Commit d5812571 authored by Mario Limonciello's avatar Mario Limonciello Committed by Herbert Xu

crypto: ccp - Add support for ringing a platform doorbell

Some platforms support using a doorbell to communicate. Export
this feature for other drivers to utilize as well.

Link: https://lore.kernel.org/linux-i2c/20220916131854.687371-3-jsd@semihalf.com/Suggested-by: default avatarJan Dabros <jsd@semihalf.com>
Signed-off-by: default avatarMario Limonciello <mario.limonciello@amd.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 22351239
......@@ -20,6 +20,14 @@
#define PSP_CMD_TIMEOUT_US (500 * USEC_PER_MSEC)
/* Doorbell shouldn't be ringing */
static int check_doorbell(u32 __iomem *doorbell)
{
u32 tmp;
return readl_poll_timeout(doorbell, tmp, tmp != 0, 0, PSP_CMD_TIMEOUT_US);
}
/* Recovery field should be equal 0 to start sending commands */
static int check_recovery(u32 __iomem *cmd)
{
......@@ -132,6 +140,62 @@ int psp_send_platform_access_msg(enum psp_platform_access_msg msg,
}
EXPORT_SYMBOL_GPL(psp_send_platform_access_msg);
int psp_ring_platform_doorbell(int msg)
{
struct psp_device *psp = psp_get_master_device();
struct psp_platform_access_device *pa_dev;
u32 __iomem *button, *cmd;
int ret, val;
if (!psp || !psp->platform_access_data)
return -ENODEV;
pa_dev = psp->platform_access_data;
button = psp->io_regs + pa_dev->vdata->doorbell_button_reg;
cmd = psp->io_regs + pa_dev->vdata->doorbell_cmd_reg;
mutex_lock(&pa_dev->doorbell_mutex);
if (check_doorbell(button)) {
dev_dbg(psp->dev, "doorbell is not ready\n");
ret = -EBUSY;
goto unlock;
}
if (check_recovery(cmd)) {
dev_dbg(psp->dev, "doorbell command in recovery\n");
ret = -EBUSY;
goto unlock;
}
if (wait_cmd(cmd)) {
dev_dbg(psp->dev, "doorbell command not done processing\n");
ret = -EBUSY;
goto unlock;
}
iowrite32(FIELD_PREP(PSP_DRBL_MSG, msg), cmd);
iowrite32(PSP_DRBL_RING, button);
if (wait_cmd(cmd)) {
ret = -ETIMEDOUT;
goto unlock;
}
val = FIELD_GET(PSP_CMDRESP_STS, ioread32(cmd));
if (val) {
ret = -EIO;
goto unlock;
}
ret = 0;
unlock:
mutex_unlock(&pa_dev->doorbell_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(psp_ring_platform_doorbell);
void platform_access_dev_destroy(struct psp_device *psp)
{
struct psp_platform_access_device *pa_dev = psp->platform_access_data;
......@@ -140,6 +204,7 @@ void platform_access_dev_destroy(struct psp_device *psp)
return;
mutex_destroy(&pa_dev->mailbox_mutex);
mutex_destroy(&pa_dev->doorbell_mutex);
psp->platform_access_data = NULL;
}
......@@ -159,6 +224,7 @@ int platform_access_dev_init(struct psp_device *psp)
pa_dev->vdata = (struct platform_access_vdata *)psp->vdata->platform_access;
mutex_init(&pa_dev->mailbox_mutex);
mutex_init(&pa_dev->doorbell_mutex);
dev_dbg(dev, "platform access enabled\n");
......
......@@ -24,6 +24,7 @@ struct psp_platform_access_device {
struct platform_access_vdata *vdata;
struct mutex mailbox_mutex;
struct mutex doorbell_mutex;
void *platform_access_data;
};
......
......@@ -57,6 +57,9 @@ struct platform_access_vdata {
const unsigned int cmdresp_reg;
const unsigned int cmdbuff_addr_lo_reg;
const unsigned int cmdbuff_addr_hi_reg;
const unsigned int doorbell_button_reg;
const unsigned int doorbell_cmd_reg;
};
struct psp_vdata {
......
......@@ -365,6 +365,8 @@ static const struct platform_access_vdata pa_v1 = {
.cmdresp_reg = 0x10570, /* C2PMSG_28 */
.cmdbuff_addr_lo_reg = 0x10574, /* C2PMSG_29 */
.cmdbuff_addr_hi_reg = 0x10578, /* C2PMSG_30 */
.doorbell_button_reg = 0x10a24, /* C2PMSG_73 */
.doorbell_cmd_reg = 0x10a40, /* C2PMSG_80 */
};
static const struct psp_vdata pspv1 = {
......
......@@ -34,6 +34,21 @@ struct psp_request {
*/
int psp_send_platform_access_msg(enum psp_platform_access_msg, struct psp_request *req);
/**
* psp_ring_platform_doorbell() - Ring platform doorbell
*
* This function is intended to be used by drivers outside of ccp to ring the
* platform doorbell with a message.
*
* Returns:
* 0: success
* -%EBUSY: mailbox in recovery or in use
* -%ENODEV: driver not bound with PSP device
* -%ETIMEDOUT: request timed out
* -%EIO: unknown error (see kernel log)
*/
int psp_ring_platform_doorbell(int msg);
/**
* psp_check_platform_access_status() - Checks whether platform features is ready
*
......
......@@ -23,4 +23,7 @@
#define PSP_CMDRESP_RECOVERY BIT(30)
#define PSP_CMDRESP_RESP BIT(31)
#define PSP_DRBL_MSG PSP_CMDRESP_CMD
#define PSP_DRBL_RING BIT(0)
#endif /* __PSP_H */
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