Re: [PATCH v1 3/3] mmc: Add driver for LiteX's LiteSDCard interface
From: Stafford Horne <shorne@gmail.com>
Date: 2021-12-04 07:29:40
Also in:
linux-mmc, lkml
On Fri, Dec 03, 2021 at 06:41:55PM -0500, Gabriel Somlo wrote:
quoted hunk ↗ jump to hunk
LiteX (https://github.com/enjoy-digital/litex) is a SoC framework that targets FPGAs. LiteSDCard is a small footprint, configurable SDCard core commonly used in LiteX designs. The driver was first written in May 2020 and has been maintained cooperatively by the LiteX community. Thanks to all contributors! Co-developed-by: Kamil Rakoczy <redacted> Signed-off-by: Kamil Rakoczy <redacted> Co-developed-by: Maciej Dudek <redacted> Signed-off-by: Maciej Dudek <redacted> Co-developed-by: Paul Mackerras <redacted> Signed-off-by: Paul Mackerras <redacted> Signed-off-by: Gabriel Somlo <gsomlo@gmail.com> Cc: Mateusz Holenko <mholenko@antmicro.com> Cc: Karol Gugala <kgugala@antmicro.com> Cc: Joel Stanley <joel@jms.id.au> Cc: Stafford Horne <shorne@gmail.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Abdurachmanov <redacted> Cc: Florent Kermarrec <redacted> --- drivers/mmc/host/Kconfig | 6 + drivers/mmc/host/Makefile | 1 + drivers/mmc/host/litex_mmc.c | 677 +++++++++++++++++++++++++++++++++++ 3 files changed, 684 insertions(+) create mode 100644 drivers/mmc/host/litex_mmc.cdiff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig index 5af8494c31b5..84c64e72195d 100644 --- a/drivers/mmc/host/Kconfig +++ b/drivers/mmc/host/Kconfig@@ -1093,3 +1093,9 @@ config MMC_OWL config MMC_SDHCI_EXTERNAL_DMA bool + +config MMC_LITEX + tristate "Support for the MMC Controller in LiteX SOCs" + depends on OF && LITEX
Shall we allow compile test here like this?
depends on OF || COMPILE_TEST
depends on LITEX || COMPILE_TEST
This is what was added for liteuart [0].
[0] https://lore.kernel.org/all/CAHp75Ve9MB4MW9KDPoNhnPa8TCabmMgLbt6H7qrGgwmA8CpdNg@mail.gmail.com/T/#mad93ad951031f8e975a1c632873f516598aec272 (local)
quoted hunk ↗ jump to hunk
+ help + Generic MCC driver for LiteXdiff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile index ea36d379bd3c..4e4ceb32c4b4 100644 --- a/drivers/mmc/host/Makefile +++ b/drivers/mmc/host/Makefile@@ -101,6 +101,7 @@ obj-$(CONFIG_MMC_CQHCI) += cqhci.o cqhci-y += cqhci-core.o cqhci-$(CONFIG_MMC_CRYPTO) += cqhci-crypto.o obj-$(CONFIG_MMC_HSQ) += mmc_hsq.o +obj-$(CONFIG_MMC_LITEX) += litex_mmc.o ifeq ($(CONFIG_CB710_DEBUG),y) CFLAGS-cb710-mmc += -DDEBUGdiff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c new file mode 100644 index 000000000000..3877379757cd --- /dev/null +++ b/drivers/mmc/host/litex_mmc.c@@ -0,0 +1,677 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * LiteX LiteSDCard driver + * + * Copyright (C) 2019-2020 Antmicro <www.antmicro.com> + * + */ + +#include <linux/module.h> +#include <linux/litex.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/mmc/sd.h> +#include <linux/mmc/mmc.h> +#include <linux/mmc/host.h> +#include <linux/mmc/slot-gpio.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> + +#define LITEX_PHY_CARDDETECT 0x00 +#define LITEX_PHY_CLOCKERDIV 0x04 +#define LITEX_PHY_INITIALIZE 0x08 +#define LITEX_PHY_WRITESTATUS 0x0C +#define LITEX_CORE_CMDARG 0x00 +#define LITEX_CORE_CMDCMD 0x04 +#define LITEX_CORE_CMDSND 0x08 +#define LITEX_CORE_CMDRSP 0x0C +#define LITEX_CORE_CMDEVT 0x1C +#define LITEX_CORE_DATAEVT 0x20 +#define LITEX_CORE_BLKLEN 0x24 +#define LITEX_CORE_BLKCNT 0x28 +#define LITEX_BLK2MEM_BASE 0x00 +#define LITEX_BLK2MEM_LEN 0x08 +#define LITEX_BLK2MEM_ENA 0x0C +#define LITEX_BLK2MEM_DONE 0x10 +#define LITEX_BLK2MEM_LOOP 0x14 +#define LITEX_MEM2BLK_BASE 0x00 +#define LITEX_MEM2BLK_LEN 0x08 +#define LITEX_MEM2BLK_ENA 0x0C +#define LITEX_MEM2BLK_DONE 0x10 +#define LITEX_MEM2BLK_LOOP 0x14 +#define LITEX_MEM2BLK 0x18 +#define LITEX_IRQ_STATUS 0x00 +#define LITEX_IRQ_PENDING 0x04 +#define LITEX_IRQ_ENABLE 0x08 + +#define SDCARD_CTRL_DATA_TRANSFER_NONE 0 +#define SDCARD_CTRL_DATA_TRANSFER_READ 1 +#define SDCARD_CTRL_DATA_TRANSFER_WRITE 2 + +#define SDCARD_CTRL_RESPONSE_NONE 0 +#define SDCARD_CTRL_RESPONSE_SHORT 1 +#define SDCARD_CTRL_RESPONSE_LONG 2 +#define SDCARD_CTRL_RESPONSE_SHORT_BUSY 3 + +#define SD_OK 0 +#define SD_WRITEERROR 1 +#define SD_TIMEOUT 2 +#define SD_CRCERROR 3 +#define SD_ERR_OTHER 4 + +#define SDIRQ_CARD_DETECT 1 +#define SDIRQ_SD_TO_MEM_DONE 2 +#define SDIRQ_MEM_TO_SD_DONE 4 +#define SDIRQ_CMD_DONE 8 + +struct litex_mmc_host { + struct mmc_host *mmc; + struct platform_device *dev; + + void __iomem *sdphy; + void __iomem *sdcore; + void __iomem *sdreader; + void __iomem *sdwriter; + void __iomem *sdirq; + + u32 resp[4]; + u16 rca; + + void *buffer; + size_t buf_size; + dma_addr_t dma; + + unsigned int freq; + unsigned int clock; + bool is_bus_width_set; + bool app_cmd; + + int irq; + struct completion cmd_done; +}; + +static int +sdcard_wait_done(void __iomem *reg) +{ + u8 evt; + + for (;;) { + evt = litex_read8(reg); + if (evt & 0x1) + break; + udelay(5); + }
Should we replace this with something like read_poll_timeout?
if (read_poll_timeout(litex_read8, evt, (evt & 0x1),
5, 20000, false, reg)) {
pr_err ("read timeout ....");
return SD_TIMEOUT;
}
Otherwise we could be locked here forever.
+ if (evt == 0x1)
+ return SD_OK;
+ if (evt & 0x2)
+ return SD_WRITEERROR;
+ if (evt & 0x4)
+ return SD_TIMEOUT;
+ if (evt & 0x8)
+ return SD_CRCERROR;
+ pr_err("%s: unknown error evt=%x\n", __func__, evt);
+ return SD_ERR_OTHER;
+}
+
+static int
+send_cmd(struct litex_mmc_host *host,
+ u8 cmd, u32 arg, u8 response_len, u8 transfer)
+{
+ void __iomem *reg;
+ ulong n;
+ u8 i;
+ int status;
+
+ litex_write32(host->sdcore + LITEX_CORE_CMDARG, arg);
+ litex_write32(host->sdcore + LITEX_CORE_CMDCMD,
+ cmd << 8 | transfer << 5 | response_len);
+ litex_write8(host->sdcore + LITEX_CORE_CMDSND, 1);
+
+ /* Wait for an interrupt if we have an interrupt and either there is
+ * data to be transferred, or if the card can report busy via DAT0.
+ */
+ if (host->irq > 0 &&
+ (transfer != SDCARD_CTRL_DATA_TRANSFER_NONE ||
+ response_len == SDCARD_CTRL_RESPONSE_SHORT_BUSY)) {
+ reinit_completion(&host->cmd_done);
+ litex_write32(host->sdirq + LITEX_IRQ_ENABLE,
+ SDIRQ_CMD_DONE | SDIRQ_CARD_DETECT);
+ wait_for_completion(&host->cmd_done);
+ }
+
+ status = sdcard_wait_done(host->sdcore + LITEX_CORE_CMDEVT);
+
+ if (status != SD_OK) {
+ pr_err("Command (cmd %d) failed, status %d\n", cmd, status);
+ return status;
+ }
+
+ if (response_len != SDCARD_CTRL_RESPONSE_NONE) {
+ reg = host->sdcore + LITEX_CORE_CMDRSP;
+ for (i = 0; i < 4; i++) {
+ host->resp[i] = litex_read32(reg);
+ reg += sizeof(u32);
+ }
+ }
+
+ if (!host->app_cmd && cmd == SD_SEND_RELATIVE_ADDR)
+ host->rca = (host->resp[3] >> 16) & 0xffff;
+
+ host->app_cmd = (cmd == MMC_APP_CMD);
+
+ if (transfer == SDCARD_CTRL_DATA_TRANSFER_NONE)
+ return status; /* SD_OK from prior sdcard_wait_done(cmd_evt) */
+
+ status = sdcard_wait_done(host->sdcore + LITEX_CORE_DATAEVT);
+ if (status != SD_OK) {
+ pr_err("Data xfer (cmd %d) failed, status %d\n", cmd, status);
+ return status;
+ }
+
+ /* wait for completion of (read or write) DMA transfer */
+ reg = (transfer == SDCARD_CTRL_DATA_TRANSFER_READ) ?
+ host->sdreader + LITEX_BLK2MEM_DONE :
+ host->sdwriter + LITEX_MEM2BLK_DONE;
+ n = jiffies + (HZ << 1);
+ while ((litex_read8(reg) & 0x01) == 0)
+ if (time_after(jiffies, n)) {
+ pr_err("DMA timeout (cmd %d)\n", cmd);
+ return SD_TIMEOUT;
+ }We could use read_poll_timeout here too.
+ + return status; +} +
-Stafford