[V7,2/3] tpm_tis-spi: Add hardware wait polling
Commit Message
TPM devices may insert wait state on last clock cycle of ADDR phase.
For SPI controllers that support full-duplex transfers, this can be
detected using software by reading the MISO line. For SPI controllers
that only support half-duplex transfers, such as the Tegra QSPI, it is
not possible to detect the wait signal from software. The QSPI
controller in Tegra234 and Tegra241 implement hardware detection of the
wait signal which can be enabled in the controller for TPM devices.
The current TPM TIS driver only supports software detection of the wait
signal. To support SPI controllers that use hardware to detect the wait
signal, add the function tpm_tis_spi_hw_flow_transfer() and move the
existing code for software based detection into a function called
tpm_tis_spi_sw_flow_transfer(). SPI controllers that only support
half-duplex transfers will always call tpm_tis_spi_hw_flow_transfer()
because they cannot support software based detection. The bit
SPI_TPM_HW_FLOW is set to indicate to the SPI controller that hardware
detection is required and it is the responsibility of the SPI controller
driver to determine if this is supported or not.
For hardware flow control, CMD-ADDR-DATA messages are combined into a
single message where as for software flow control exiting method of
CMD-ADDR in a message and DATA in another is followed.
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
drivers/char/tpm/tpm_tis_spi_main.c | 96 ++++++++++++++++++++++++++++-
1 file changed, 94 insertions(+), 2 deletions(-)
Comments
Hi Krishna,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on broonie-spi/for-next]
[also build test WARNING on char-misc/char-misc-testing char-misc/char-misc-next char-misc/char-misc-linus linus/master v6.2 next-20230301]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Krishna-Yarlagadda/spi-Add-TPM-HW-flow-flag/20230302-013628
base: https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next
patch link: https://lore.kernel.org/r/20230301173353.28673-3-kyarlagadda%40nvidia.com
patch subject: [Patch V7 2/3] tpm_tis-spi: Add hardware wait polling
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230302/202303020622.v3NqL5mg-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/d47344c6b9ab634483742457f6692b01f02c4698
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Krishna-Yarlagadda/spi-Add-TPM-HW-flow-flag/20230302-013628
git checkout d47344c6b9ab634483742457f6692b01f02c4698
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/char/tpm/
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303020622.v3NqL5mg-lkp@intel.com/
All warnings (new ones prefixed by >>):
drivers/char/tpm/tpm_tis_spi_main.c:335:36: warning: 'acpi_tis_spi_match' defined but not used [-Wunused-const-variable=]
335 | static const struct acpi_device_id acpi_tis_spi_match[] = {
| ^~~~~~~~~~~~~~~~~~
drivers/char/tpm/tpm_tis_spi_main.c: In function 'tpm_tis_spi_probe':
>> drivers/char/tpm/tpm_tis_spi_main.c:263:42: warning: 'phy' is used uninitialized [-Wuninitialized]
263 | struct spi_controller *ctlr = phy->spi_device->controller;
| ~~~^~~~~~~~~~~~
drivers/char/tpm/tpm_tis_spi_main.c:262:33: note: 'phy' was declared here
262 | struct tpm_tis_spi_phy *phy;
| ^~~
vim +/phy +263 drivers/char/tpm/tpm_tis_spi_main.c
259
260 static int tpm_tis_spi_probe(struct spi_device *dev)
261 {
262 struct tpm_tis_spi_phy *phy;
> 263 struct spi_controller *ctlr = phy->spi_device->controller;
264 int irq;
265
266 phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
267 GFP_KERNEL);
268 if (!phy)
269 return -ENOMEM;
270
271 phy->flow_control = tpm_tis_spi_flow_control;
272
273 if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
274 phy->spi_device->mode |= SPI_TPM_HW_FLOW;
275
276 /* If the SPI device has an IRQ then use that */
277 if (dev->irq > 0)
278 irq = dev->irq;
279 else
280 irq = -1;
281
282 init_completion(&phy->ready);
283 return tpm_tis_spi_init(dev, phy, irq, &tpm_spi_phy_ops);
284 }
285
@@ -71,8 +71,76 @@ static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy,
return 0;
}
-int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
- u8 *in, const u8 *out)
+/*
+ * Half duplex controller with support for TPM wait state detection like
+ * Tegra QSPI need CMD, ADDR & DATA sent in single message to manage HW flow
+ * control. Each phase sent in different transfer for controller to idenity
+ * phase.
+ */
+static int tpm_tis_spi_hw_flow_transfer(struct tpm_tis_data *data,
+ u32 addr, u16 len, u8 *in,
+ const u8 *out)
+{
+ struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
+ struct spi_transfer spi_xfer[3];
+ struct spi_message m;
+ u8 transfer_len;
+ int ret;
+
+ while (len) {
+ transfer_len = min_t(u16, len, MAX_SPI_FRAMESIZE);
+
+ spi_message_init(&m);
+ phy->iobuf[0] = (in ? 0x80 : 0) | (transfer_len - 1);
+ phy->iobuf[1] = 0xd4;
+ phy->iobuf[2] = addr >> 8;
+ phy->iobuf[3] = addr;
+
+ memset(&spi_xfer, 0, sizeof(spi_xfer));
+
+ spi_xfer[0].tx_buf = phy->iobuf;
+ spi_xfer[0].len = 1;
+ spi_message_add_tail(&spi_xfer[0], &m);
+
+ spi_xfer[1].tx_buf = phy->iobuf + 1;
+ spi_xfer[1].len = 3;
+ spi_message_add_tail(&spi_xfer[1], &m);
+
+ if (out) {
+ spi_xfer[2].tx_buf = &phy->iobuf[4];
+ spi_xfer[2].rx_buf = NULL;
+ memcpy(&phy->iobuf[4], out, transfer_len);
+ out += transfer_len;
+ }
+
+ if (in) {
+ spi_xfer[2].tx_buf = NULL;
+ spi_xfer[2].rx_buf = &phy->iobuf[4];
+ }
+
+ spi_xfer[2].len = transfer_len;
+ spi_message_add_tail(&spi_xfer[2], &m);
+
+ reinit_completion(&phy->ready);
+
+ ret = spi_sync_locked(phy->spi_device, &m);
+ if (ret < 0)
+ return ret;
+
+ if (in) {
+ memcpy(in, &phy->iobuf[4], transfer_len);
+ in += transfer_len;
+ }
+
+ len -= transfer_len;
+ }
+
+ return ret;
+}
+
+static int tpm_tis_spi_sw_flow_transfer(struct tpm_tis_data *data,
+ u32 addr, u16 len, u8 *in,
+ const u8 *out)
{
struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
int ret = 0;
@@ -140,6 +208,26 @@ int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
return ret;
}
+int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len,
+ u8 *in, const u8 *out)
+{
+ struct tpm_tis_spi_phy *phy = to_tpm_tis_spi_phy(data);
+ struct spi_controller *ctlr = phy->spi_device->controller;
+
+ /*
+ * TPM flow control over SPI requires full duplex support.
+ * Send entire message to a half duplex controller to handle
+ * wait polling in controller.
+ * Set TPM HW flow control flag..
+ */
+ if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
+ return tpm_tis_spi_hw_flow_transfer(data, addr, len, in,
+ out);
+ else
+ return tpm_tis_spi_sw_flow_transfer(data, addr, len, in,
+ out);
+}
+
static int tpm_tis_spi_read_bytes(struct tpm_tis_data *data, u32 addr,
u16 len, u8 *result, enum tpm_tis_io_mode io_mode)
{
@@ -172,6 +260,7 @@ static const struct tpm_tis_phy_ops tpm_spi_phy_ops = {
static int tpm_tis_spi_probe(struct spi_device *dev)
{
struct tpm_tis_spi_phy *phy;
+ struct spi_controller *ctlr = phy->spi_device->controller;
int irq;
phy = devm_kzalloc(&dev->dev, sizeof(struct tpm_tis_spi_phy),
@@ -181,6 +270,9 @@ static int tpm_tis_spi_probe(struct spi_device *dev)
phy->flow_control = tpm_tis_spi_flow_control;
+ if (ctlr->flags & SPI_CONTROLLER_HALF_DUPLEX)
+ phy->spi_device->mode |= SPI_TPM_HW_FLOW;
+
/* If the SPI device has an IRQ then use that */
if (dev->irq > 0)
irq = dev->irq;