The USB3.0 peripheral controller on R-Car SoCs has a dedicated DMAC.
The DMAC needs a "PRD table" in system memory and the DMAC can have
four PRD tables. This patch adds support for the DMAC.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
drivers/usb/gadget/udc/renesas_usb3.c | 393 ++++++++++++++++++++++++++++++++++
1 file changed, 393 insertions(+)
diff --git a/drivers/usb/gadget/udc/renesas_usb3.c b/drivers/usb/gadget/udc/renesas_usb3.c
index cd4c885..389051e 100644
--- a/drivers/usb/gadget/udc/renesas_usb3.c
+++ b/drivers/usb/gadget/udc/renesas_usb3.c
@@ -9,6 +9,7 @@
*/
#include <linux/delay.h>
+#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/extcon.h>
#include <linux/interrupt.h>
@@ -27,6 +28,8 @@
#define USB3_AXI_INT_ENA 0x00c
#define USB3_DMA_INT_STA 0x010
#define USB3_DMA_INT_ENA 0x014
+#define USB3_DMA_CH0_CON(n) (0x030 + ((n) - 1) * 0x10) /* n = 1 to 4 */
+#define USB3_DMA_CH0_PRD_ADR(n) (0x034 + ((n) - 1) * 0x10) /* n = 1 to 4 */
#define USB3_USB_COM_CON 0x200
#define USB3_USB20_CON 0x204
#define USB3_USB30_CON 0x208
@@ -64,6 +67,22 @@
/* AXI_INT_ENA and AXI_INT_STA */
#define AXI_INT_DMAINT BIT(31)
#define AXI_INT_EPCINT BIT(30)
+/* PRD's n = from 1 to 4 */
+#define AXI_INT_PRDEN_CLR_STA_SHIFT(n) (16 + (n) - 1)
+#define AXI_INT_PRDERR_STA_SHIFT(n) (0 + (n) - 1)
+#define AXI_INT_PRDEN_CLR_STA(n) (1 << AXI_INT_PRDEN_CLR_STA_SHIFT(n))
+#define AXI_INT_PRDERR_STA(n) (1 << AXI_INT_PRDERR_STA_SHIFT(n))
+
+/* DMA_INT_ENA and DMA_INT_STA */
+#define DMA_INT(n) BIT(n)
+
+/* DMA_CH0_CONn */
+#define DMA_CON_PIPE_DIR BIT(15) /* 1: In Transfer */
+#define DMA_CON_PIPE_NO_SHIFT 8
+#define DMA_CON_PIPE_NO_MASK GENMASK(12, DMA_CON_PIPE_NO_SHIFT)
+#define DMA_COM_PIPE_NO(n) (((n) << DMA_CON_PIPE_NO_SHIFT) & \
+ DMA_CON_PIPE_NO_MASK)
+#define DMA_CON_PRD_EN BIT(0)
/* LCLKSEL */
#define LCLKSEL_LSEL BIT(18)
@@ -231,8 +250,50 @@
#define USB3_EP0_BUF_SIZE 8
#define USB3_MAX_NUM_PIPES 30
#define USB3_WAIT_US 3
+#define USB3_DMA_NUM_SETTING_AREA 4
+/*
+ * To avoid double-meaning of "0" (xferred 65536 bytes or received zlp if
+ * buffer size is 65536), this driver uses the maximum size per a entry is
+ * 32768 bytes.
+ */
+#define USB3_DMA_MAX_XFER_SIZE 32768
+#define USB3_DMA_PRD_SIZE 4096
struct renesas_usb3;
+
+/* Physical Region Descriptor Table */
+struct renesas_usb3_prd {
+ u32 word1;
+#define USB3_PRD1_E BIT(30) /* the end of chain */
+#define USB3_PRD1_U BIT(29) /* completion of transfer */
+#define USB3_PRD1_D BIT(28) /* Error occurred */
+#define USB3_PRD1_INT BIT(27) /* Interrupt occurred */
+#define USB3_PRD1_LST BIT(26) /* Last Packet */
+#define USB3_PRD1_B_INC BIT(24)
+#define USB3_PRD1_MPS_8 0
+#define USB3_PRD1_MPS_16 BIT(21)
+#define USB3_PRD1_MPS_32 BIT(22)
+#define USB3_PRD1_MPS_64 (BIT(22) | BIT(21))
+#define USB3_PRD1_MPS_512 BIT(23)
+#define USB3_PRD1_MPS_1024 (BIT(23) | BIT(21))
+#define USB3_PRD1_MPS_RESERVED (BIT(23) | BIT(22) | BIT(21))
+#define USB3_PRD1_SIZE_MASK GENMASK(15, 0)
+
+ u32 bap;
+};
+#define USB3_DMA_NUM_PRD_ENTRIES (USB3_DMA_PRD_SIZE / \
+ sizeof(struct renesas_usb3_prd))
+#define USB3_DMA_MAX_XFER_SIZE_ALL_PRDS (USB3_DMA_PRD_SIZE / \
+ sizeof(struct renesas_usb3_prd) * \
+ USB3_DMA_MAX_XFER_SIZE)
+
+struct renesas_usb3_dma {
+ struct renesas_usb3_prd *prd;
+ dma_addr_t prd_dma;
+ int num; /* Setting area number (from 1 to 4) */
+ bool used;
+};
+
struct renesas_usb3_request {
struct usb_request req;
struct list_head queue;
@@ -242,6 +303,7 @@ struct renesas_usb3_request {
struct renesas_usb3_ep {
struct usb_ep ep;
struct renesas_usb3 *usb3;
+ struct renesas_usb3_dma *dma;
int num;
char ep_name[USB3_EP_NAME_SIZE];
struct list_head queue;
@@ -270,6 +332,8 @@ struct renesas_usb3 {
struct renesas_usb3_ep *usb3_ep;
int num_usb3_eps;
+ struct renesas_usb3_dma dma[USB3_DMA_NUM_SETTING_AREA];
+
spinlock_t lock;
int disabled_count;
@@ -298,8 +362,18 @@ struct renesas_usb3 {
(i) < (usb3)->num_usb3_eps; \
(i)++, usb3_ep = usb3_get_ep(usb3, (i)))
+#define usb3_get_dma(usb3, i) (&(usb3)->dma[i])
+#define usb3_for_each_dma(usb3, dma, i) \
+ for ((i) = 0, dma = usb3_get_dma((usb3), (i)); \
+ (i) < USB3_DMA_NUM_SETTING_AREA; \
+ (i)++, dma = usb3_get_dma((usb3), (i)))
+
static const char udc_name[] = "renesas_usb3";
+static bool use_dma = 1;
+module_param(use_dma, bool, 0644);
+MODULE_PARM_DESC(use_dma, "use dedicated DMAC");
+
static void usb3_write(struct renesas_usb3 *usb3, u32 data, u32 offs)
{
iowrite32(data, usb3->reg + offs);
@@ -1059,6 +1133,273 @@ static void usb3_start_pipe0(struct renesas_usb3_ep *usb3_ep,
usb3_p0_xfer(usb3_ep, usb3_req);
}
+static void usb3_enable_dma_pipen(struct renesas_usb3 *usb3)
+{
+ usb3_set_bit(usb3, PN_CON_DATAIF_EN, USB3_PN_CON);
+}
+
+static void usb3_disable_dma_pipen(struct renesas_usb3 *usb3)
+{
+ usb3_clear_bit(usb3, PN_CON_DATAIF_EN, USB3_PN_CON);
+}
+
+static void usb3_enable_dma_irq(struct renesas_usb3 *usb3, int num)
+{
+ usb3_set_bit(usb3, DMA_INT(num), USB3_DMA_INT_ENA);
+}
+
+static void usb3_disable_dma_irq(struct renesas_usb3 *usb3, int num)
+{
+ usb3_clear_bit(usb3, DMA_INT(num), USB3_DMA_INT_ENA);
+}
+
+static u32 usb3_dma_mps_to_prd_word1(struct renesas_usb3_ep *usb3_ep)
+{
+ switch (usb3_ep->ep.maxpacket) {
+ case 8:
+ return USB3_PRD1_MPS_8;
+ case 16:
+ return USB3_PRD1_MPS_16;
+ case 32:
+ return USB3_PRD1_MPS_32;
+ case 64:
+ return USB3_PRD1_MPS_64;
+ case 512:
+ return USB3_PRD1_MPS_512;
+ case 1024:
+ return USB3_PRD1_MPS_1024;
+ default:
+ return USB3_PRD1_MPS_RESERVED;
+ }
+}
+
+static bool usb3_dma_get_setting_area(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req)
+{
+ struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
+ struct renesas_usb3_dma *dma;
+ int i;
+ bool ret = false;
+
+ if (usb3_req->req.length > USB3_DMA_MAX_XFER_SIZE_ALL_PRDS) {
+ dev_dbg(usb3_to_dev(usb3), "%s: the length is too big (%d)\n",
+ __func__, usb3_req->req.length);
+ return false;
+ }
+
+ /* The driver doesn't handle zero-length packet via dmac */
+ if (!usb3_req->req.length)
+ return false;
+
+ if (usb3_dma_mps_to_prd_word1(usb3_ep) == USB3_PRD1_MPS_RESERVED)
+ return false;
+
+ usb3_for_each_dma(usb3, dma, i) {
+ if (dma->used)
+ continue;
+
+ if (usb_gadget_map_request(&usb3->gadget, &usb3_req->req,
+ usb3_ep->dir_in) < 0)
+ break;
+
+ dma->used = true;
+ usb3_ep->dma = dma;
+ ret = true;
+ break;
+ }
+
+ return ret;
+}
+
+static void usb3_dma_put_setting_area(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req)
+{
+ struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
+ int i;
+ struct renesas_usb3_dma *dma;
+
+ usb3_for_each_dma(usb3, dma, i) {
+ if (usb3_ep->dma == dma) {
+ usb_gadget_unmap_request(&usb3->gadget, &usb3_req->req,
+ usb3_ep->dir_in);
+ dma->used = false;
+ usb3_ep->dma = NULL;
+ break;
+ }
+ }
+}
+
+static void usb3_dma_fill_prd(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req)
+{
+ struct renesas_usb3_prd *cur_prd = usb3_ep->dma->prd;
+ u32 remain = usb3_req->req.length;
+ u32 dma = usb3_req->req.dma;
+ u32 len;
+ int i = 0;
+
+ do {
+ len = min_t(u32, remain, USB3_DMA_MAX_XFER_SIZE) &
+ USB3_PRD1_SIZE_MASK;
+ cur_prd->word1 = usb3_dma_mps_to_prd_word1(usb3_ep) |
+ USB3_PRD1_B_INC | len;
+ cur_prd->bap = dma;
+ remain -= len;
+ dma += len;
+ if (!remain || (i + 1) < USB3_DMA_NUM_PRD_ENTRIES)
+ break;
+
+ cur_prd++;
+ i++;
+ } while (1);
+
+ cur_prd->word1 |= USB3_PRD1_E | USB3_PRD1_INT;
+ if (usb3_ep->dir_in)
+ cur_prd->word1 |= USB3_PRD1_LST;
+}
+
+static void usb3_dma_kick_prd(struct renesas_usb3_ep *usb3_ep)
+{
+ struct renesas_usb3_dma *dma = usb3_ep->dma;
+ struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
+ u32 dma_con = DMA_COM_PIPE_NO(usb3_ep->num) | DMA_CON_PRD_EN;
+
+ if (usb3_ep->dir_in)
+ dma_con |= DMA_CON_PIPE_DIR;
+
+ wmb(); /* prd entries should be in system memory here */
+
+ usb3_write(usb3, 1 << usb3_ep->num, USB3_DMA_INT_STA);
+ usb3_write(usb3, AXI_INT_PRDEN_CLR_STA(dma->num) |
+ AXI_INT_PRDERR_STA(dma->num), USB3_AXI_INT_STA);
+
+ usb3_write(usb3, dma->prd_dma, USB3_DMA_CH0_PRD_ADR(dma->num));
+ usb3_write(usb3, dma_con, USB3_DMA_CH0_CON(dma->num));
+ usb3_enable_dma_irq(usb3, usb3_ep->num);
+}
+
+static void usb3_dma_stop_prd(struct renesas_usb3_ep *usb3_ep)
+{
+ struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
+ struct renesas_usb3_dma *dma = usb3_ep->dma;
+
+ usb3_disable_dma_irq(usb3, usb3_ep->num);
+ usb3_write(usb3, 0, USB3_DMA_CH0_CON(dma->num));
+}
+
+static int usb3_dma_update_status(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req)
+{
+ struct renesas_usb3_prd *cur_prd = usb3_ep->dma->prd;
+ struct usb_request *req = &usb3_req->req;
+ u32 remain, len;
+ int i = 0;
+ int status = 0;
+
+ rmb(); /* The controller updated prd entries */
+
+ do {
+ if (cur_prd->word1 & USB3_PRD1_D)
+ status = -EIO;
+ if (cur_prd->word1 & USB3_PRD1_E)
+ len = req->length % USB3_DMA_MAX_XFER_SIZE;
+ else
+ len = USB3_DMA_MAX_XFER_SIZE;
+ remain = cur_prd->word1 & USB3_PRD1_SIZE_MASK;
+ req->actual += len - remain;
+
+ if (cur_prd->word1 & USB3_PRD1_E ||
+ (i + 1) < USB3_DMA_NUM_PRD_ENTRIES)
+ break;
+
+ cur_prd++;
+ i++;
+ } while (1);
+
+ return status;
+}
+
+static bool usb3_dma_try_start(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req)
+{
+ struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
+
+ if (!use_dma)
+ return false;
+
+ if (usb3_dma_get_setting_area(usb3_ep, usb3_req)) {
+ usb3_pn_stop(usb3);
+ usb3_enable_dma_pipen(usb3);
+ usb3_dma_fill_prd(usb3_ep, usb3_req);
+ usb3_dma_kick_prd(usb3_ep);
+ usb3_pn_start(usb3);
+ return true;
+ }
+
+ return false;
+}
+
+static int usb3_dma_try_stop(struct renesas_usb3_ep *usb3_ep,
+ struct renesas_usb3_request *usb3_req)
+{
+ struct renesas_usb3 *usb3 = usb3_ep_to_usb3(usb3_ep);
+ unsigned long flags;
+ int status = 0;
+
+ spin_lock_irqsave(&usb3->lock, flags);
+ if (!usb3_ep->dma)
+ goto out;
+
+ if (!usb3_pn_change(usb3, usb3_ep->num))
+ usb3_disable_dma_pipen(usb3);
+ usb3_dma_stop_prd(usb3_ep);
+ status = usb3_dma_update_status(usb3_ep, usb3_req);
+ usb3_dma_put_setting_area(usb3_ep, usb3_req);
+
+out:
+ spin_unlock_irqrestore(&usb3->lock, flags);
+ return status;
+}
+
+static int renesas_usb3_dma_free_prd(struct renesas_usb3 *usb3,
+ struct device *dev)
+{
+ int i;
+ struct renesas_usb3_dma *dma;
+
+ usb3_for_each_dma(usb3, dma, i) {
+ if (dma->prd) {
+ dma_free_coherent(dev, USB3_DMA_MAX_XFER_SIZE,
+ dma->prd, dma->prd_dma);
+ dma->prd = NULL;
+ }
+ }
+
+ return 0;
+}
+
+static int renesas_usb3_dma_alloc_prd(struct renesas_usb3 *usb3,
+ struct device *dev)
+{
+ int i;
+ struct renesas_usb3_dma *dma;
+
+ if (!use_dma)
+ return 0;
+
+ usb3_for_each_dma(usb3, dma, i) {
+ dma->prd = dma_alloc_coherent(dev, USB3_DMA_PRD_SIZE,
+ &dma->prd_dma, GFP_KERNEL);
+ if (!dma->prd) {
+ renesas_usb3_dma_free_prd(usb3, dev);
+ return -ENOMEM;
+ }
+ dma->num = i + 1;
+ }
+
+ return 0;
+}
+
static void usb3_start_pipen(struct renesas_usb3_ep *usb3_ep,
struct renesas_usb3_request *usb3_req)
{
@@ -1078,6 +1419,10 @@ static void usb3_start_pipen(struct renesas_usb3_ep *usb3_ep,
goto out;
usb3_ep->started = true;
+
+ if (usb3_dma_try_start(usb3_ep, usb3_req))
+ goto out;
+
usb3_pn_start(usb3);
if (usb3_ep->dir_in) {
@@ -1549,6 +1894,7 @@ static void usb3_irq_epc_pipen(struct renesas_usb3 *usb3, int num)
pn_int_sta &= usb3_read(usb3, USB3_PN_INT_ENA);
usb3_write(usb3, pn_int_sta, USB3_PN_INT_STA);
spin_unlock(&usb3->lock);
+
if (pn_int_sta & PN_INT_LSTTR)
usb3_irq_epc_pipen_lsttr(usb3, num);
if (pn_int_sta & PN_INT_BFRDY)
@@ -1603,12 +1949,49 @@ static void usb3_irq_epc(struct renesas_usb3 *usb3)
}
}
+static void usb3_irq_dma_int(struct renesas_usb3 *usb3, u32 dma_sta)
+{
+ struct renesas_usb3_ep *usb3_ep;
+ struct renesas_usb3_request *usb3_req;
+ int i, status;
+
+ for (i = 0; i < usb3->num_usb3_eps; i++) {
+ if (!(dma_sta & DMA_INT(i)))
+ continue;
+
+ usb3_ep = usb3_get_ep(usb3, i);
+ if (!(usb3_read(usb3, USB3_AXI_INT_STA) &
+ AXI_INT_PRDEN_CLR_STA(usb3_ep->dma->num)))
+ continue;
+
+ usb3_req = usb3_get_request(usb3_ep);
+ status = usb3_dma_try_stop(usb3_ep, usb3_req);
+ usb3_request_done_pipen(usb3, usb3_ep, usb3_req, status);
+ }
+}
+
+static void usb3_irq_dma(struct renesas_usb3 *usb3)
+{
+ u32 dma_sta = usb3_read(usb3, USB3_DMA_INT_STA);
+
+ dma_sta &= usb3_read(usb3, USB3_DMA_INT_ENA);
+ if (dma_sta) {
+ usb3_write(usb3, dma_sta, USB3_DMA_INT_STA);
+ usb3_irq_dma_int(usb3, dma_sta);
+ }
+}
+
static irqreturn_t renesas_usb3_irq(int irq, void *_usb3)
{
struct renesas_usb3 *usb3 = _usb3;
irqreturn_t ret = IRQ_NONE;
u32 axi_int_sta = usb3_read(usb3, USB3_AXI_INT_STA);
+ if (axi_int_sta & AXI_INT_DMAINT) {
+ usb3_irq_dma(usb3);
+ ret = IRQ_HANDLED;
+ }
+
if (axi_int_sta & AXI_INT_EPCINT) {
usb3_irq_epc(usb3);
ret = IRQ_HANDLED;
@@ -1708,6 +2091,7 @@ static int renesas_usb3_ep_disable(struct usb_ep *_ep)
usb3_req = usb3_get_request(usb3_ep);
if (!usb3_req)
break;
+ usb3_dma_try_stop(usb3_ep, usb3_req);
usb3_request_done(usb3_ep, usb3_req, -ESHUTDOWN);
} while (1);
@@ -1755,6 +2139,7 @@ static int renesas_usb3_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
dev_dbg(usb3_to_dev(usb3), "ep_dequeue: ep%2d, %u\n", usb3_ep->num,
_req->length);
+ usb3_dma_try_stop(usb3_ep, usb3_req);
usb3_request_done_pipen(usb3, usb3_ep, usb3_req, -ECONNRESET);
return 0;
@@ -1917,6 +2302,7 @@ static int renesas_usb3_remove(struct platform_device *pdev)
device_remove_file(&pdev->dev, &dev_attr_role);
usb_del_gadget_udc(&usb3->gadget);
+ renesas_usb3_dma_free_prd(usb3, &pdev->dev);
__renesas_usb3_ep_free_request(usb3->ep0_req);
@@ -2111,6 +2497,10 @@ static int renesas_usb3_probe(struct platform_device *pdev)
if (!usb3->ep0_req)
return -ENOMEM;
+ ret = renesas_usb3_dma_alloc_prd(usb3, &pdev->dev);
+ if (ret < 0)
+ goto err_alloc_prd;
+
ret = usb_add_gadget_udc(&pdev->dev, &usb3->gadget);
if (ret < 0)
goto err_add_udc;
@@ -2129,6 +2519,9 @@ static int renesas_usb3_probe(struct platform_device *pdev)
usb_del_gadget_udc(&usb3->gadget);
err_add_udc:
+ renesas_usb3_dma_free_prd(usb3, &pdev->dev);
+
+err_alloc_prd:
__renesas_usb3_ep_free_request(usb3->ep0_req);
return ret;
--
1.9.1
