Add support for the LiteX SD-Card device, LiteSDCard.
LiteSDCard is a simple SD-Card interface available as part of the LiteX
environment, used with various RISC-V and other FPGA based SoCs.
New in v11:
- picked up r/b from Andy
drivers/mmc/host/litex_mmc.c:
- defensive coding of litex_mmc_interrupt() return logic
- remove `dev` member of `struct litex_mmc_host`, only used during probe
>New in v10:
>drivers/mmc/host/litex_mmc.c:
> - group `linux/mmc/*` includes by themselves
> - clean-up of `return` style (multiple locations throughout source)
> - create `mmc_free_host()` wrapper for use with
> `devm_add_action_or_reset()`
> - use GFP_KERNEL with `dmam_alloc_coherent()`
>
>>New in v9:
>>drivers/mmc/host/Kconfig:
>> - fix OF dependency
>>drivers/mmc/host/litex_mmc.c:
>> - remove `linux/of.h` include, no longer needed since dropping
>> `of_match_ptr()`
>> - add `linux/mod_devicetable.h` include
>> - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate
>> the need to call mmc_free_host() explicitly during either probe()
>> error path or during remove()
>>
>>>New in v8:
>>>commit blurbs:
>>> - cosmetic editing of descriptions
>>> - removed `Cc:` lines
>>>drivers/mmc/host/litex_mmc.c:
>>> - fix file header comment (for real, this time)
>>> - add explicit `bits.h` include
>>> - remove `of_match_ptr()` wrapper from around .of_match_table argument
>>> - fix devm ordering issues: use `devm_request_irq()`, which precludes
>>> the need to call `free_irq()` on `probe()` error path or from `remove()`
>>>
>>>>New in v7:
>>>>
>>>>drivers/mmc/host/Kconfig:
>>>> - added module name in LiteSDCard Kconfig entry
>>>>
>>>>drivers/mmc/host/litex_mmc.c:
>>>> - fixed comment formatting, ordering, and capitalization throughout
>>>> the entire file
>>>> - sorted header #include statements
>>>> - removed redundant parantheses in readx_poll_timeout() condition
>>>> - explicit handling of readx_poll_timeout() timeout scenarios
>>>> - dev_err() used in litex_mmc_sdcard_wait_done()
>>>> - use memcpy_fromio() to grab command response
>>>> - no need to apply 0xffff mask to a 32-bit value right-shifted by 16
>>>> (host->resp[3])
>>>> - use clamp() instead of min(max(...)...)
>>>> - reworked platform_get_irq_optional() error handling logic
>>>> - no need to explicitly zero host->irq, kzalloc() does that already
>>>> - added missing free_irq() in litex_mmc_probe() error path
>>>> - reordered calls inside litex_mmc_remove() (calling mmc_free_host()
>>>> before free_irq()
>>>>
>>>>>New in v6:
>>>>>
>>>>>drivers/mmc/host/litex_mmc.c:
>>>>> - fix handling of deferred probe vs. platform_get_irq_optional()
>>>>> - don't #ifdef dma_set_mask_and_coherent(), since it automatically
>>>>> does the right thing on both 32- and 64-bit DMA capable arches
>>>>> - remove MMC_CAP2_FULL_PWR_CYCLE, add MMC_CAP2_NO_MMC to list of
>>>>> hardcoded capabilities during litex_mmc_probe()
>>>>> - hardcode mmc->ocr_avail to the full 2.7-3.6V range allowed by the
>>>>> SDCard spec (the LiteSDCard device doesn't accept software
>>>>> configuration)
>>>>>
>>>>>>New in v5:
>>>>>>
>>>>>>MAINTAINERS:
>>>>>>
>>>>>> - picked up a/b Mateusz
>>>>>>
>>>>>>Doc/dt/bindings/mmc/litex,mmc.yaml:
>>>>>>
>>>>>> - picked up r/b Rob, Joel
>>>>>>
>>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>>
>>>>>> - shorten #define constant names (cosmetic, make them less unwieldy)
>>>>>> - picked up r/b Joel
>>>>>>
>>>>>>>New in v4:
>>>>>>>
>>>>>>>Doc/dt/bindings/mmc/litex,mmc.yaml:
>>>>>>>
>>>>>>> - fixed `dt_binding_check` errors uncovered by Rob's script
>>>>>>>
>>>>>>>drivers/mmc/host/litex_mmc.c:
>>>>>>>
>>>>>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports
>>>>>>> no holes in either 32- or 64-bit builds
>>>>>>> - litex_mmc_set_bus_width() now encapsulates check for
>>>>>>> host->is_bus_width_set
>>>>>>> - litex_mmc_request() - factor out dma data setup into separate
>>>>>>> helper function: litex_mmc_do_dma()
>>>>>>>
>>>>>>>>New in v3:
>>>>>>>>
>>>>>>>> MAINTAINERS:
>>>>>>>>
>>>>>>>> - picked up acked-by Joel
>>>>>>>> - added listing for liteeth driver
>>>>>>>> - added Joel as additional co-maintainer (thanks!)
>>>>>>>>
>>>>>>>> Doc/dt/bindings/mmc/litex,mmc.yaml:
>>>>>>>>
>>>>>>>> - picked up r/b Geert Uytterhoeven <[email protected]> in DT
>>>>>>>> bindings document (please let me know if that was premature, and
>>>>>>>> happy to take further review if needed :)
>>>>>>>> - add dedicated DT property for source clock frequency
>>>>>>>>
>>>>>>>> drivers/mmc/host/litex_mmc.c:
>>>>>>>>
>>>>>>>> - fixed function signature (no line split), and naming (litex_mmc_*)
>>>>>>>> - more informative MODULE_AUTHOR() entries
>>>>>>>> - also added matching "Copyright" entries in file header
>>>>>>>> - fixed description in Kconfig
>>>>>>>> - fixed DT documentation
>>>>>>>> - removed magic constants
>>>>>>>> - removed litex_map_status(), have sdcard_wait_done() return *real*
>>>>>>>> error codes directly instead.
>>>>>>>> - streamlined litex_mmc_reponse_len()
>>>>>>>> - call litex_mmc_set_bus_width() only once, and ensure it returns
>>>>>>>> correct error code(s)
>>>>>>>> - use readx_poll_timeout() -- more concise -- instead of
>>>>>>>> read_poll_timeout()
>>>>>>>> - use dev_err() in litex_mmc_send_cmd() (instead of pr_err())
>>>>>>>> - litex_mmc_setclk() will update host->clock before returning
>>>>>>>> - separate irq initialization into its own function,
>>>>>>>> litex_mmc_irq_init()
>>>>>>>> - document rationale for f_min, f_max
>>>>>>>> - use dmam_alloc_coherent(), which simplifies cleanup significantly
>>>>>>>> - large `if (data) { ... }` block in litex_mmc_request() left as-is,
>>>>>>>> there are too many variables shared with the rest of the parent
>>>>>>>> function body to easily separate (e.g., `len`, `transfer`, `direct`).
>>>>>>>> If this is indeed a blocker, I can take another shot at refactoring
>>>>>>>> it in a future revision!
>>>>>>>> - bump dma_set_mask_and_coherent() to 64-bits on suitable
>>>>>>>> architectures
>>>>>>>> - clock source picked up from dedicated DT clock reference property
>>>>>>>> - remove gpio card-detect logic (needs testing and a dt binding
>>>>>>>> example before being eligible for upstream inclusion)
>>>>>>>>
>>>>>>>>> New in v2:
>>>>>>>>> - reword info message in litex_set_clk()
>>>>>>>>> - streamline code in litex_map_status()
>>>>>>>>> - fix typos in Kconfig (thanks Randy Dunlap <[email protected]>)
>>>>>>>>> - improvements suggested by Stafford Horne <[email protected]>
>>>>>>>>> - allow COMPILE_TEST in Kconfig
>>>>>>>>> - use read_poll_timeout() when waiting for cmd/data/DMA
>>>>>>>>> xfer completion
>>>>>>>>> - include interrupt.h (thanks kernel test robot <[email protected]>)
Gabriel Somlo (3):
MAINTAINERS: co-maintain LiteX platform
dt-bindings: mmc: Add bindings for LiteSDCard
mmc: Add driver for LiteX's LiteSDCard interface
.../devicetree/bindings/mmc/litex,mmc.yaml | 72 ++
MAINTAINERS | 9 +-
drivers/mmc/host/Kconfig | 9 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/litex_mmc.c | 657 ++++++++++++++++++
5 files changed, 746 insertions(+), 2 deletions(-)
create mode 100644 Documentation/devicetree/bindings/mmc/litex,mmc.yaml
create mode 100644 drivers/mmc/host/litex_mmc.c
--
2.31.1
Add the litex_mmc (LiteSDCard) and LiteETH drivers to the list
of files maintained under LiteX.
Add Gabriel Somlo and Joel Stanley as maintainers; Joel authored
the LiteETH driver, and Gabriel is currently curating the LiteX
out-of-tree device drivers as they are tested and prepared for
upstream submission, having also co-authored a number of them.
Signed-off-by: Gabriel Somlo <[email protected]>
Acked-by: Joel Stanley <[email protected]>
Acked-by: Mateusz Holenko <[email protected]>
---
MAINTAINERS | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/MAINTAINERS b/MAINTAINERS
index dd36acc87ce6..88f105711b85 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -11012,12 +11012,17 @@ F: lib/list-test.c
LITEX PLATFORM
M: Karol Gugala <[email protected]>
M: Mateusz Holenko <[email protected]>
+M: Gabriel Somlo <[email protected]>
+M: Joel Stanley <[email protected]>
S: Maintained
F: Documentation/devicetree/bindings/*/litex,*.yaml
F: arch/openrisc/boot/dts/or1klitex.dts
-F: drivers/soc/litex/litex_soc_ctrl.c
-F: drivers/tty/serial/liteuart.c
F: include/linux/litex.h
+F: drivers/tty/serial/liteuart.c
+F: drivers/soc/litex/*
+F: drivers/net/ethernet/litex/*
+F: drivers/mmc/host/litex_mmc.c
+N: litex
LIVE PATCHING
M: Josh Poimboeuf <[email protected]>
--
2.31.1
LiteSDCard is a small footprint, configurable SDCard core for
FPGA based SoCs.
Signed-off-by: Gabriel Somlo <[email protected]>
Reviewed-by: Geert Uytterhoeven <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
---
.../devicetree/bindings/mmc/litex,mmc.yaml | 72 +++++++++++++++++++
1 file changed, 72 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mmc/litex,mmc.yaml
diff --git a/Documentation/devicetree/bindings/mmc/litex,mmc.yaml b/Documentation/devicetree/bindings/mmc/litex,mmc.yaml
new file mode 100644
index 000000000000..f57cf42b8db7
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/litex,mmc.yaml
@@ -0,0 +1,72 @@
+# SPDX-License-Identifier: GPL-2.0-or-later OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/litex,mmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: LiteX LiteSDCard device
+
+maintainers:
+ - Gabriel Somlo <[email protected]>
+
+description: |
+ LiteSDCard is a small footprint, configurable SDCard core for FPGA based
+ system on chips.
+
+ The hardware source is Open Source and can be found on at
+ https://github.com/enjoy-digital/litesdcard/.
+
+allOf:
+ - $ref: mmc-controller.yaml#
+
+properties:
+ compatible:
+ const: litex,mmc
+
+ reg:
+ items:
+ - description: PHY registers
+ - description: CORE registers
+ - description: DMA Reader buffer
+ - description: DMA Writer buffer
+ - description: IRQ registers
+ minItems: 4
+
+ reg-names:
+ items:
+ - const: phy
+ - const: core
+ - const: reader
+ - const: writer
+ - const: irq
+ minItems: 4
+
+ clocks:
+ maxItems: 1
+ description:
+ Handle to reference clock.
+
+ interrupts:
+ maxItems: 1
+
+required:
+ - compatible
+ - reg
+ - reg-names
+ - clocks
+
+additionalProperties: false
+
+examples:
+ - |
+ mmc: mmc@12005000 {
+ compatible = "litex,mmc";
+ reg = <0x12005000 0x100>,
+ <0x12003800 0x100>,
+ <0x12003000 0x100>,
+ <0x12004800 0x100>,
+ <0x12004000 0x100>;
+ reg-names = "phy", "core", "reader", "writer", "irq";
+ clocks = <&reference_clk>;
+ interrupts = <4>;
+ };
--
2.31.1
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 <[email protected]>
Signed-off-by: Kamil Rakoczy <[email protected]>
Co-developed-by: Maciej Dudek <[email protected]>
Signed-off-by: Maciej Dudek <[email protected]>
Co-developed-by: Paul Mackerras <[email protected]>
Signed-off-by: Paul Mackerras <[email protected]>
Signed-off-by: Gabriel Somlo <[email protected]>
Reviewed-by: Joel Stanley <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
---
New in v11:
- picked up r/b from Andy
drivers/mmc/host/litex_mmc.c:
- defensive coding of litex_mmc_interrupt() return logic
- remove `dev` member of `struct litex_mmc_host`, only used during probe
>New in v10:
>drivers/mmc/host/litex_mmc.c:
> - group `linux/mmc/*` includes by themselves
> - clean-up of `return` style (multiple locations throughout source)
> - create `mmc_free_host()` wrapper for use with
> `devm_add_action_or_reset()`
> - use GFP_KERNEL with `dmam_alloc_coherent()`
>
>>New in v9:
>>drivers/mmc/host/Kconfig:
>> - fix OF dependency
>>drivers/mmc/host/litex_mmc.c:
>> - remove `linux/of.h` include, no longer needed since dropping
>> `of_match_ptr()`
>> - add `linux/mod_devicetable.h` include
>> - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate
>> the need to call mmc_free_host() explicitly during either probe()
>> error path or during remove()
>>
>>>New in v8:
>>> - remove `Cc:` lines from commit blurb
>>>drivers/mmc/host/litex_mmc.c:
>>> - fix file header comment (for real, this time)
>>> - add explicit `bits.h` include
>>> - remove `of_match_ptr()` wrapper from around .of_match_table argument
>>> - fix devm ordering issues: use `devm_request_irq()`, which precludes
>>> the need to call `free_irq()` on `probe()` error path or from `remove()`
>>>
>>>>New in v7:
>>>>drivers/mmc/host/Kconfig:
>>>> - added module name in LiteSDCard Kconfig entry
>>>>drivers/mmc/host/litex_mmc.c:
>>>> - fixed comment formatting, ordering, and capitalization throughout
>>>> the entire file
>>>> - sorted header #include statements
>>>> - removed redundant parantheses in readx_poll_timeout() condition
>>>> - explicit handling of readx_poll_timeout() timeout scenarios
>>>> - dev_err() used in litex_mmc_sdcard_wait_done()
>>>> - use memcpy_fromio() to grab command response
>>>> - no need to apply 0xffff mask to a 32-bit value right-shifted by 16
>>>> (host->resp[3])
>>>> - use clamp() instead of min(max(...)...)
>>>> - reworked platform_get_irq_optional() error handling logic
>>>> - no need to explicitly zero host->irq, kzalloc() does that already
>>>> - added missing free_irq() in litex_mmc_probe() error path
>>>> - reordered calls inside litex_mmc_remove() (calling mmc_free_host()
>>>> before free_irq()
>>>>
>>>>>New in v6:
>>>>> - fix handling of deferred probe vs. platform_get_irq_optional()
>>>>> - don't #ifdef dma_set_mask_and_coherent(), since it automatically
>>>>> does the right thing on both 32- and 64-bit DMA capable arches
>>>>> - remove MMC_CAP2_FULL_PWR_CYCLE, add MMC_CAP2_NO_MMC to list of
>>>>> hardcoded capabilities during litex_mmc_probe()
>>>>> - hardcode mmc->ocr_avail to the full 2.7-3.6V range allowed by the
>>>>> SDCard spec (the LiteSDCard device doesn't accept software
>>>>> configuration)
>>>>>
>>>>>>New in v5:
>>>>>> - shorter #define constant names (cosmetic, make them less unwieldy)
>>>>>> - picked up reviewed-by Joel
>>>>>>
>>>>>>>New in v4:
>>>>>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports
>>>>>>> no holes on either 32- or 64-bit builds
>>>>>>> - litex_mmc_set_bus_width() now encapsulates check for
>>>>>>> host->is_bus_width_set
>>>>>>> - litex_mmc_request() - factor out dma data setup into separate
>>>>>>> helper function: litex_mmc_do_dma()
>>>>>>>
>>>>>>>> New in v3:
>>>>>>>> - fixed function signature (no line split), and naming (litex_mmc_*)
>>>>>>>> - more informative MODULE_AUTHOR() entries
>>>>>>>> - also added matching "Copyright" entries in file header
>>>>>>>> - fixed description and dependencies in Kconfig
>>>>>>>> - removed magic constants
>>>>>>>> - removed litex_map_status(), have sdcard_wait_done() return *real*
>>>>>>>> error codes directly instead.
>>>>>>>> - streamlined litex_mmc_reponse_len()
>>>>>>>> - call litex_mmc_set_bus_width() only once, and ensure it returns
>>>>>>>> correct error code(s)
>>>>>>>> - use readx_poll_timeout() -- more concise -- instead of
>>>>>>>> read_poll_timeout()
>>>>>>>> - use dev_err() in litex_mmc_send_cmd() (instead of pr_err())
>>>>>>>> - litex_mmc_setclk() will update host->clock before returning
>>>>>>>> - separate irq initialization into its own function,
>>>>>>>> litex_mmc_irq_init()
>>>>>>>> - document rationale for f_min, f_max
>>>>>>>> - use dmam_alloc_coherent(), which simplifies cleanup significantly
>>>>>>>> - bump dma_set_mask_and_coherent() to 64-bits on suitable
>>>>>>>> architectures
>>>>>>>> - clock source picked up from dedicated DT clock reference property
>>>>>>>> - remove gpio card-detect logic (needs testing and a dt binding
>>>>>>>> example before being eligible for upstream inclusion)
>>>>>>>> - large `if (data) { ... }` block in litex_mmc_request() left as-is,
>>>>>>>> there are too many variables shared with the rest of the parent
>>>>>>>> function body to easily separate (e.g., `len`, `transfer`, `direct`).
>>>>>>>> If this is indeed a blocker, I can take another shot at refactoring
>>>>>>>> it in a future revision!
drivers/mmc/host/Kconfig | 9 +
drivers/mmc/host/Makefile | 1 +
drivers/mmc/host/litex_mmc.c | 657 +++++++++++++++++++++++++++++++++++
3 files changed, 667 insertions(+)
create mode 100644 drivers/mmc/host/litex_mmc.c
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 5af8494c31b5..8f661f52b502 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -1093,3 +1093,12 @@ config MMC_OWL
config MMC_SDHCI_EXTERNAL_DMA
bool
+
+config MMC_LITEX
+ tristate "LiteX MMC Host Controller support"
+ depends on ((PPC_MICROWATT || LITEX) && OF) || COMPILE_TEST
+ help
+ This selects support for the MMC Host Controller found in LiteX SoCs.
+
+ To compile this driver as a module, choose M here: the
+ module will be called litex_mmc.
diff --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 += -DDEBUG
diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c
new file mode 100644
index 000000000000..cc2848030e6b
--- /dev/null
+++ b/drivers/mmc/host/litex_mmc.c
@@ -0,0 +1,657 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * LiteX LiteSDCard driver
+ *
+ * Copyright (C) 2019-2020 Antmicro <[email protected]>
+ * Copyright (C) 2019-2020 Kamil Rakoczy <[email protected]>
+ * Copyright (C) 2019-2020 Maciej Dudek <[email protected]>
+ * Copyright (C) 2020 Paul Mackerras <[email protected]>
+ * Copyright (C) 2020-2022 Gabriel Somlo <[email protected]>
+ */
+
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/litex.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/sd.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_DATEVT 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 SD_CTL_DATA_XFER_NONE 0
+#define SD_CTL_DATA_XFER_READ 1
+#define SD_CTL_DATA_XFER_WRITE 2
+
+#define SD_CTL_RESP_NONE 0
+#define SD_CTL_RESP_SHORT 1
+#define SD_CTL_RESP_LONG 2
+#define SD_CTL_RESP_SHORT_BUSY 3
+
+#define SD_BIT_DONE BIT(0)
+#define SD_BIT_WR_ERR BIT(1)
+#define SD_BIT_TIMEOUT BIT(2)
+#define SD_BIT_CRC_ERR BIT(3)
+
+#define SD_SLEEP_US 5
+#define SD_TIMEOUT_US 20000
+
+#define SDIRQ_CARD_DETECT 1
+#define SDIRQ_SD_TO_MEM_DONE 2
+#define SDIRQ_MEM_TO_SD_DONE 4
+#define SDIRQ_CMD_DONE 8
+
+#define LITEX_MMC_OCR (MMC_VDD_27_28 | MMC_VDD_28_29 | MMC_VDD_29_30 | \
+ MMC_VDD_30_31 | MMC_VDD_31_32 | MMC_VDD_32_33 | \
+ MMC_VDD_33_34 | MMC_VDD_34_35 | MMC_VDD_35_36)
+
+struct litex_mmc_host {
+ struct mmc_host *mmc;
+
+ void __iomem *sdphy;
+ void __iomem *sdcore;
+ void __iomem *sdreader;
+ void __iomem *sdwriter;
+ void __iomem *sdirq;
+
+ void *buffer;
+ size_t buf_size;
+ dma_addr_t dma;
+
+ struct completion cmd_done;
+ int irq;
+
+ unsigned int ref_clk;
+ unsigned int sd_clk;
+
+ u32 resp[4];
+ u16 rca;
+
+ bool is_bus_width_set;
+ bool app_cmd;
+};
+
+static int litex_mmc_sdcard_wait_done(void __iomem *reg, struct device *dev)
+{
+ u8 evt;
+ int ret;
+
+ ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE,
+ SD_SLEEP_US, SD_TIMEOUT_US);
+ if (ret)
+ return ret;
+ if (evt == SD_BIT_DONE)
+ return 0;
+ if (evt & SD_BIT_WR_ERR)
+ return -EIO;
+ if (evt & SD_BIT_TIMEOUT)
+ return -ETIMEDOUT;
+ if (evt & SD_BIT_CRC_ERR)
+ return -EILSEQ;
+ dev_err(dev, "%s: unknown error (evt=%x)\n", __func__, evt);
+ return -EINVAL;
+}
+
+static int litex_mmc_send_cmd(struct litex_mmc_host *host,
+ u8 cmd, u32 arg, u8 response_len, u8 transfer)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ void __iomem *reg;
+ int ret;
+ u8 evt;
+
+ 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 != SD_CTL_DATA_XFER_NONE ||
+ response_len == SD_CTL_RESP_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);
+ }
+
+ ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_CMDEVT, dev);
+ if (ret) {
+ dev_err(dev, "Command (cmd %d) error, status %d\n", cmd, ret);
+ return ret;
+ }
+
+ if (response_len != SD_CTL_RESP_NONE) {
+ /*
+ * NOTE: this matches the semantics of litex_read32()
+ * regardless of underlying arch endianness!
+ */
+ memcpy_fromio(host->resp,
+ host->sdcore + LITEX_CORE_CMDRSP, 0x10);
+ }
+
+ if (!host->app_cmd && cmd == SD_SEND_RELATIVE_ADDR)
+ host->rca = (host->resp[3] >> 16);
+
+ host->app_cmd = (cmd == MMC_APP_CMD);
+
+ if (transfer == SD_CTL_DATA_XFER_NONE)
+ return ret; /* OK from prior litex_mmc_sdcard_wait_done() */
+
+ ret = litex_mmc_sdcard_wait_done(host->sdcore + LITEX_CORE_DATEVT, dev);
+ if (ret) {
+ dev_err(dev, "Data xfer (cmd %d) error, status %d\n", cmd, ret);
+ return ret;
+ }
+
+ /* Wait for completion of (read or write) DMA transfer */
+ reg = (transfer == SD_CTL_DATA_XFER_READ) ?
+ host->sdreader + LITEX_BLK2MEM_DONE :
+ host->sdwriter + LITEX_MEM2BLK_DONE;
+ ret = readx_poll_timeout(litex_read8, reg, evt, evt & SD_BIT_DONE,
+ SD_SLEEP_US, SD_TIMEOUT_US);
+ if (ret)
+ dev_err(dev, "DMA timeout (cmd %d)\n", cmd);
+
+ return ret;
+}
+
+static int litex_mmc_send_app_cmd(struct litex_mmc_host *host)
+{
+ return litex_mmc_send_cmd(host, MMC_APP_CMD, host->rca << 16,
+ SD_CTL_RESP_SHORT, SD_CTL_DATA_XFER_NONE);
+}
+
+static int litex_mmc_send_set_bus_w_cmd(struct litex_mmc_host *host, u32 width)
+{
+ return litex_mmc_send_cmd(host, SD_APP_SET_BUS_WIDTH, width,
+ SD_CTL_RESP_SHORT, SD_CTL_DATA_XFER_NONE);
+}
+
+static int litex_mmc_set_bus_width(struct litex_mmc_host *host)
+{
+ bool app_cmd_sent;
+ int ret;
+
+ if (host->is_bus_width_set)
+ return 0;
+
+ /* Ensure 'app_cmd' precedes 'app_set_bus_width_cmd' */
+ app_cmd_sent = host->app_cmd; /* was preceding command app_cmd? */
+ if (!app_cmd_sent) {
+ ret = litex_mmc_send_app_cmd(host);
+ if (ret)
+ return ret;
+ }
+
+ /* LiteSDCard only supports 4-bit bus width */
+ ret = litex_mmc_send_set_bus_w_cmd(host, MMC_BUS_WIDTH_4);
+ if (ret)
+ return ret;
+
+ /* Re-send 'app_cmd' if necessary */
+ if (app_cmd_sent) {
+ ret = litex_mmc_send_app_cmd(host);
+ if (ret)
+ return ret;
+ }
+
+ host->is_bus_width_set = true;
+
+ return 0;
+}
+
+static int litex_mmc_get_cd(struct mmc_host *mmc)
+{
+ struct litex_mmc_host *host = mmc_priv(mmc);
+ int ret;
+
+ if (!mmc_card_is_removable(mmc))
+ return 1;
+
+ ret = !litex_read8(host->sdphy + LITEX_PHY_CARDDETECT);
+ if (ret)
+ return ret;
+
+ /* Ensure bus width will be set (again) upon card (re)insertion */
+ host->is_bus_width_set = false;
+
+ return 0;
+}
+
+static irqreturn_t litex_mmc_interrupt(int irq, void *arg)
+{
+ struct mmc_host *mmc = arg;
+ struct litex_mmc_host *host = mmc_priv(mmc);
+ u32 pending = litex_read32(host->sdirq + LITEX_IRQ_PENDING);
+ irqreturn_t ret = IRQ_NONE;
+
+ /* Check for card change interrupt */
+ if (pending & SDIRQ_CARD_DETECT) {
+ litex_write32(host->sdirq + LITEX_IRQ_PENDING,
+ SDIRQ_CARD_DETECT);
+ mmc_detect_change(mmc, msecs_to_jiffies(10));
+ ret = IRQ_HANDLED;
+ }
+
+ /* Check for command completed */
+ if (pending & SDIRQ_CMD_DONE) {
+ /* Disable it so it doesn't keep interrupting */
+ litex_write32(host->sdirq + LITEX_IRQ_ENABLE,
+ SDIRQ_CARD_DETECT);
+ complete(&host->cmd_done);
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static u32 litex_mmc_response_len(struct mmc_command *cmd)
+{
+ if (cmd->flags & MMC_RSP_136)
+ return SD_CTL_RESP_LONG;
+ if (!(cmd->flags & MMC_RSP_PRESENT))
+ return SD_CTL_RESP_NONE;
+ if (cmd->flags & MMC_RSP_BUSY)
+ return SD_CTL_RESP_SHORT_BUSY;
+ return SD_CTL_RESP_SHORT;
+}
+
+static void litex_mmc_do_dma(struct litex_mmc_host *host, struct mmc_data *data,
+ unsigned int *len, bool *direct, u8 *transfer)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ dma_addr_t dma;
+ int sg_count;
+
+ /*
+ * Try to DMA directly to/from the data buffer.
+ * We can do that if the buffer can be mapped for DMA
+ * in one contiguous chunk.
+ */
+ dma = host->dma;
+ *len = data->blksz * data->blocks;
+ sg_count = dma_map_sg(dev, data->sg, data->sg_len,
+ mmc_get_dma_dir(data));
+ if (sg_count == 1) {
+ dma = sg_dma_address(data->sg);
+ *len = sg_dma_len(data->sg);
+ *direct = true;
+ } else if (*len > host->buf_size)
+ *len = host->buf_size;
+
+ if (data->flags & MMC_DATA_READ) {
+ litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
+ litex_write64(host->sdreader + LITEX_BLK2MEM_BASE, dma);
+ litex_write32(host->sdreader + LITEX_BLK2MEM_LEN, *len);
+ litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 1);
+ *transfer = SD_CTL_DATA_XFER_READ;
+ } else if (data->flags & MMC_DATA_WRITE) {
+ if (!*direct)
+ sg_copy_to_buffer(data->sg, data->sg_len,
+ host->buffer, *len);
+ litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
+ litex_write64(host->sdwriter + LITEX_MEM2BLK_BASE, dma);
+ litex_write32(host->sdwriter + LITEX_MEM2BLK_LEN, *len);
+ litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 1);
+ *transfer = SD_CTL_DATA_XFER_WRITE;
+ } else {
+ dev_warn(dev, "Data present w/o read or write flag.\n");
+ /* Continue: set cmd status, mark req done */
+ }
+
+ litex_write16(host->sdcore + LITEX_CORE_BLKLEN, data->blksz);
+ litex_write32(host->sdcore + LITEX_CORE_BLKCNT, data->blocks);
+}
+
+static void litex_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
+{
+ struct litex_mmc_host *host = mmc_priv(mmc);
+ struct device *dev = mmc_dev(mmc);
+ struct mmc_command *cmd = mrq->cmd;
+ struct mmc_command *sbc = mrq->sbc;
+ struct mmc_data *data = mrq->data;
+ struct mmc_command *stop = mrq->stop;
+ unsigned int retries = cmd->retries;
+ unsigned int len = 0;
+ bool direct = false;
+ u32 response_len = litex_mmc_response_len(cmd);
+ u8 transfer = SD_CTL_DATA_XFER_NONE;
+
+ /* First check that the card is still there */
+ if (!litex_mmc_get_cd(mmc)) {
+ cmd->error = -ENOMEDIUM;
+ mmc_request_done(mmc, mrq);
+ return;
+ }
+
+ /* Send set-block-count command if needed */
+ if (sbc) {
+ sbc->error = litex_mmc_send_cmd(host, sbc->opcode, sbc->arg,
+ litex_mmc_response_len(sbc),
+ SD_CTL_DATA_XFER_NONE);
+ if (sbc->error) {
+ host->is_bus_width_set = false;
+ mmc_request_done(mmc, mrq);
+ return;
+ }
+ }
+
+ if (data) {
+ /*
+ * LiteSDCard only supports 4-bit bus width; therefore, we MUST
+ * inject a SET_BUS_WIDTH (acmd6) before the very first data
+ * transfer, earlier than when the mmc subsystem would normally
+ * get around to it!
+ */
+ cmd->error = litex_mmc_set_bus_width(host);
+ if (cmd->error) {
+ dev_err(dev, "Can't set bus width!\n");
+ mmc_request_done(mmc, mrq);
+ return;
+ }
+
+ litex_mmc_do_dma(host, data, &len, &direct, &transfer);
+ }
+
+ do {
+ cmd->error = litex_mmc_send_cmd(host, cmd->opcode, cmd->arg,
+ response_len, transfer);
+ } while (cmd->error && retries-- > 0);
+
+ if (cmd->error) {
+ /* Card may be gone; don't assume bus width is still set */
+ host->is_bus_width_set = false;
+ }
+
+ if (response_len == SD_CTL_RESP_SHORT) {
+ /* Pull short response fields from appropriate host registers */
+ cmd->resp[0] = host->resp[3];
+ cmd->resp[1] = host->resp[2] & 0xFF;
+ } else if (response_len == SD_CTL_RESP_LONG) {
+ cmd->resp[0] = host->resp[0];
+ cmd->resp[1] = host->resp[1];
+ cmd->resp[2] = host->resp[2];
+ cmd->resp[3] = host->resp[3];
+ }
+
+ /* Send stop-transmission command if required */
+ if (stop && (cmd->error || !sbc)) {
+ stop->error = litex_mmc_send_cmd(host, stop->opcode, stop->arg,
+ litex_mmc_response_len(stop),
+ SD_CTL_DATA_XFER_NONE);
+ if (stop->error)
+ host->is_bus_width_set = false;
+ }
+
+ if (data) {
+ dma_unmap_sg(dev, data->sg, data->sg_len,
+ mmc_get_dma_dir(data));
+ }
+
+ if (!cmd->error && transfer != SD_CTL_DATA_XFER_NONE) {
+ data->bytes_xfered = min(len, mmc->max_req_size);
+ if (transfer == SD_CTL_DATA_XFER_READ && !direct) {
+ sg_copy_from_buffer(data->sg, sg_nents(data->sg),
+ host->buffer, data->bytes_xfered);
+ }
+ }
+
+ mmc_request_done(mmc, mrq);
+}
+
+static void litex_mmc_setclk(struct litex_mmc_host *host, unsigned int freq)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ u32 div;
+
+ div = freq ? host->ref_clk / freq : 256U;
+ div = roundup_pow_of_two(div);
+ div = clamp(div, 2U, 256U);
+ dev_dbg(dev, "sd_clk_freq=%d: set to %d via div=%d\n",
+ freq, host->ref_clk / div, div);
+ litex_write16(host->sdphy + LITEX_PHY_CLOCKERDIV, div);
+ host->sd_clk = freq;
+}
+
+static void litex_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
+{
+ struct litex_mmc_host *host = mmc_priv(mmc);
+
+ /*
+ * NOTE: Ignore any ios->bus_width updates; they occur right after
+ * the mmc core sends its own acmd6 bus-width change notification,
+ * which is redundant since we snoop on the command flow and inject
+ * an early acmd6 before the first data transfer command is sent!
+ */
+
+ /* Update sd_clk */
+ if (ios->clock != host->sd_clk)
+ litex_mmc_setclk(host, ios->clock);
+}
+
+static const struct mmc_host_ops litex_mmc_ops = {
+ .get_cd = litex_mmc_get_cd,
+ .request = litex_mmc_request,
+ .set_ios = litex_mmc_set_ios,
+};
+
+static int litex_mmc_irq_init(struct platform_device *pdev,
+ struct litex_mmc_host *host)
+{
+ struct device *dev = mmc_dev(host->mmc);
+ int ret;
+
+ ret = platform_get_irq_optional(pdev, 0);
+ if (ret < 0 && ret != -ENXIO)
+ return ret;
+ if (ret > 0)
+ host->irq = ret;
+ else {
+ dev_warn(dev, "Failed to get IRQ, using polling\n");
+ goto use_polling;
+ }
+
+ host->sdirq = devm_platform_ioremap_resource_byname(pdev, "irq");
+ if (IS_ERR(host->sdirq))
+ return PTR_ERR(host->sdirq);
+
+ ret = devm_request_irq(dev, host->irq, litex_mmc_interrupt, 0,
+ "litex-mmc", host->mmc);
+ if (ret < 0) {
+ dev_warn(dev, "IRQ request error %d, using polling\n", ret);
+ goto use_polling;
+ }
+
+ /* Clear & enable card-change interrupts */
+ litex_write32(host->sdirq + LITEX_IRQ_PENDING, SDIRQ_CARD_DETECT);
+ litex_write32(host->sdirq + LITEX_IRQ_ENABLE, SDIRQ_CARD_DETECT);
+
+ return 0;
+
+use_polling:
+ host->mmc->caps |= MMC_CAP_NEEDS_POLL;
+ return 0;
+}
+
+static void litex_mmc_free_host_wrapper(void *mmc)
+{
+ mmc_free_host(mmc);
+}
+
+static int litex_mmc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct litex_mmc_host *host;
+ struct mmc_host *mmc;
+ struct clk *clk;
+ int ret;
+
+ /*
+ * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512,
+ * and max_blk_count accordingly set to 8;
+ * If for some reason we need to modify max_blk_count, we must also
+ * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;`
+ */
+ mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), dev);
+ if (!mmc)
+ return -ENOMEM;
+
+ ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Can't register mmc_free_host action\n");
+
+ host = mmc_priv(mmc);
+ host->mmc = mmc;
+
+ /* Initialize clock source */
+ clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(clk))
+ return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n");
+ host->ref_clk = clk_get_rate(clk);
+ host->sd_clk = 0;
+
+ /*
+ * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject
+ * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier
+ * than when the mmc subsystem would normally get around to it!
+ */
+ host->is_bus_width_set = false;
+ host->app_cmd = false;
+
+ /* LiteSDCard can support 64-bit DMA addressing */
+ ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+ if (ret)
+ return ret;
+
+ host->buf_size = mmc->max_req_size * 2;
+ host->buffer = dmam_alloc_coherent(dev, host->buf_size,
+ &host->dma, GFP_KERNEL);
+ if (host->buffer == NULL)
+ return -ENOMEM;
+
+ host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy");
+ if (IS_ERR(host->sdphy))
+ return PTR_ERR(host->sdphy);
+
+ host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core");
+ if (IS_ERR(host->sdcore))
+ return PTR_ERR(host->sdcore);
+
+ host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader");
+ if (IS_ERR(host->sdreader))
+ return PTR_ERR(host->sdreader);
+
+ host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer");
+ if (IS_ERR(host->sdwriter))
+ return PTR_ERR(host->sdwriter);
+
+ /* Ensure DMA bus masters are disabled */
+ litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
+ litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
+
+ init_completion(&host->cmd_done);
+ ret = litex_mmc_irq_init(pdev, host);
+ if (ret)
+ return ret;
+
+ /* Allow full generic 2.7-3.6V range; no software tuning available */
+ mmc->ocr_avail = LITEX_MMC_OCR;
+
+ mmc->ops = &litex_mmc_ops;
+
+ /*
+ * Set default sd_clk frequency range based on empirical observations
+ * of LiteSDCard gateware behavior on typical SDCard media
+ */
+ mmc->f_min = 12.5e6;
+ mmc->f_max = 50e6;
+
+ ret = mmc_of_parse(mmc);
+ if (ret)
+ return ret;
+
+ /* Force 4-bit bus_width (only width supported by hardware) */
+ mmc->caps &= ~MMC_CAP_8_BIT_DATA;
+ mmc->caps |= MMC_CAP_4_BIT_DATA;
+
+ /* Set default capabilities */
+ mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY |
+ MMC_CAP_DRIVER_TYPE_D |
+ MMC_CAP_CMD23;
+ mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT |
+ MMC_CAP2_NO_SDIO |
+ MMC_CAP2_NO_MMC;
+
+ platform_set_drvdata(pdev, host);
+
+ return mmc_add_host(mmc);
+}
+
+static int litex_mmc_remove(struct platform_device *pdev)
+{
+ struct litex_mmc_host *host = platform_get_drvdata(pdev);
+
+ mmc_remove_host(host->mmc);
+ return 0;
+}
+
+static const struct of_device_id litex_match[] = {
+ { .compatible = "litex,mmc" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, litex_match);
+
+static struct platform_driver litex_mmc_driver = {
+ .probe = litex_mmc_probe,
+ .remove = litex_mmc_remove,
+ .driver = {
+ .name = "litex-mmc",
+ .of_match_table = litex_match,
+ },
+};
+module_platform_driver(litex_mmc_driver);
+
+MODULE_DESCRIPTION("LiteX SDCard driver");
+MODULE_AUTHOR("Antmicro <[email protected]>");
+MODULE_AUTHOR("Kamil Rakoczy <[email protected]>");
+MODULE_AUTHOR("Maciej Dudek <[email protected]>");
+MODULE_AUTHOR("Paul Mackerras <[email protected]>");
+MODULE_AUTHOR("Gabriel Somlo <[email protected]>");
+MODULE_LICENSE("GPL v2");
--
2.31.1
On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote:
> 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 <[email protected]>
> Signed-off-by: Kamil Rakoczy <[email protected]>
> Co-developed-by: Maciej Dudek <[email protected]>
> Signed-off-by: Maciej Dudek <[email protected]>
> Co-developed-by: Paul Mackerras <[email protected]>
> Signed-off-by: Paul Mackerras <[email protected]>
> Signed-off-by: Gabriel Somlo <[email protected]>
> Reviewed-by: Joel Stanley <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
> ---
>
> New in v11:
> - picked up r/b from Andy
> drivers/mmc/host/litex_mmc.c:
> - defensive coding of litex_mmc_interrupt() return logic
> - remove `dev` member of `struct litex_mmc_host`, only used during probe
>
> >New in v10:
> >drivers/mmc/host/litex_mmc.c:
> > - group `linux/mmc/*` includes by themselves
> > - clean-up of `return` style (multiple locations throughout source)
> > - create `mmc_free_host()` wrapper for use with
> > `devm_add_action_or_reset()`
> > - use GFP_KERNEL with `dmam_alloc_coherent()`
> >
> >>New in v9:
> >>drivers/mmc/host/Kconfig:
> >> - fix OF dependency
> >>drivers/mmc/host/litex_mmc.c:
> >> - remove `linux/of.h` include, no longer needed since dropping
> >> `of_match_ptr()`
> >> - add `linux/mod_devicetable.h` include
> >> - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate
> >> the need to call mmc_free_host() explicitly during either probe()
> >> error path or during remove()
> >>
> >>>New in v8:
> >>> - remove `Cc:` lines from commit blurb
> >>>drivers/mmc/host/litex_mmc.c:
> >>> - fix file header comment (for real, this time)
> >>> - add explicit `bits.h` include
> >>> - remove `of_match_ptr()` wrapper from around .of_match_table argument
> >>> - fix devm ordering issues: use `devm_request_irq()`, which precludes
> >>> the need to call `free_irq()` on `probe()` error path or from `remove()`
> >>>
> >>>>New in v7:
> >>>>drivers/mmc/host/Kconfig:
> >>>> - added module name in LiteSDCard Kconfig entry
> >>>>drivers/mmc/host/litex_mmc.c:
> >>>> - fixed comment formatting, ordering, and capitalization throughout
> >>>> the entire file
> >>>> - sorted header #include statements
> >>>> - removed redundant parantheses in readx_poll_timeout() condition
> >>>> - explicit handling of readx_poll_timeout() timeout scenarios
> >>>> - dev_err() used in litex_mmc_sdcard_wait_done()
> >>>> - use memcpy_fromio() to grab command response
> >>>> - no need to apply 0xffff mask to a 32-bit value right-shifted by 16
> >>>> (host->resp[3])
> >>>> - use clamp() instead of min(max(...)...)
> >>>> - reworked platform_get_irq_optional() error handling logic
> >>>> - no need to explicitly zero host->irq, kzalloc() does that already
> >>>> - added missing free_irq() in litex_mmc_probe() error path
> >>>> - reordered calls inside litex_mmc_remove() (calling mmc_free_host()
> >>>> before free_irq()
> >>>>
> >>>>>New in v6:
> >>>>> - fix handling of deferred probe vs. platform_get_irq_optional()
> >>>>> - don't #ifdef dma_set_mask_and_coherent(), since it automatically
> >>>>> does the right thing on both 32- and 64-bit DMA capable arches
> >>>>> - remove MMC_CAP2_FULL_PWR_CYCLE, add MMC_CAP2_NO_MMC to list of
> >>>>> hardcoded capabilities during litex_mmc_probe()
> >>>>> - hardcode mmc->ocr_avail to the full 2.7-3.6V range allowed by the
> >>>>> SDCard spec (the LiteSDCard device doesn't accept software
> >>>>> configuration)
> >>>>>
> >>>>>>New in v5:
> >>>>>> - shorter #define constant names (cosmetic, make them less unwieldy)
> >>>>>> - picked up reviewed-by Joel
> >>>>>>
> >>>>>>>New in v4:
> >>>>>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports
> >>>>>>> no holes on either 32- or 64-bit builds
> >>>>>>> - litex_mmc_set_bus_width() now encapsulates check for
> >>>>>>> host->is_bus_width_set
> >>>>>>> - litex_mmc_request() - factor out dma data setup into separate
> >>>>>>> helper function: litex_mmc_do_dma()
> >>>>>>>
> >>>>>>>> New in v3:
> >>>>>>>> - fixed function signature (no line split), and naming (litex_mmc_*)
> >>>>>>>> - more informative MODULE_AUTHOR() entries
> >>>>>>>> - also added matching "Copyright" entries in file header
> >>>>>>>> - fixed description and dependencies in Kconfig
> >>>>>>>> - removed magic constants
> >>>>>>>> - removed litex_map_status(), have sdcard_wait_done() return *real*
> >>>>>>>> error codes directly instead.
> >>>>>>>> - streamlined litex_mmc_reponse_len()
> >>>>>>>> - call litex_mmc_set_bus_width() only once, and ensure it returns
> >>>>>>>> correct error code(s)
> >>>>>>>> - use readx_poll_timeout() -- more concise -- instead of
> >>>>>>>> read_poll_timeout()
> >>>>>>>> - use dev_err() in litex_mmc_send_cmd() (instead of pr_err())
> >>>>>>>> - litex_mmc_setclk() will update host->clock before returning
> >>>>>>>> - separate irq initialization into its own function,
> >>>>>>>> litex_mmc_irq_init()
> >>>>>>>> - document rationale for f_min, f_max
> >>>>>>>> - use dmam_alloc_coherent(), which simplifies cleanup significantly
> >>>>>>>> - bump dma_set_mask_and_coherent() to 64-bits on suitable
> >>>>>>>> architectures
> >>>>>>>> - clock source picked up from dedicated DT clock reference property
> >>>>>>>> - remove gpio card-detect logic (needs testing and a dt binding
> >>>>>>>> example before being eligible for upstream inclusion)
> >>>>>>>> - large `if (data) { ... }` block in litex_mmc_request() left as-is,
> >>>>>>>> there are too many variables shared with the rest of the parent
> >>>>>>>> function body to easily separate (e.g., `len`, `transfer`, `direct`).
> >>>>>>>> If this is indeed a blocker, I can take another shot at refactoring
> >>>>>>>> it in a future revision!
>
> drivers/mmc/host/Kconfig | 9 +
> drivers/mmc/host/Makefile | 1 +
> drivers/mmc/host/litex_mmc.c | 657 +++++++++++++++++++++++++++++++++++
> 3 files changed, 667 insertions(+)
> create mode 100644 drivers/mmc/host/litex_mmc.c
>
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index 5af8494c31b5..8f661f52b502 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -1093,3 +1093,12 @@ config MMC_OWL
>
> config MMC_SDHCI_EXTERNAL_DMA
> bool
> +
> +config MMC_LITEX
> + tristate "LiteX MMC Host Controller support"
> + depends on ((PPC_MICROWATT || LITEX) && OF) || COMPILE_TEST
> + help
> + This selects support for the MMC Host Controller found in LiteX SoCs.
See comment below.
> + To compile this driver as a module, choose M here: the
> + module will be called litex_mmc.
Can we add this here too?
If unsure, say N.
> diff --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 += -DDEBUG
> diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c
> new file mode 100644
> index 000000000000..cc2848030e6b
> --- /dev/null
> +++ b/drivers/mmc/host/litex_mmc.c
> @@ -0,0 +1,657 @@
...
> +
> + /* Initialize clock source */
> + clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(clk))
> + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n");
> + host->ref_clk = clk_get_rate(clk);
Note, we used to have:
cpu = of_get_next_cpu_node(NULL);
ret = of_property_read_u32(cpu, "clock-frequency", &host->freq);
of_node_put(cpu);
if (ret) {
dev_err(&pdev->dev, "No \"clock-frequency\" property in DT\n");
goto err_free_host;
}
As we agree, this worked but was hacky. The new use of devm_clk_get above uses
the COMMON_CLK framework. Which is great but OpenRISC doesn't yet support
COMMON_CLK, so this driver no longer works on OpenRISC.
I think the ideal thing is to not change the driver code and I will just add
support for COMMON_CLK on openrisc (already done and tested). But as we
discussed off e-mail I think we should change the config constraints to.
depends on ((PPC_MICROWATT || LITEX) && OF && HAVE_CLK) || COMPILE_TEST
-Stafford
On Tue, Jan 11, 2022 at 07:07:47AM +0900, Stafford Horne wrote:
> On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote:
> > 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 <[email protected]>
> > Signed-off-by: Kamil Rakoczy <[email protected]>
> > Co-developed-by: Maciej Dudek <[email protected]>
> > Signed-off-by: Maciej Dudek <[email protected]>
> > Co-developed-by: Paul Mackerras <[email protected]>
> > Signed-off-by: Paul Mackerras <[email protected]>
> > Signed-off-by: Gabriel Somlo <[email protected]>
> > Reviewed-by: Joel Stanley <[email protected]>
> > Reviewed-by: Andy Shevchenko <[email protected]>
> > ---
> >
> > New in v11:
> > - picked up r/b from Andy
> > drivers/mmc/host/litex_mmc.c:
> > - defensive coding of litex_mmc_interrupt() return logic
> > - remove `dev` member of `struct litex_mmc_host`, only used during probe
> >
> > >New in v10:
> > >drivers/mmc/host/litex_mmc.c:
> > > - group `linux/mmc/*` includes by themselves
> > > - clean-up of `return` style (multiple locations throughout source)
> > > - create `mmc_free_host()` wrapper for use with
> > > `devm_add_action_or_reset()`
> > > - use GFP_KERNEL with `dmam_alloc_coherent()`
> > >
> > >>New in v9:
> > >>drivers/mmc/host/Kconfig:
> > >> - fix OF dependency
> > >>drivers/mmc/host/litex_mmc.c:
> > >> - remove `linux/of.h` include, no longer needed since dropping
> > >> `of_match_ptr()`
> > >> - add `linux/mod_devicetable.h` include
> > >> - use devm_action_or_reset() to devm-ify mmc_alloc_host(), and obviate
> > >> the need to call mmc_free_host() explicitly during either probe()
> > >> error path or during remove()
> > >>
> > >>>New in v8:
> > >>> - remove `Cc:` lines from commit blurb
> > >>>drivers/mmc/host/litex_mmc.c:
> > >>> - fix file header comment (for real, this time)
> > >>> - add explicit `bits.h` include
> > >>> - remove `of_match_ptr()` wrapper from around .of_match_table argument
> > >>> - fix devm ordering issues: use `devm_request_irq()`, which precludes
> > >>> the need to call `free_irq()` on `probe()` error path or from `remove()`
> > >>>
> > >>>>New in v7:
> > >>>>drivers/mmc/host/Kconfig:
> > >>>> - added module name in LiteSDCard Kconfig entry
> > >>>>drivers/mmc/host/litex_mmc.c:
> > >>>> - fixed comment formatting, ordering, and capitalization throughout
> > >>>> the entire file
> > >>>> - sorted header #include statements
> > >>>> - removed redundant parantheses in readx_poll_timeout() condition
> > >>>> - explicit handling of readx_poll_timeout() timeout scenarios
> > >>>> - dev_err() used in litex_mmc_sdcard_wait_done()
> > >>>> - use memcpy_fromio() to grab command response
> > >>>> - no need to apply 0xffff mask to a 32-bit value right-shifted by 16
> > >>>> (host->resp[3])
> > >>>> - use clamp() instead of min(max(...)...)
> > >>>> - reworked platform_get_irq_optional() error handling logic
> > >>>> - no need to explicitly zero host->irq, kzalloc() does that already
> > >>>> - added missing free_irq() in litex_mmc_probe() error path
> > >>>> - reordered calls inside litex_mmc_remove() (calling mmc_free_host()
> > >>>> before free_irq()
> > >>>>
> > >>>>>New in v6:
> > >>>>> - fix handling of deferred probe vs. platform_get_irq_optional()
> > >>>>> - don't #ifdef dma_set_mask_and_coherent(), since it automatically
> > >>>>> does the right thing on both 32- and 64-bit DMA capable arches
> > >>>>> - remove MMC_CAP2_FULL_PWR_CYCLE, add MMC_CAP2_NO_MMC to list of
> > >>>>> hardcoded capabilities during litex_mmc_probe()
> > >>>>> - hardcode mmc->ocr_avail to the full 2.7-3.6V range allowed by the
> > >>>>> SDCard spec (the LiteSDCard device doesn't accept software
> > >>>>> configuration)
> > >>>>>
> > >>>>>>New in v5:
> > >>>>>> - shorter #define constant names (cosmetic, make them less unwieldy)
> > >>>>>> - picked up reviewed-by Joel
> > >>>>>>
> > >>>>>>>New in v4:
> > >>>>>>> - struct litex_mmc_host fields re-ordered so that `pahole` reports
> > >>>>>>> no holes on either 32- or 64-bit builds
> > >>>>>>> - litex_mmc_set_bus_width() now encapsulates check for
> > >>>>>>> host->is_bus_width_set
> > >>>>>>> - litex_mmc_request() - factor out dma data setup into separate
> > >>>>>>> helper function: litex_mmc_do_dma()
> > >>>>>>>
> > >>>>>>>> New in v3:
> > >>>>>>>> - fixed function signature (no line split), and naming (litex_mmc_*)
> > >>>>>>>> - more informative MODULE_AUTHOR() entries
> > >>>>>>>> - also added matching "Copyright" entries in file header
> > >>>>>>>> - fixed description and dependencies in Kconfig
> > >>>>>>>> - removed magic constants
> > >>>>>>>> - removed litex_map_status(), have sdcard_wait_done() return *real*
> > >>>>>>>> error codes directly instead.
> > >>>>>>>> - streamlined litex_mmc_reponse_len()
> > >>>>>>>> - call litex_mmc_set_bus_width() only once, and ensure it returns
> > >>>>>>>> correct error code(s)
> > >>>>>>>> - use readx_poll_timeout() -- more concise -- instead of
> > >>>>>>>> read_poll_timeout()
> > >>>>>>>> - use dev_err() in litex_mmc_send_cmd() (instead of pr_err())
> > >>>>>>>> - litex_mmc_setclk() will update host->clock before returning
> > >>>>>>>> - separate irq initialization into its own function,
> > >>>>>>>> litex_mmc_irq_init()
> > >>>>>>>> - document rationale for f_min, f_max
> > >>>>>>>> - use dmam_alloc_coherent(), which simplifies cleanup significantly
> > >>>>>>>> - bump dma_set_mask_and_coherent() to 64-bits on suitable
> > >>>>>>>> architectures
> > >>>>>>>> - clock source picked up from dedicated DT clock reference property
> > >>>>>>>> - remove gpio card-detect logic (needs testing and a dt binding
> > >>>>>>>> example before being eligible for upstream inclusion)
> > >>>>>>>> - large `if (data) { ... }` block in litex_mmc_request() left as-is,
> > >>>>>>>> there are too many variables shared with the rest of the parent
> > >>>>>>>> function body to easily separate (e.g., `len`, `transfer`, `direct`).
> > >>>>>>>> If this is indeed a blocker, I can take another shot at refactoring
> > >>>>>>>> it in a future revision!
> >
> > drivers/mmc/host/Kconfig | 9 +
> > drivers/mmc/host/Makefile | 1 +
> > drivers/mmc/host/litex_mmc.c | 657 +++++++++++++++++++++++++++++++++++
> > 3 files changed, 667 insertions(+)
> > create mode 100644 drivers/mmc/host/litex_mmc.c
> >
> > diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> > index 5af8494c31b5..8f661f52b502 100644
> > --- a/drivers/mmc/host/Kconfig
> > +++ b/drivers/mmc/host/Kconfig
> > @@ -1093,3 +1093,12 @@ config MMC_OWL
> >
> > config MMC_SDHCI_EXTERNAL_DMA
> > bool
> > +
> > +config MMC_LITEX
> > + tristate "LiteX MMC Host Controller support"
> > + depends on ((PPC_MICROWATT || LITEX) && OF) || COMPILE_TEST
> > + help
> > + This selects support for the MMC Host Controller found in LiteX SoCs.
>
> See comment below.
>
> > + To compile this driver as a module, choose M here: the
> > + module will be called litex_mmc.
>
> Can we add this here too?
>
> If unsure, say N.
OK, lined up for v12.
> > diff --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 += -DDEBUG
> > diff --git a/drivers/mmc/host/litex_mmc.c b/drivers/mmc/host/litex_mmc.c
> > new file mode 100644
> > index 000000000000..cc2848030e6b
> > --- /dev/null
> > +++ b/drivers/mmc/host/litex_mmc.c
> > @@ -0,0 +1,657 @@
> ...
> > +
> > + /* Initialize clock source */
> > + clk = devm_clk_get(dev, NULL);
> > + if (IS_ERR(clk))
> > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n");
> > + host->ref_clk = clk_get_rate(clk);
>
> Note, we used to have:
>
> cpu = of_get_next_cpu_node(NULL);
> ret = of_property_read_u32(cpu, "clock-frequency", &host->freq);
> of_node_put(cpu);
> if (ret) {
> dev_err(&pdev->dev, "No \"clock-frequency\" property in DT\n");
> goto err_free_host;
> }
>
> As we agree, this worked but was hacky. The new use of devm_clk_get above uses
> the COMMON_CLK framework. Which is great but OpenRISC doesn't yet support
> COMMON_CLK, so this driver no longer works on OpenRISC.
>
> I think the ideal thing is to not change the driver code and I will just add
> support for COMMON_CLK on openrisc (already done and tested). But as we
> discussed off e-mail I think we should change the config constraints to.
>
> depends on ((PPC_MICROWATT || LITEX) && OF && HAVE_CLK) || COMPILE_TEST
OK, also lined up for v12.
I'll probably send out v12 in a few hours -- thanks for the
suggestions and testing!
Best,
--Gabriel
On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote:
> 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 <[email protected]>
> Signed-off-by: Kamil Rakoczy <[email protected]>
> Co-developed-by: Maciej Dudek <[email protected]>
> Signed-off-by: Maciej Dudek <[email protected]>
> Co-developed-by: Paul Mackerras <[email protected]>
> Signed-off-by: Paul Mackerras <[email protected]>
> Signed-off-by: Gabriel Somlo <[email protected]>
> Reviewed-by: Joel Stanley <[email protected]>
> Reviewed-by: Andy Shevchenko <[email protected]>
> ---
>
...
> +static int litex_mmc_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct litex_mmc_host *host;
> + struct mmc_host *mmc;
> + struct clk *clk;
> + int ret;
> +
> + /*
> + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512,
> + * and max_blk_count accordingly set to 8;
> + * If for some reason we need to modify max_blk_count, we must also
> + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;`
> + */
> + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), dev);
> + if (!mmc)
> + return -ENOMEM;
> +
> + ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "Can't register mmc_free_host action\n");
> +
> + host = mmc_priv(mmc);
> + host->mmc = mmc;
> +
> + /* Initialize clock source */
> + clk = devm_clk_get(dev, NULL);
> + if (IS_ERR(clk))
> + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n");
> + host->ref_clk = clk_get_rate(clk);
> + host->sd_clk = 0;
> +
> + /*
> + * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject
> + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier
> + * than when the mmc subsystem would normally get around to it!
> + */
> + host->is_bus_width_set = false;
> + host->app_cmd = false;
> +
> + /* LiteSDCard can support 64-bit DMA addressing */
> + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> + if (ret)
> + return ret;
> +
> + host->buf_size = mmc->max_req_size * 2;
> + host->buffer = dmam_alloc_coherent(dev, host->buf_size,
> + &host->dma, GFP_KERNEL);
> + if (host->buffer == NULL)
> + return -ENOMEM;
> +
> + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy");
> + if (IS_ERR(host->sdphy))
> + return PTR_ERR(host->sdphy);
> +
> + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core");
> + if (IS_ERR(host->sdcore))
> + return PTR_ERR(host->sdcore);
> +
> + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader");
> + if (IS_ERR(host->sdreader))
> + return PTR_ERR(host->sdreader);
> +
> + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer");
> + if (IS_ERR(host->sdwriter))
> + return PTR_ERR(host->sdwriter);
> +
> + /* Ensure DMA bus masters are disabled */
> + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
> + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
> +
> + init_completion(&host->cmd_done);
> + ret = litex_mmc_irq_init(pdev, host);
> + if (ret)
> + return ret;
> +
> + /* Allow full generic 2.7-3.6V range; no software tuning available */
> + mmc->ocr_avail = LITEX_MMC_OCR;
> +
> + mmc->ops = &litex_mmc_ops;
> +
> + /*
> + * Set default sd_clk frequency range based on empirical observations
> + * of LiteSDCard gateware behavior on typical SDCard media
> + */
> + mmc->f_min = 12.5e6;
> + mmc->f_max = 50e6;
> +
> + ret = mmc_of_parse(mmc);
> + if (ret)
> + return ret;
> +
> + /* Force 4-bit bus_width (only width supported by hardware) */
> + mmc->caps &= ~MMC_CAP_8_BIT_DATA;
> + mmc->caps |= MMC_CAP_4_BIT_DATA;
> +
> + /* Set default capabilities */
> + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY |
> + MMC_CAP_DRIVER_TYPE_D |
> + MMC_CAP_CMD23;
> + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT |
> + MMC_CAP2_NO_SDIO |
> + MMC_CAP2_NO_MMC;
> +
> + platform_set_drvdata(pdev, host);
One more thing here. Or somewhere, should we add:
dev_info(dev, "Litex MMC controller initialized");
I was having a hard time debugging probing of this and having no printk's made
it a bit difficult.
Though I was able to get most of the debug statements I needed using:
"debug initcall_debug dyndbg=\"file drivers/* +p\" loglevel=8"
-Stafford
> + return mmc_add_host(mmc);
> +}
> +
On Tue, Jan 11, 2022 at 07:15:42AM +0900, Stafford Horne wrote:
> On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote:
> > 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 <[email protected]>
> > Signed-off-by: Kamil Rakoczy <[email protected]>
> > Co-developed-by: Maciej Dudek <[email protected]>
> > Signed-off-by: Maciej Dudek <[email protected]>
> > Co-developed-by: Paul Mackerras <[email protected]>
> > Signed-off-by: Paul Mackerras <[email protected]>
> > Signed-off-by: Gabriel Somlo <[email protected]>
> > Reviewed-by: Joel Stanley <[email protected]>
> > Reviewed-by: Andy Shevchenko <[email protected]>
> > ---
> >
> ...
> > +static int litex_mmc_probe(struct platform_device *pdev)
> > +{
> > + struct device *dev = &pdev->dev;
> > + struct litex_mmc_host *host;
> > + struct mmc_host *mmc;
> > + struct clk *clk;
> > + int ret;
> > +
> > + /*
> > + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512,
> > + * and max_blk_count accordingly set to 8;
> > + * If for some reason we need to modify max_blk_count, we must also
> > + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;`
> > + */
> > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), dev);
> > + if (!mmc)
> > + return -ENOMEM;
> > +
> > + ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc);
> > + if (ret)
> > + return dev_err_probe(dev, ret,
> > + "Can't register mmc_free_host action\n");
> > +
> > + host = mmc_priv(mmc);
> > + host->mmc = mmc;
> > +
> > + /* Initialize clock source */
> > + clk = devm_clk_get(dev, NULL);
> > + if (IS_ERR(clk))
> > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n");
> > + host->ref_clk = clk_get_rate(clk);
> > + host->sd_clk = 0;
> > +
> > + /*
> > + * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject
> > + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier
> > + * than when the mmc subsystem would normally get around to it!
> > + */
> > + host->is_bus_width_set = false;
> > + host->app_cmd = false;
> > +
> > + /* LiteSDCard can support 64-bit DMA addressing */
> > + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> > + if (ret)
> > + return ret;
> > +
> > + host->buf_size = mmc->max_req_size * 2;
> > + host->buffer = dmam_alloc_coherent(dev, host->buf_size,
> > + &host->dma, GFP_KERNEL);
> > + if (host->buffer == NULL)
> > + return -ENOMEM;
> > +
> > + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy");
> > + if (IS_ERR(host->sdphy))
> > + return PTR_ERR(host->sdphy);
> > +
> > + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core");
> > + if (IS_ERR(host->sdcore))
> > + return PTR_ERR(host->sdcore);
> > +
> > + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader");
> > + if (IS_ERR(host->sdreader))
> > + return PTR_ERR(host->sdreader);
> > +
> > + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer");
> > + if (IS_ERR(host->sdwriter))
> > + return PTR_ERR(host->sdwriter);
> > +
> > + /* Ensure DMA bus masters are disabled */
> > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
> > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
> > +
> > + init_completion(&host->cmd_done);
> > + ret = litex_mmc_irq_init(pdev, host);
> > + if (ret)
> > + return ret;
> > +
> > + /* Allow full generic 2.7-3.6V range; no software tuning available */
> > + mmc->ocr_avail = LITEX_MMC_OCR;
> > +
> > + mmc->ops = &litex_mmc_ops;
> > +
> > + /*
> > + * Set default sd_clk frequency range based on empirical observations
> > + * of LiteSDCard gateware behavior on typical SDCard media
> > + */
> > + mmc->f_min = 12.5e6;
> > + mmc->f_max = 50e6;
> > +
> > + ret = mmc_of_parse(mmc);
> > + if (ret)
> > + return ret;
> > +
> > + /* Force 4-bit bus_width (only width supported by hardware) */
> > + mmc->caps &= ~MMC_CAP_8_BIT_DATA;
> > + mmc->caps |= MMC_CAP_4_BIT_DATA;
> > +
> > + /* Set default capabilities */
> > + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY |
> > + MMC_CAP_DRIVER_TYPE_D |
> > + MMC_CAP_CMD23;
> > + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT |
> > + MMC_CAP2_NO_SDIO |
> > + MMC_CAP2_NO_MMC;
> > +
> > + platform_set_drvdata(pdev, host);
>
> One more thing here. Or somewhere, should we add:
>
> dev_info(dev, "Litex MMC controller initialized");
>
> I was having a hard time debugging probing of this and having no printk's made
> it a bit difficult.
>
> Though I was able to get most of the debug statements I needed using:
>
> "debug initcall_debug dyndbg=\"file drivers/* +p\" loglevel=8"
>
> -Stafford
>
> > + return mmc_add_host(mmc);
I'd prefer to declare victory *after* calling mmc_add_host(), so if
there are no objections I'd prefer to do the following in v12:
...
platform_set_drvdata(pdev, host);
- return mmc_add_host(mmc);
+ ret = mmc_add_host(mmc);
+ if (ret)
+ return dev_err_probe(dev, ret, "LiteX MMC probe failed!\n");
+
+ dev_info(dev, "LiteX MMC controller initialized.\n");
+
+ return 0;
}
Thanks,
--Gabriel
On Mon, Jan 10, 2022 at 05:39:36PM -0500, Gabriel L. Somlo wrote:
> On Tue, Jan 11, 2022 at 07:15:42AM +0900, Stafford Horne wrote:
> > On Sun, Jan 09, 2022 at 06:20:03PM -0500, Gabriel Somlo wrote:
> > > 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 <[email protected]>
> > > Signed-off-by: Kamil Rakoczy <[email protected]>
> > > Co-developed-by: Maciej Dudek <[email protected]>
> > > Signed-off-by: Maciej Dudek <[email protected]>
> > > Co-developed-by: Paul Mackerras <[email protected]>
> > > Signed-off-by: Paul Mackerras <[email protected]>
> > > Signed-off-by: Gabriel Somlo <[email protected]>
> > > Reviewed-by: Joel Stanley <[email protected]>
> > > Reviewed-by: Andy Shevchenko <[email protected]>
> > > ---
> > >
> > ...
> > > +static int litex_mmc_probe(struct platform_device *pdev)
> > > +{
> > > + struct device *dev = &pdev->dev;
> > > + struct litex_mmc_host *host;
> > > + struct mmc_host *mmc;
> > > + struct clk *clk;
> > > + int ret;
> > > +
> > > + /*
> > > + * NOTE: defaults to max_[req,seg]_size=PAGE_SIZE, max_blk_size=512,
> > > + * and max_blk_count accordingly set to 8;
> > > + * If for some reason we need to modify max_blk_count, we must also
> > > + * re-calculate `max_[req,seg]_size = max_blk_size * max_blk_count;`
> > > + */
> > > + mmc = mmc_alloc_host(sizeof(struct litex_mmc_host), dev);
> > > + if (!mmc)
> > > + return -ENOMEM;
> > > +
> > > + ret = devm_add_action_or_reset(dev, litex_mmc_free_host_wrapper, mmc);
> > > + if (ret)
> > > + return dev_err_probe(dev, ret,
> > > + "Can't register mmc_free_host action\n");
> > > +
> > > + host = mmc_priv(mmc);
> > > + host->mmc = mmc;
> > > +
> > > + /* Initialize clock source */
> > > + clk = devm_clk_get(dev, NULL);
> > > + if (IS_ERR(clk))
> > > + return dev_err_probe(dev, PTR_ERR(clk), "can't get clock\n");
> > > + host->ref_clk = clk_get_rate(clk);
> > > + host->sd_clk = 0;
> > > +
> > > + /*
> > > + * LiteSDCard only supports 4-bit bus width; therefore, we MUST inject
> > > + * a SET_BUS_WIDTH (acmd6) before the very first data transfer, earlier
> > > + * than when the mmc subsystem would normally get around to it!
> > > + */
> > > + host->is_bus_width_set = false;
> > > + host->app_cmd = false;
> > > +
> > > + /* LiteSDCard can support 64-bit DMA addressing */
> > > + ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
> > > + if (ret)
> > > + return ret;
> > > +
> > > + host->buf_size = mmc->max_req_size * 2;
> > > + host->buffer = dmam_alloc_coherent(dev, host->buf_size,
> > > + &host->dma, GFP_KERNEL);
> > > + if (host->buffer == NULL)
> > > + return -ENOMEM;
> > > +
> > > + host->sdphy = devm_platform_ioremap_resource_byname(pdev, "phy");
> > > + if (IS_ERR(host->sdphy))
> > > + return PTR_ERR(host->sdphy);
> > > +
> > > + host->sdcore = devm_platform_ioremap_resource_byname(pdev, "core");
> > > + if (IS_ERR(host->sdcore))
> > > + return PTR_ERR(host->sdcore);
> > > +
> > > + host->sdreader = devm_platform_ioremap_resource_byname(pdev, "reader");
> > > + if (IS_ERR(host->sdreader))
> > > + return PTR_ERR(host->sdreader);
> > > +
> > > + host->sdwriter = devm_platform_ioremap_resource_byname(pdev, "writer");
> > > + if (IS_ERR(host->sdwriter))
> > > + return PTR_ERR(host->sdwriter);
> > > +
> > > + /* Ensure DMA bus masters are disabled */
> > > + litex_write8(host->sdreader + LITEX_BLK2MEM_ENA, 0);
> > > + litex_write8(host->sdwriter + LITEX_MEM2BLK_ENA, 0);
> > > +
> > > + init_completion(&host->cmd_done);
> > > + ret = litex_mmc_irq_init(pdev, host);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + /* Allow full generic 2.7-3.6V range; no software tuning available */
> > > + mmc->ocr_avail = LITEX_MMC_OCR;
> > > +
> > > + mmc->ops = &litex_mmc_ops;
> > > +
> > > + /*
> > > + * Set default sd_clk frequency range based on empirical observations
> > > + * of LiteSDCard gateware behavior on typical SDCard media
> > > + */
> > > + mmc->f_min = 12.5e6;
> > > + mmc->f_max = 50e6;
> > > +
> > > + ret = mmc_of_parse(mmc);
> > > + if (ret)
> > > + return ret;
> > > +
> > > + /* Force 4-bit bus_width (only width supported by hardware) */
> > > + mmc->caps &= ~MMC_CAP_8_BIT_DATA;
> > > + mmc->caps |= MMC_CAP_4_BIT_DATA;
> > > +
> > > + /* Set default capabilities */
> > > + mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY |
> > > + MMC_CAP_DRIVER_TYPE_D |
> > > + MMC_CAP_CMD23;
> > > + mmc->caps2 |= MMC_CAP2_NO_WRITE_PROTECT |
> > > + MMC_CAP2_NO_SDIO |
> > > + MMC_CAP2_NO_MMC;
> > > +
> > > + platform_set_drvdata(pdev, host);
> >
> > One more thing here. Or somewhere, should we add:
> >
> > dev_info(dev, "Litex MMC controller initialized");
> >
> > I was having a hard time debugging probing of this and having no printk's made
> > it a bit difficult.
> >
> > Though I was able to get most of the debug statements I needed using:
> >
> > "debug initcall_debug dyndbg=\"file drivers/* +p\" loglevel=8"
> >
> > -Stafford
> >
> > > + return mmc_add_host(mmc);
>
> I'd prefer to declare victory *after* calling mmc_add_host(), so if
> there are no objections I'd prefer to do the following in v12:
>
> ...
> platform_set_drvdata(pdev, host);
>
> - return mmc_add_host(mmc);
> + ret = mmc_add_host(mmc);
> + if (ret)
> + return dev_err_probe(dev, ret, "LiteX MMC probe failed!\n");
> +
> + dev_info(dev, "LiteX MMC controller initialized.\n");
> +
> + return 0;
> }
Yes, that is what I was thinking too.
-Stafford