From: Dragos Rosioru <dragos.rosioru@xxxxxxx>
Added suspend/resume operations for PM support in the DCP driver.
After a suspend/resume cycle DCP would still be in a low-power mode
and have its clocks gated, thus requiring state to be saved beforehand:
- Control register value(DCP_CTRL)
- Channel control register value(DCP_CHANNELCTRL)
Signed-off-by: Dragos Rosioru <dragos.rosioru@xxxxxxx>
---
drivers/crypto/mxs-dcp.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 74 insertions(+), 2 deletions(-)
diff --git a/drivers/crypto/mxs-dcp.c b/drivers/crypto/mxs-dcp.c
index d6a7784..6748a4a 100644
--- a/drivers/crypto/mxs-dcp.c
+++ b/drivers/crypto/mxs-dcp.c
@@ -23,6 +23,10 @@
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
+#ifdef CONFIG_PM_SLEEP
+#include <linux/freezer.h>
+#endif
+
#define DCP_MAX_CHANS 4
#define DCP_BUF_SZ PAGE_SIZE
#define DCP_SHA_PAY_SZ 64
@@ -124,7 +128,10 @@ struct dcp_export_state {
* design of Linux Crypto API.
*/
static struct dcp *global_sdcp;
-
+#ifdef CONFIG_PM_SLEEP
+static uint32_t ctrl_bak;
+static int dcp_vmi_irq_bak, dcp_irq_bak;
+#endif
/* DCP register layout. */
#define MXS_DCP_CTRL 0x00
#define MXS_DCP_CTRL_GATHER_RESIDUAL_WRITES (1 << 23)
@@ -398,9 +405,15 @@ static int dcp_chan_thread_aes(void *data)
int ret;
+#ifdef CONFIG_PM_SLEEP
+ set_freezable();
+#endif
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
+#ifdef CONFIG_PM_SLEEP
+ try_to_freeze();
+#endif
spin_lock(&sdcp->lock[chan]);
backlog = crypto_get_backlog(&sdcp->queue[chan]);
arq = crypto_dequeue_request(&sdcp->queue[chan]);
@@ -438,6 +451,10 @@ static int mxs_dcp_block_fallback(struct skcipher_request *req, int enc)
skcipher_request_set_crypt(&rctx->fallback_req, req->src, req->dst,
req->cryptlen, req->iv);
+#ifdef CONFIG_PM_SLEEP
+ set_freezable();
+ try_to_freeze();
+#endif
if (enc)
ret = crypto_skcipher_encrypt(&rctx->fallback_req);
else
@@ -686,9 +703,15 @@ static int dcp_chan_thread_sha(void *data)
struct crypto_async_request *arq;
int ret;
+#ifdef CONFIG_PM_SLEEP
+ set_freezable();
+#endif
while (!kthread_should_stop()) {
set_current_state(TASK_INTERRUPTIBLE);
+#ifdef CONFIG_PM_SLEEP
+ try_to_freeze();
+#endif
spin_lock(&sdcp->lock[chan]);
backlog = crypto_get_backlog(&sdcp->queue[chan]);
arq = crypto_dequeue_request(&sdcp->queue[chan]);
@@ -961,6 +984,49 @@ static irqreturn_t mxs_dcp_irq(int irq, void *context)
return IRQ_HANDLED;
}
+#ifdef CONFIG_PM_SLEEP
+static int mxs_dcp_resume(struct device *dev)
+{
+ struct dcp *sdcp = global_sdcp;
+ int ret;
+
+ /* Restart the DCP block */
+ ret = stmp_reset_block(sdcp->base);
+ if (ret) {
+ dev_err(dev, "Failed reset\n");
+ clk_disable_unprepare(sdcp->dcp_clk);
+ return ret;
+ }
+
+ /* Restore control register */
+ writel(ctrl_bak, sdcp->base + MXS_DCP_CTRL);
+ /* Enable all DCP DMA channels */
+ writel(MXS_DCP_CHANNELCTRL_ENABLE_CHANNEL_MASK,
+ sdcp->base + MXS_DCP_CHANNELCTRL);
+
+ /* Re-enable DCP interrupts */
+ enable_irq(dcp_irq_bak);
+ enable_irq(dcp_vmi_irq_bak);
+
+ return 0;
+}
+
+static int mxs_dcp_suspend(struct device *dev)
+{
+ struct dcp *sdcp = global_sdcp;
+
+ /* Backup control register */
+ ctrl_bak = readl(sdcp->base + MXS_DCP_CTRL);
+ /* Temporarily disable DCP interrupts */
+ disable_irq(dcp_irq_bak);
+ disable_irq(dcp_vmi_irq_bak);
+
+ return 0;
+}
+
+SIMPLE_DEV_PM_OPS(mxs_dcp_pm_ops, mxs_dcp_suspend, mxs_dcp_resume);
+#endif
+
static int mxs_dcp_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -980,7 +1046,10 @@ static int mxs_dcp_probe(struct platform_device *pdev)
dcp_irq = platform_get_irq(pdev, 1);
if (dcp_irq < 0)
return dcp_irq;
-
+#ifdef CONFIG_PM_SLEEP
+ dcp_vmi_irq_bak = dcp_vmi_irq;
+ dcp_irq_bak = dcp_irq;
+#endif
sdcp = devm_kzalloc(dev, sizeof(*sdcp), GFP_KERNEL);
if (!sdcp)
return -ENOMEM;
@@ -1172,6 +1241,9 @@ static struct platform_driver mxs_dcp_driver = {
.driver = {
.name = "mxs-dcp",
.of_match_table = mxs_dcp_dt_ids,
+#ifdef CONFIG_PM_SLEEP
+ .pm = &mxs_dcp_pm_ops
+#endif
},
};
--
2.7.4
