err;
}
static void dwcmshc_remove(struct platform_device *pdev)
{
struct sdhci_host *host = platform_get_drvdata(pdev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
struct rk35xx_priv *rk_priv = priv->priv;
sdhci_remove_host(host, 0);
clk_disable_unprepare(pltfm_host->clk);
clk_disable_unprepare(priv->bus_clk);
if (rk_priv)
clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
rk_priv->rockchip_clks);
sdhci_pltfm_free(pdev);
}
#ifdef CONFIG_PM_SLEEP
static int dwcmshc_suspend(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
struct rk35xx_priv *rk_priv = priv->priv;
int ret;
pm_runtime_resume(dev);
ret = sdhci_suspend_host(host);
if (ret)
return ret;
clk_disable_unprepare(pltfm_host->clk);
if (!IS_ERR(priv->bus_clk))
clk_disable_unprepare(priv->bus_clk);
if (rk_priv)
clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
rk_priv->rockchip_clks);
return ret;
}
static int dwcmshc_resume(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
struct rk35xx_priv *rk_priv = priv->priv;
int ret;
ret = clk_prepare_enable(pltfm_host->clk);
if (ret)
return ret;
if (!IS_ERR(priv->bus_clk)) {
ret = clk_prepare_enable(priv->bus_clk);
if (ret)
goto disable_clk;
}
if (rk_priv) {
ret = clk_bulk_prepare_enable(RK35xx_MAX_CLKS,
rk_priv->rockchip_clks);
if (ret)
goto disable_bus_clk;
}
ret = sdhci_resume_host(host);
if (ret)
goto disable_rockchip_clks;
return 0;
disable_rockchip_clks:
if (rk_priv)
clk_bulk_disable_unprepare(RK35xx_MAX_CLKS,
rk_priv->rockchip_clks);
disable_bus_clk:
if (!IS_ERR(priv->bus_clk))
clk_disable_unprepare(priv->bus_clk);
disable_clk:
clk_disable_unprepare(pltfm_host->clk);
return ret;
}
#endif
#ifdef CONFIG_PM
static void dwcmshc_enable_card_clk(struct sdhci_host *host)
{
u16 ctrl;
ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
if ((ctrl & SDHCI_CLOCK_INT_EN) && !(ctrl & SDHCI_CLOCK_CARD_EN)) {
ctrl |= SDHCI_CLOCK_CARD_EN;
sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
}
}
static void dwcmshc_disable_card_clk(struct sdhci_host *host)
{
u16 ctrl;
ctrl = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
if (ctrl & SDHCI_CLOCK_CARD_EN) {
ctrl &= ~SDHCI_CLOCK_CARD_EN;
sdhci_writew(host, ctrl, SDHCI_CLOCK_CONTROL);
}
}
static int dwcmshc_runtime_suspend(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
dwcmshc_disable_card_clk(host);
return 0;
}
static int dwcmshc_runtime_resume(struct device *dev)
{
struct sdhci_host *host = dev_get_drvdata(dev);
dwcmshc_enable_card_clk(host);
return 0;
}
#endif
static const struct dev_pm_ops dwcmshc_pmops = {
SET_SYSTEM_SLEEP_PM_OPS(dwcmshc_suspend, dwcmshc_resume)
SET_RUNTIME_PM_OPS(dwcmshc_runtime_suspend,
dwcmshc_runtime_resume, NULL)
};
static struct platform_driver sdhci_dwcmshc_driver = {
.driver = {
.name = "sdhci-dwcmshc",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
.of_match_table = sdhci_dwcmshc_dt_ids,
.acpi_match_table = ACPI_PTR(sdhci_dwcmshc_acpi_ids),
.pm = &dwcmshc_pmops,
},
.probe = dwcmshc_probe,
.remove_new = dwcmshc_remove,
};
module_platform_driver(sdhci_dwcmshc_driver);
MODULE_DESCRIPTION("SDHCI platform driver for Synopsys DWC MSHC");
MODULE_AUTHOR("Jisheng Zhang <jszhang@kernel.org>");
MODULE_LICENSE("GPL v2");