sdhci-sirf.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SDHCI support for SiRF primaII and marco SoCs
*
* Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/mmc/host.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/mmc/slot-gpio.h>
#include "sdhci-pltfm.h"
#define SDHCI_CLK_DELAY_SETTING 0x4C
#define SDHCI_SIRF_8BITBUS BIT(3)
#define SIRF_TUNING_COUNT 16384
static void sdhci_sirf_set_bus_width(struct sdhci_host *host, int width)
{
u8 ctrl;
ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
ctrl &= ~(SDHCI_CTRL_4BITBUS | SDHCI_SIRF_8BITBUS);
/*
* CSR atlas7 and prima2 SD host version is not 3.0
* 8bit-width enable bit of CSR SD hosts is 3,
* while stardard hosts use bit 5
*/
if (width == MMC_BUS_WIDTH_8)
ctrl |= SDHCI_SIRF_8BITBUS;
else if (width == MMC_BUS_WIDTH_4)
ctrl |= SDHCI_CTRL_4BITBUS;
sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
}
static u32 sdhci_sirf_readl_le(struct sdhci_host *host, int reg)
{
u32 val = readl(host->ioaddr + reg);
if (unlikely((reg == SDHCI_CAPABILITIES_1) &&
(host->mmc->caps & MMC_CAP_UHS_SDR50))) {
/* fake CAP_1 register */
val = SDHCI_SUPPORT_DDR50 |
SDHCI_SUPPORT_SDR50 | SDHCI_USE_SDR50_TUNING;
}
if (unlikely(reg == SDHCI_SLOT_INT_STATUS)) {
u32 prss = val;
/* fake chips as V3.0 host conreoller */
prss &= ~(0xFF << 16);
val = prss | (SDHCI_SPEC_300 << 16);
}
return val;
}
static u16 sdhci_sirf_readw_le(struct sdhci_host *host, int reg)
{
u16 ret = 0;
ret = readw(host->ioaddr + reg);
if (unlikely(reg == SDHCI_HOST_VERSION)) {
ret = readw(host->ioaddr + SDHCI_HOST_VERSION);
ret |= SDHCI_SPEC_300;
}
return ret;
}
static int sdhci_sirf_execute_tuning(struct sdhci_host *host, u32 opcode)
{
int tuning_seq_cnt = 3;
int phase;
u8 tuned_phase_cnt = 0;
int rc = 0, longest_range = 0;
int start = -1, end = 0, tuning_value = -1, range = 0;
u16 clock_setting;
struct mmc_host *mmc = host->mmc;
clock_setting = sdhci_readw(host, SDHCI_CLK_DELAY_SETTING);
clock_setting &= ~0x3fff;
retry:
phase = 0;
tuned_phase_cnt = 0;
do {
sdhci_writel(host,
clock_setting | phase,
SDHCI_CLK_DELAY_SETTING);
if (!mmc_send_tuning(mmc, opcode, NULL)) {
/* Tuning is successful at this tuning point */
tuned_phase_cnt++;
dev_dbg(mmc_dev(mmc), "%s: Found good phase = %d\n",
mmc_hostname(mmc), phase);
if (start == -1)
start = phase;
end = phase;
range++;
if (phase == (SIRF_TUNING_COUNT - 1)
&& range > longest_range)
tuning_value = (start + end) / 2;
} else {
dev_dbg(mmc_dev(mmc), "%s: Found bad phase = %d\n",
mmc_hostname(mmc), phase);
if (range > longest_range) {
tuning_value = (start + end) / 2;
longest_range = range;
}
start = -1;
end = range = 0;
}
} while (++phase < SIRF_TUNING_COUNT);
if (tuned_phase_cnt && tuning_value > 0) {
/*
* Finally set the selected phase in delay
* line hw block.
*/
phase = tuning_value;
sdhci_writel(host,
clock_setting | phase,
SDHCI_CLK_DELAY_SETTING);
dev_dbg(mmc_dev(mmc), "%s: Setting the tuning phase to %d\n",
mmc_hostname(mmc), phase);
} else {
if (--tuning_seq_cnt)
goto retry;
/* Tuning failed */
dev_dbg(mmc_dev(mmc), "%s: No tuning point found\n",
mmc_hostname(mmc));
rc = -EIO;
}
return rc;
}
static const struct sdhci_ops sdhci_sirf_ops = {
.read_l = sdhci_sirf_readl_le,
.read_w = sdhci_sirf_readw_le,
.platform_execute_tuning = sdhci_sirf_execute_tuning,
.set_clock = sdhci_set_clock,
.get_max_clock = sdhci_pltfm_clk_get_max_clock,
.set_bus_width = sdhci_sirf_set_bus_width,
.reset = sdhci_reset,
.set_uhs_signaling = sdhci_set_uhs_signaling,
};
static const struct sdhci_pltfm_data sdhci_sirf_pdata = {
.ops = &sdhci_sirf_ops,
.quirks = SDHCI_QUIRK_BROKEN_TIMEOUT_VAL |
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK |
SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
SDHCI_QUIRK_RESET_CMD_DATA_ON_IOS,
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
};
static int sdhci_sirf_probe(struct platform_device *pdev)
{
struct sdhci_host *host;
struct sdhci_pltfm_host *pltfm_host;
struct clk *clk;
int ret;
clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "unable to get clock");
return PTR_ERR(clk);
}
host = sdhci_pltfm_init(pdev, &sdhci_sirf_pdata, 0);
if (IS_ERR(host))
return PTR_ERR(host);
pltfm_host = sdhci_priv(host);
pltfm_host->clk = clk;
sdhci_get_of_property(pdev);
ret = clk_prepare_enable(pltfm_host->clk);
if (ret)
goto err_clk_prepare;
ret = sdhci_add_host(host);
if (ret)
goto err_sdhci_add;
/*
* We must request the IRQ after sdhci_add_host(), as the tasklet only
* gets setup in sdhci_add_host() and we oops.
*/
ret = mmc_gpiod_request_cd(host->mmc, "cd", 0, false, 0);
if (ret == -EPROBE_DEFER)
goto err_request_cd;
if (!ret)
mmc_gpiod_request_cd_irq(host->mmc);
return 0;
err_request_cd:
sdhci_remove_host(host, 0);
err_sdhci_add:
clk_disable_unprepare(pltfm_host->clk);
err_clk_prepare:
sdhci_pltfm_free(pdev);
return ret;
}
static const struct of_device_id sdhci_sirf_of_match[] = {
{ .compatible = "sirf,prima2-sdhc" },
{ }
};
MODULE_DEVICE_TABLE(of, sdhci_sirf_of_match);
static struct platform_driver sdhci_sirf_driver = {
.driver = {
.name = "sdhci-sirf",
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
.of_match_table = sdhci_sirf_of_match,
.pm = &sdhci_pltfm_pmops,
},
.probe = sdhci_sirf_probe,
.remove = sdhci_pltfm_unregister,
};
module_platform_driver(sdhci_sirf_driver);
MODULE_DESCRIPTION("SDHCI driver for SiRFprimaII/SiRFmarco");
MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_LICENSE("GPL v2");