On Wed, 25 Jun 2025, Jarkko Sakkinen wrote:
> On Thu, Jun 19, 2025 at 10:51:37AM +0800, Qunqin Zhao wrote:
> > Loongson Security Engine supports random number generation, hash,
> > symmetric encryption and asymmetric encryption. Based on these
> > encryption functions, TPM2 have been implemented in the Loongson
> > Security Engine firmware. This driver is responsible for copying data
> > into the memory visible to the firmware and receiving data from the
> > firmware.
> >
> > Co-developed-by: Yinggang Gu <guyingg...@loongson.cn>
> > Signed-off-by: Yinggang Gu <guyingg...@loongson.cn>
> > Signed-off-by: Qunqin Zhao <zhaoqun...@loongson.cn>
> > Reviewed-by: Huacai Chen <chenhua...@loongson.cn>
> > ---
> > drivers/char/tpm/Kconfig | 9 ++++
> > drivers/char/tpm/Makefile | 1 +
> > drivers/char/tpm/tpm_loongson.c | 84 +++++++++++++++++++++++++++++++++
> > 3 files changed, 94 insertions(+)
> > create mode 100644 drivers/char/tpm/tpm_loongson.c
> >
> > diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
> > index dddd702b2..ba3924eb1 100644
> > --- a/drivers/char/tpm/Kconfig
> > +++ b/drivers/char/tpm/Kconfig
> > @@ -189,6 +189,15 @@ config TCG_IBMVTPM
> > will be accessible from within Linux. To compile this driver
> > as a module, choose M here; the module will be called tpm_ibmvtpm.
> >
> > +config TCG_LOONGSON
> > + tristate "Loongson TPM Interface"
> > + depends on MFD_LOONGSON_SE
> > + help
> > + If you want to make Loongson TPM support available, say Yes and
> > + it will be accessible from within Linux. To compile this
> > + driver as a module, choose M here; the module will be called
> > + tpm_loongson.
> > +
> > config TCG_XEN
> > tristate "XEN TPM Interface"
> > depends on TCG_TPM && XEN
> > diff --git a/drivers/char/tpm/Makefile b/drivers/char/tpm/Makefile
> > index 9de1b3ea3..5b5cdc0d3 100644
> > --- a/drivers/char/tpm/Makefile
> > +++ b/drivers/char/tpm/Makefile
> > @@ -46,3 +46,4 @@ obj-$(CONFIG_TCG_ARM_CRB_FFA) += tpm_crb_ffa.o
> > obj-$(CONFIG_TCG_VTPM_PROXY) += tpm_vtpm_proxy.o
> > obj-$(CONFIG_TCG_FTPM_TEE) += tpm_ftpm_tee.o
> > obj-$(CONFIG_TCG_SVSM) += tpm_svsm.o
> > +obj-$(CONFIG_TCG_LOONGSON) += tpm_loongson.o
> > diff --git a/drivers/char/tpm/tpm_loongson.c
> > b/drivers/char/tpm/tpm_loongson.c
> > new file mode 100644
> > index 000000000..5cbdb37f8
> > --- /dev/null
> > +++ b/drivers/char/tpm/tpm_loongson.c
> > @@ -0,0 +1,84 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/* Copyright (c) 2025 Loongson Technology Corporation Limited. */
> > +
> > +#include <linux/device.h>
> > +#include <linux/mfd/loongson-se.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/wait.h>
> > +
> > +#include "tpm.h"
> > +
> > +struct tpm_loongson_cmd {
> > + u32 cmd_id;
> > + u32 data_off;
> > + u32 data_len;
> > + u32 pad[5];
> > +};
> > +
> > +static int tpm_loongson_recv(struct tpm_chip *chip, u8 *buf, size_t count)
> > +{
> > + struct loongson_se_engine *tpm_engine = dev_get_drvdata(&chip->dev);
> > + struct tpm_loongson_cmd *cmd_ret = tpm_engine->command_ret;
> > +
> > + if (cmd_ret->data_len > count)
> > + return -EIO;
> > +
> > + memcpy(buf, tpm_engine->data_buffer, cmd_ret->data_len);
> > +
> > + return cmd_ret->data_len;
> > +}
> > +
> > +static int tpm_loongson_send(struct tpm_chip *chip, u8 *buf, size_t count)
> > +{
> > + struct loongson_se_engine *tpm_engine = dev_get_drvdata(&chip->dev);
> > + struct tpm_loongson_cmd *cmd = tpm_engine->command;
> > +
> > + if (count > tpm_engine->buffer_size)
> > + return -E2BIG;
> > +
> > + cmd->data_len = count;
> > + memcpy(tpm_engine->data_buffer, buf, count);
> > +
> > + return loongson_se_send_engine_cmd(tpm_engine);
> > +}
> > +
> > +static const struct tpm_class_ops tpm_loongson_ops = {
> > + .flags = TPM_OPS_AUTO_STARTUP,
> > + .recv = tpm_loongson_recv,
> > + .send = tpm_loongson_send,
> > +};
> > +
> > +static int tpm_loongson_probe(struct platform_device *pdev)
> > +{
> > + struct loongson_se_engine *tpm_engine;
> > + struct device *dev = &pdev->dev;
> > + struct tpm_loongson_cmd *cmd;
> > + struct tpm_chip *chip;
> > +
> > + tpm_engine = loongson_se_init_engine(dev->parent, SE_ENGINE_TPM);
> > + if (!tpm_engine)
> > + return -ENODEV;
> > + cmd = tpm_engine->command;
> > + cmd->cmd_id = SE_CMD_TPM;
> > + cmd->data_off = tpm_engine->buffer_off;
> > +
> > + chip = tpmm_chip_alloc(dev, &tpm_loongson_ops);
> > + if (IS_ERR(chip))
> > + return PTR_ERR(chip);
> > + chip->flags = TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_IRQ;
> > + dev_set_drvdata(&chip->dev, tpm_engine);
> > +
> > + return tpm_chip_register(chip);
> > +}
> > +
> > +static struct platform_driver tpm_loongson = {
> > + .probe = tpm_loongson_probe,
> > + .driver = {
> > + .name = "loongson-tpm",
>
> This patch looks otherwise great but I'd prefer here tho use
> "tpm_loongson_probe" for the value of the name field.
Where does this stipulation come from? No other driver does this [0].
driver.name should be a nicely formatted, human readable string
describing the name of the device. Not a function name.
[0] git grep -A15 "static struct platform_driver" | grep ".name = .*probe"
--
Lee Jones [李琼斯]
