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i2c: designware: Add doorbell support for Mendocino

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Mendocino and later platform don't use the platform feature mailbox for
communication for I2C arbitration, they rely upon ringing a doorbell.

Detect the platform by the device ID of the root port and choose the
appropriate method.

Link: https://lore.kernel.org/linux-i2c/20220916131854.687371-3-jsd@semihalf.com/
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Mark Hasemeyer <markhas@chromium.org>
Tested-by: Mark Hasemeyer <markhas@chromium.org>
Acked-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Mario Limonciello 2023-04-14 09:40:08 -05:00 committed by Herbert Xu
parent 440da737cf
commit 482c84e906
2 changed files with 26 additions and 1 deletions
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1
drivers/i2c/busses/Kconfig
View File

@ -568,6 +568,7 @@ config I2C_DESIGNWARE_AMDPSP
bool "AMD PSP I2C semaphore support"
depends on ACPI
depends on CRYPTO_DEV_SP_PSP
depends on PCI
depends on I2C_DESIGNWARE_PLATFORM
depends on (I2C_DESIGNWARE_PLATFORM=y && CRYPTO_DEV_CCP_DD=y) || \
(I2C_DESIGNWARE_PLATFORM=m && CRYPTO_DEV_CCP_DD)

26
drivers/i2c/busses/i2c-designware-amdpsp.c
View File

@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/i2c.h>
#include <linux/pci.h>
#include <linux/psp-platform-access.h>
#include <linux/psp.h>
#include <linux/workqueue.h>
@ -32,6 +33,8 @@ static u32 psp_i2c_access_count;
static bool psp_i2c_mbox_fail;
static struct device *psp_i2c_dev;
static int (*_psp_send_i2c_req)(struct psp_i2c_req *req);
/* Helper to verify status returned by PSP */
static int check_i2c_req_sts(struct psp_i2c_req *req)
{
@ -72,6 +75,17 @@ static int psp_send_i2c_req_cezanne(struct psp_i2c_req *req)
return ret;
}
static int psp_send_i2c_req_doorbell(struct psp_i2c_req *req)
{
int ret;
ret = psp_ring_platform_doorbell(req->type, &req->hdr.status);
if (ret == -EIO)
return check_i2c_req_sts(req);
return ret;
}
static int psp_send_i2c_req(enum psp_i2c_req_type i2c_req_type)
{
struct psp_i2c_req *req;
@ -87,7 +101,7 @@ static int psp_send_i2c_req(enum psp_i2c_req_type i2c_req_type)
req->type = i2c_req_type;
start = jiffies;
ret = read_poll_timeout(psp_send_i2c_req_cezanne, status,
ret = read_poll_timeout(_psp_send_i2c_req, status,
(status != -EBUSY),
PSP_I2C_REQ_RETRY_DELAY_US,
PSP_I2C_REQ_RETRY_CNT * PSP_I2C_REQ_RETRY_DELAY_US,
@ -262,6 +276,8 @@ static const struct i2c_lock_operations i2c_dw_psp_lock_ops = {
int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev)
{
struct pci_dev *rdev;
if (!IS_REACHABLE(CONFIG_CRYPTO_DEV_CCP_DD))
return -ENODEV;
@ -275,6 +291,14 @@ int i2c_dw_amdpsp_probe_lock_support(struct dw_i2c_dev *dev)
if (psp_i2c_dev)
return -EEXIST;
/* Cezanne uses platform mailbox, Mendocino and later use doorbell */
rdev = pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(0, 0));
if (rdev->device == 0x1630)
_psp_send_i2c_req = psp_send_i2c_req_cezanne;
else
_psp_send_i2c_req = psp_send_i2c_req_doorbell;
pci_dev_put(rdev);
if (psp_check_platform_access_status())
return -EPROBE_DEFER;