linux-sg2042/drivers/mmc/host/mmci_stm32_sdmmc.c

283 lines
7.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) STMicroelectronics 2018 - All Rights Reserved
* Author: Ludovic.barre@st.com for STMicroelectronics.
*/
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.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)
struct sdmmc_lli_desc {
u32 idmalar;
u32 idmabase;
u32 idmasize;
};
struct sdmmc_priv {
dma_addr_t sg_dma;
void *sg_cpu;
};
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(sg_dma_address(data->sg), sizeof(u32)) ||
!IS_ALIGNED(sg_dma_len(data->sg), 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(sg_dma_address(data->sg), 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_priv *idma;
idma = devm_kzalloc(mmc_dev(host->mmc), sizeof(*idma), GFP_KERNEL);
if (!idma)
return -ENOMEM;
host->dma_priv = idma;
if (host->variant->dma_lli) {
idma->sg_cpu = dmam_alloc_coherent(mmc_dev(host->mmc),
SDMMC_LLI_BUF_LEN,
&idma->sg_dma, GFP_KERNEL);
if (!idma->sg_cpu) {
dev_err(mmc_dev(host->mmc),
"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 0;
}
static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl)
{
struct sdmmc_priv *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);
}
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 mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
{
struct mmc_ios ios = host->mmc->ios;
pwr = host->pwr_reg_add;
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);
/*
* 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 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,
.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,
};
void sdmmc_variant_init(struct mmci_host *host)
{
host->ops = &sdmmc_variant_ops;
}