diff options
Diffstat (limited to 'drivers/char/tpm/tpm_tis_spi.c')
| -rw-r--r-- | drivers/char/tpm/tpm_tis_spi.c | 143 |
1 files changed, 87 insertions, 56 deletions
diff --git a/drivers/char/tpm/tpm_tis_spi.c b/drivers/char/tpm/tpm_tis_spi.c index 19513e622053..d1754fd6c573 100644 --- a/drivers/char/tpm/tpm_tis_spi.c +++ b/drivers/char/tpm/tpm_tis_spi.c @@ -20,42 +20,64 @@ * Dorn and Kyleen Hall and Jarko Sakkinnen. */ +#include <linux/acpi.h> +#include <linux/completion.h> #include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/kernel.h> #include <linux/module.h> -#include <linux/moduleparam.h> #include <linux/slab.h> -#include <linux/interrupt.h> -#include <linux/wait.h> -#include <linux/acpi.h> -#include <linux/freezer.h> +#include <linux/of_device.h> #include <linux/spi/spi.h> -#include <linux/gpio.h> -#include <linux/of_irq.h> -#include <linux/of_gpio.h> #include <linux/tpm.h> + #include "tpm.h" #include "tpm_tis_core.h" +#include "tpm_tis_spi.h" #define MAX_SPI_FRAMESIZE 64 -struct tpm_tis_spi_phy { - struct tpm_tis_data priv; - struct spi_device *spi_device; - u8 *iobuf; -}; - -static inline struct tpm_tis_spi_phy *to_tpm_tis_spi_phy(struct tpm_tis_data *data) +/* + * TCG SPI flow control is documented in section 6.4 of the spec[1]. In short, + * keep trying to read from the device until MISO goes high indicating the + * wait state has ended. + * + * [1] https://trustedcomputinggroup.org/resource/pc-client-platform-tpm-profile-ptp-specification/ + */ +static int tpm_tis_spi_flow_control(struct tpm_tis_spi_phy *phy, + struct spi_transfer *spi_xfer) { - return container_of(data, struct tpm_tis_spi_phy, priv); + struct spi_message m; + int ret, i; + + if ((phy->iobuf[3] & 0x01) == 0) { + // handle SPI wait states + phy->iobuf[0] = 0; + + for (i = 0; i < TPM_RETRY; i++) { + spi_xfer->len = 1; + spi_message_init(&m); + spi_message_add_tail(spi_xfer, &m); + ret = spi_sync_locked(phy->spi_device, &m); + if (ret < 0) + return ret; + if (phy->iobuf[0] & 0x01) + break; + } + + if (i == TPM_RETRY) + return -ETIMEDOUT; + } + + return 0; } -static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, - u8 *in, const u8 *out) +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); int ret = 0; - int i; struct spi_message m; struct spi_transfer spi_xfer; u8 transfer_len; @@ -82,26 +104,9 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, if (ret < 0) goto exit; - if ((phy->iobuf[3] & 0x01) == 0) { - // handle SPI wait states - phy->iobuf[0] = 0; - - for (i = 0; i < TPM_RETRY; i++) { - spi_xfer.len = 1; - spi_message_init(&m); - spi_message_add_tail(&spi_xfer, &m); - ret = spi_sync_locked(phy->spi_device, &m); - if (ret < 0) - goto exit; - if (phy->iobuf[0] & 0x01) - break; - } - - if (i == TPM_RETRY) { - ret = -ETIMEDOUT; - goto exit; - } - } + ret = phy->flow_control(phy, &spi_xfer); + if (ret < 0) + goto exit; spi_xfer.cs_change = 0; spi_xfer.len = transfer_len; @@ -117,6 +122,7 @@ static int tpm_tis_spi_transfer(struct tpm_tis_data *data, u32 addr, u16 len, spi_message_init(&m); spi_message_add_tail(&spi_xfer, &m); + reinit_completion(&phy->ready); ret = spi_sync_locked(phy->spi_device, &m); if (ret < 0) goto exit; @@ -146,7 +152,7 @@ static int tpm_tis_spi_write_bytes(struct tpm_tis_data *data, u32 addr, return tpm_tis_spi_transfer(data, addr, len, NULL, value); } -static int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result) +int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result) { __le16 result_le; int rc; @@ -159,7 +165,7 @@ static int tpm_tis_spi_read16(struct tpm_tis_data *data, u32 addr, u16 *result) return rc; } -static int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result) +int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result) { __le32 result_le; int rc; @@ -172,7 +178,7 @@ static int tpm_tis_spi_read32(struct tpm_tis_data *data, u32 addr, u32 *result) return rc; } -static int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value) +int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value) { __le32 value_le; int rc; @@ -184,6 +190,18 @@ static int tpm_tis_spi_write32(struct tpm_tis_data *data, u32 addr, u32 value) return rc; } +int tpm_tis_spi_init(struct spi_device *spi, struct tpm_tis_spi_phy *phy, + int irq, const struct tpm_tis_phy_ops *phy_ops) +{ + phy->iobuf = devm_kmalloc(&spi->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL); + if (!phy->iobuf) + return -ENOMEM; + + phy->spi_device = spi; + + return tpm_tis_core_init(&spi->dev, &phy->priv, irq, phy_ops, NULL); +} + static const struct tpm_tis_phy_ops tpm_spi_phy_ops = { .read_bytes = tpm_tis_spi_read_bytes, .write_bytes = tpm_tis_spi_write_bytes, @@ -202,11 +220,7 @@ static int tpm_tis_spi_probe(struct spi_device *dev) if (!phy) return -ENOMEM; - phy->spi_device = dev; - - phy->iobuf = devm_kmalloc(&dev->dev, MAX_SPI_FRAMESIZE, GFP_KERNEL); - if (!phy->iobuf) - return -ENOMEM; + phy->flow_control = tpm_tis_spi_flow_control; /* If the SPI device has an IRQ then use that */ if (dev->irq > 0) @@ -214,11 +228,27 @@ static int tpm_tis_spi_probe(struct spi_device *dev) else irq = -1; - return tpm_tis_core_init(&dev->dev, &phy->priv, irq, &tpm_spi_phy_ops, - NULL); + init_completion(&phy->ready); + return tpm_tis_spi_init(dev, phy, irq, &tpm_spi_phy_ops); +} + +typedef int (*tpm_tis_spi_probe_func)(struct spi_device *); + +static int tpm_tis_spi_driver_probe(struct spi_device *spi) +{ + const struct spi_device_id *spi_dev_id = spi_get_device_id(spi); + tpm_tis_spi_probe_func probe_func; + + probe_func = of_device_get_match_data(&spi->dev); + if (!probe_func && spi_dev_id) + probe_func = (tpm_tis_spi_probe_func)spi_dev_id->driver_data; + if (!probe_func) + return -ENODEV; + + return probe_func(spi); } -static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_resume); +static SIMPLE_DEV_PM_OPS(tpm_tis_pm, tpm_pm_suspend, tpm_tis_spi_resume); static int tpm_tis_spi_remove(struct spi_device *dev) { @@ -230,15 +260,17 @@ static int tpm_tis_spi_remove(struct spi_device *dev) } static const struct spi_device_id tpm_tis_spi_id[] = { - {"tpm_tis_spi", 0}, + { "tpm_tis_spi", (unsigned long)tpm_tis_spi_probe }, + { "cr50", (unsigned long)cr50_spi_probe }, {} }; MODULE_DEVICE_TABLE(spi, tpm_tis_spi_id); static const struct of_device_id of_tis_spi_match[] = { - { .compatible = "st,st33htpm-spi", }, - { .compatible = "infineon,slb9670", }, - { .compatible = "tcg,tpm_tis-spi", }, + { .compatible = "st,st33htpm-spi", .data = tpm_tis_spi_probe }, + { .compatible = "infineon,slb9670", .data = tpm_tis_spi_probe }, + { .compatible = "tcg,tpm_tis-spi", .data = tpm_tis_spi_probe }, + { .compatible = "google,cr50", .data = cr50_spi_probe }, {} }; MODULE_DEVICE_TABLE(of, of_tis_spi_match); @@ -251,13 +283,12 @@ MODULE_DEVICE_TABLE(acpi, acpi_tis_spi_match); static struct spi_driver tpm_tis_spi_driver = { .driver = { - .owner = THIS_MODULE, .name = "tpm_tis_spi", .pm = &tpm_tis_pm, .of_match_table = of_match_ptr(of_tis_spi_match), .acpi_match_table = ACPI_PTR(acpi_tis_spi_match), }, - .probe = tpm_tis_spi_probe, + .probe = tpm_tis_spi_driver_probe, .remove = tpm_tis_spi_remove, .id_table = tpm_tis_spi_id, }; |