mmci_stm32_sdmmc.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) STMicroelectronics 2018 - All Rights Reserved
* Author: Ludovic.barre@st.com for STMicroelectronics.
*/
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/iopoll.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/of_address.h>
#include <linux/reset.h>
#include <linux/scatterlist.h>
#include "mmci.h"
#define SDMMC_LLI_BUF_LEN PAGE_SIZE
#define SDMMC_IDMA_BURST BIT(MMCI_STM32_IDMABNDT_SHIFT)
#define DLYB_CR 0x0
#define DLYB_CR_DEN BIT(0)
#define DLYB_CR_SEN BIT(1)
#define DLYB_CFGR 0x4
#define DLYB_CFGR_SEL_MASK GENMASK(3, 0)
#define DLYB_CFGR_UNIT_MASK GENMASK(14, 8)
#define DLYB_CFGR_LNG_MASK GENMASK(27, 16)
#define DLYB_CFGR_LNGF BIT(31)
#define DLYB_NB_DELAY 11
#define DLYB_CFGR_SEL_MAX (DLYB_NB_DELAY + 1)
#define DLYB_CFGR_UNIT_MAX 127
#define DLYB_LNG_TIMEOUT_US 1000
#define SDMMC_VSWEND_TIMEOUT_US 10000
struct sdmmc_lli_desc {
u32 idmalar;
u32 idmabase;
u32 idmasize;
};
struct sdmmc_idma {
dma_addr_t sg_dma;
void *sg_cpu;
};
struct sdmmc_dlyb {
void __iomem *base;
u32 unit;
u32 max;
};
static int sdmmc_idma_validate_data(struct mmci_host *host,
struct mmc_data *data)
{
struct scatterlist *sg;
int i;
/*
* idma has constraints on idmabase & idmasize for each element
* excepted the last element which has no constraint on idmasize
*/
for_each_sg(data->sg, sg, data->sg_len - 1, i) {
if (!IS_ALIGNED(data->sg->offset, sizeof(u32)) ||
!IS_ALIGNED(data->sg->length, SDMMC_IDMA_BURST)) {
dev_err(mmc_dev(host->mmc),
"unaligned scatterlist: ofst:%x length:%d\n",
data->sg->offset, data->sg->length);
return -EINVAL;
}
}
if (!IS_ALIGNED(data->sg->offset, sizeof(u32))) {
dev_err(mmc_dev(host->mmc),
"unaligned last scatterlist: ofst:%x length:%d\n",
data->sg->offset, data->sg->length);
return -EINVAL;
}
return 0;
}
static int _sdmmc_idma_prep_data(struct mmci_host *host,
struct mmc_data *data)
{
int n_elem;
n_elem = dma_map_sg(mmc_dev(host->mmc),
data->sg,
data->sg_len,
mmc_get_dma_dir(data));
if (!n_elem) {
dev_err(mmc_dev(host->mmc), "dma_map_sg failed\n");
return -EINVAL;
}
return 0;
}
static int sdmmc_idma_prep_data(struct mmci_host *host,
struct mmc_data *data, bool next)
{
/* Check if job is already prepared. */
if (!next && data->host_cookie == host->next_cookie)
return 0;
return _sdmmc_idma_prep_data(host, data);
}
static void sdmmc_idma_unprep_data(struct mmci_host *host,
struct mmc_data *data, int err)
{
dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
mmc_get_dma_dir(data));
}
static int sdmmc_idma_setup(struct mmci_host *host)
{
struct sdmmc_idma *idma;
struct device *dev = mmc_dev(host->mmc);
idma = devm_kzalloc(dev, sizeof(*idma), GFP_KERNEL);
if (!idma)
return -ENOMEM;
host->dma_priv = idma;
if (host->variant->dma_lli) {
idma->sg_cpu = dmam_alloc_coherent(dev, SDMMC_LLI_BUF_LEN,
&idma->sg_dma, GFP_KERNEL);
if (!idma->sg_cpu) {
dev_err(dev, "Failed to alloc IDMA descriptor\n");
return -ENOMEM;
}
host->mmc->max_segs = SDMMC_LLI_BUF_LEN /
sizeof(struct sdmmc_lli_desc);
host->mmc->max_seg_size = host->variant->stm32_idmabsize_mask;
} else {
host->mmc->max_segs = 1;
host->mmc->max_seg_size = host->mmc->max_req_size;
}
return dma_set_max_seg_size(dev, host->mmc->max_seg_size);
}
static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl)
{
struct sdmmc_idma *idma = host->dma_priv;
struct sdmmc_lli_desc *desc = (struct sdmmc_lli_desc *)idma->sg_cpu;
struct mmc_data *data = host->data;
struct scatterlist *sg;
int i;
if (!host->variant->dma_lli || data->sg_len == 1) {
writel_relaxed(sg_dma_address(data->sg),
host->base + MMCI_STM32_IDMABASE0R);
writel_relaxed(MMCI_STM32_IDMAEN,
host->base + MMCI_STM32_IDMACTRLR);
return 0;
}
for_each_sg(data->sg, sg, data->sg_len, i) {
desc[i].idmalar = (i + 1) * sizeof(struct sdmmc_lli_desc);
desc[i].idmalar |= MMCI_STM32_ULA | MMCI_STM32_ULS
| MMCI_STM32_ABR;
desc[i].idmabase = sg_dma_address(sg);
desc[i].idmasize = sg_dma_len(sg);
}
/* notice the end of link list */
desc[data->sg_len - 1].idmalar &= ~MMCI_STM32_ULA;
dma_wmb();
writel_relaxed(idma->sg_dma, host->base + MMCI_STM32_IDMABAR);
writel_relaxed(desc[0].idmalar, host->base + MMCI_STM32_IDMALAR);
writel_relaxed(desc[0].idmabase, host->base + MMCI_STM32_IDMABASE0R);
writel_relaxed(desc[0].idmasize, host->base + MMCI_STM32_IDMABSIZER);
writel_relaxed(MMCI_STM32_IDMAEN | MMCI_STM32_IDMALLIEN,
host->base + MMCI_STM32_IDMACTRLR);
return 0;
}
static void sdmmc_idma_finalize(struct mmci_host *host, struct mmc_data *data)
{
writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR);
if (!data->host_cookie)
sdmmc_idma_unprep_data(host, data, 0);
}
static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired)
{
unsigned int clk = 0, ddr = 0;
if (host->mmc->ios.timing == MMC_TIMING_MMC_DDR52 ||
host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
ddr = MCI_STM32_CLK_DDR;
/*
* cclk = mclk / (2 * clkdiv)
* clkdiv 0 => bypass
* in ddr mode bypass is not possible
*/
if (desired) {
if (desired >= host->mclk && !ddr) {
host->cclk = host->mclk;
} else {
clk = DIV_ROUND_UP(host->mclk, 2 * desired);
if (clk > MCI_STM32_CLK_CLKDIV_MSK)
clk = MCI_STM32_CLK_CLKDIV_MSK;
host->cclk = host->mclk / (2 * clk);
}
} else {
/*
* while power-on phase the clock can't be define to 0,
* Only power-off and power-cyc deactivate the clock.
* if desired clock is 0, set max divider
*/
clk = MCI_STM32_CLK_CLKDIV_MSK;
host->cclk = host->mclk / (2 * clk);
}
/* Set actual clock for debug */
if (host->mmc->ios.power_mode == MMC_POWER_ON)
host->mmc->actual_clock = host->cclk;
else
host->mmc->actual_clock = 0;
if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
clk |= MCI_STM32_CLK_WIDEBUS_4;
if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
clk |= MCI_STM32_CLK_WIDEBUS_8;
clk |= MCI_STM32_CLK_HWFCEN;
clk |= host->clk_reg_add;
clk |= ddr;
/*
* SDMMC_FBCK is selected when an external Delay Block is needed
* with SDR104.
*/
if (host->mmc->ios.timing >= MMC_TIMING_UHS_SDR50) {
clk |= MCI_STM32_CLK_BUSSPEED;
if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104) {
clk &= ~MCI_STM32_CLK_SEL_MSK;
clk |= MCI_STM32_CLK_SELFBCK;
}
}
mmci_write_clkreg(host, clk);
}
static void sdmmc_dlyb_input_ck(struct sdmmc_dlyb *dlyb)
{
if (!dlyb || !dlyb->base)
return;
/* Output clock = Input clock */
writel_relaxed(0, dlyb->base + DLYB_CR);
}
static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
{
struct mmc_ios ios = host->mmc->ios;
struct sdmmc_dlyb *dlyb = host->variant_priv;
/* adds OF options */
pwr = host->pwr_reg_add;
sdmmc_dlyb_input_ck(dlyb);
if (ios.power_mode == MMC_POWER_OFF) {
/* Only a reset could power-off sdmmc */
reset_control_assert(host->rst);
udelay(2);
reset_control_deassert(host->rst);
/*
* Set the SDMMC in Power-cycle state.
* This will make that the SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK
* are driven low, to prevent the Card from being supplied
* through the signal lines.
*/
mmci_write_pwrreg(host, MCI_STM32_PWR_CYC | pwr);
} else if (ios.power_mode == MMC_POWER_ON) {
/*
* After power-off (reset): the irq mask defined in probe
* functionis lost
* ault irq mask (probe) must be activated
*/
writel(MCI_IRQENABLE | host->variant->start_err,
host->base + MMCIMASK0);
/* preserves voltage switch bits */
pwr |= host->pwr_reg & (MCI_STM32_VSWITCHEN |
MCI_STM32_VSWITCH);
/*
* After a power-cycle state, we must set the SDMMC in
* Power-off. The SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK are
* driven high. Then we can set the SDMMC to Power-on state
*/
mmci_write_pwrreg(host, MCI_PWR_OFF | pwr);
mdelay(1);
mmci_write_pwrreg(host, MCI_PWR_ON | pwr);
}
}
static u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
{
u32 datactrl;
datactrl = mmci_dctrl_blksz(host);
if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
host->data->blocks == 1)
datactrl |= MCI_DPSM_STM32_MODE_SDIO;
else if (host->data->stop && !host->mrq->sbc)
datactrl |= MCI_DPSM_STM32_MODE_BLOCK_STOP;
else
datactrl |= MCI_DPSM_STM32_MODE_BLOCK;
return datactrl;
}
static bool sdmmc_busy_complete(struct mmci_host *host, u32 status, u32 err_msk)
{
void __iomem *base = host->base;
u32 busy_d0, busy_d0end, mask, sdmmc_status;
mask = readl_relaxed(base + MMCIMASK0);
sdmmc_status = readl_relaxed(base + MMCISTATUS);
busy_d0end = sdmmc_status & MCI_STM32_BUSYD0END;
busy_d0 = sdmmc_status & MCI_STM32_BUSYD0;
/* complete if there is an error or busy_d0end */
if ((status & err_msk) || busy_d0end)
goto complete;
/*
* On response the busy signaling is reflected in the BUSYD0 flag.
* if busy_d0 is in-progress we must activate busyd0end interrupt
* to wait this completion. Else this request has no busy step.
*/
if (busy_d0) {
if (!host->busy_status) {
writel_relaxed(mask | host->variant->busy_detect_mask,
base + MMCIMASK0);
host->busy_status = status &
(MCI_CMDSENT | MCI_CMDRESPEND);
}
return false;
}
complete:
if (host->busy_status) {
writel_relaxed(mask & ~host->variant->busy_detect_mask,
base + MMCIMASK0);
host->busy_status = 0;
}
writel_relaxed(host->variant->busy_detect_mask, base + MMCICLEAR);
return true;
}
static void sdmmc_dlyb_set_cfgr(struct sdmmc_dlyb *dlyb,
int unit, int phase, bool sampler)
{
u32 cfgr;
writel_relaxed(DLYB_CR_SEN | DLYB_CR_DEN, dlyb->base + DLYB_CR);
cfgr = FIELD_PREP(DLYB_CFGR_UNIT_MASK, unit) |
FIELD_PREP(DLYB_CFGR_SEL_MASK, phase);
writel_relaxed(cfgr, dlyb->base + DLYB_CFGR);
if (!sampler)
writel_relaxed(DLYB_CR_DEN, dlyb->base + DLYB_CR);
}
static int sdmmc_dlyb_lng_tuning(struct mmci_host *host)
{
struct sdmmc_dlyb *dlyb = host->variant_priv;
u32 cfgr;
int i, lng, ret;
for (i = 0; i <= DLYB_CFGR_UNIT_MAX; i++) {
sdmmc_dlyb_set_cfgr(dlyb, i, DLYB_CFGR_SEL_MAX, true);
ret = readl_relaxed_poll_timeout(dlyb->base + DLYB_CFGR, cfgr,
(cfgr & DLYB_CFGR_LNGF),
1, DLYB_LNG_TIMEOUT_US);
if (ret) {
dev_warn(mmc_dev(host->mmc),
"delay line cfg timeout unit:%d cfgr:%d\n",
i, cfgr);
continue;
}
lng = FIELD_GET(DLYB_CFGR_LNG_MASK, cfgr);
if (lng < BIT(DLYB_NB_DELAY) && lng > 0)
break;
}
if (i > DLYB_CFGR_UNIT_MAX)
return -EINVAL;
dlyb->unit = i;
dlyb->max = __fls(lng);
return 0;
}
static int sdmmc_dlyb_phase_tuning(struct mmci_host *host, u32 opcode)
{
struct sdmmc_dlyb *dlyb = host->variant_priv;
int cur_len = 0, max_len = 0, end_of_len = 0;
int phase;
for (phase = 0; phase <= dlyb->max; phase++) {
sdmmc_dlyb_set_cfgr(dlyb, dlyb->unit, phase, false);
if (mmc_send_tuning(host->mmc, opcode, NULL)) {
cur_len = 0;
} else {
cur_len++;
if (cur_len > max_len) {
max_len = cur_len;
end_of_len = phase;
}
}
}
if (!max_len) {
dev_err(mmc_dev(host->mmc), "no tuning point found\n");
return -EINVAL;
}
phase = end_of_len - max_len / 2;
sdmmc_dlyb_set_cfgr(dlyb, dlyb->unit, phase, false);
dev_dbg(mmc_dev(host->mmc), "unit:%d max_dly:%d phase:%d\n",
dlyb->unit, dlyb->max, phase);
return 0;
}
static int sdmmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
{
struct mmci_host *host = mmc_priv(mmc);
struct sdmmc_dlyb *dlyb = host->variant_priv;
if (!dlyb || !dlyb->base)
return -EINVAL;
if (sdmmc_dlyb_lng_tuning(host))
return -EINVAL;
return sdmmc_dlyb_phase_tuning(host, opcode);
}
static void sdmmc_pre_sig_volt_vswitch(struct mmci_host *host)
{
/* clear the voltage switch completion flag */
writel_relaxed(MCI_STM32_VSWENDC, host->base + MMCICLEAR);
/* enable Voltage switch procedure */
mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCHEN);
}
static int sdmmc_post_sig_volt_switch(struct mmci_host *host,
struct mmc_ios *ios)
{
unsigned long flags;
u32 status;
int ret = 0;
if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
spin_lock_irqsave(&host->lock, flags);
mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCH);
spin_unlock_irqrestore(&host->lock, flags);
/* wait voltage switch completion while 10ms */
ret = readl_relaxed_poll_timeout(host->base + MMCISTATUS,
status,
(status & MCI_STM32_VSWEND),
10, SDMMC_VSWEND_TIMEOUT_US);
writel_relaxed(MCI_STM32_VSWENDC | MCI_STM32_CKSTOPC,
host->base + MMCICLEAR);
mmci_write_pwrreg(host, host->pwr_reg &
~(MCI_STM32_VSWITCHEN | MCI_STM32_VSWITCH));
}
return ret;
}
static struct mmci_host_ops sdmmc_variant_ops = {
.validate_data = sdmmc_idma_validate_data,
.prep_data = sdmmc_idma_prep_data,
.unprep_data = sdmmc_idma_unprep_data,
.get_datactrl_cfg = sdmmc_get_dctrl_cfg,
.dma_setup = sdmmc_idma_setup,
.dma_start = sdmmc_idma_start,
.dma_finalize = sdmmc_idma_finalize,
.set_clkreg = mmci_sdmmc_set_clkreg,
.set_pwrreg = mmci_sdmmc_set_pwrreg,
.busy_complete = sdmmc_busy_complete,
.pre_sig_volt_switch = sdmmc_pre_sig_volt_vswitch,
.post_sig_volt_switch = sdmmc_post_sig_volt_switch,
};
void sdmmc_variant_init(struct mmci_host *host)
{
struct device_node *np = host->mmc->parent->of_node;
void __iomem *base_dlyb;
struct sdmmc_dlyb *dlyb;
host->ops = &sdmmc_variant_ops;
host->pwr_reg = readl_relaxed(host->base + MMCIPOWER);
base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL);
if (IS_ERR(base_dlyb))
return;
dlyb = devm_kzalloc(mmc_dev(host->mmc), sizeof(*dlyb), GFP_KERNEL);
if (!dlyb)
return;
dlyb->base = base_dlyb;
host->variant_priv = dlyb;
host->mmc_ops->execute_tuning = sdmmc_execute_tuning;
}