The hardware can only do DMA to 4 byte aligned addresses.
When this requirement is not met use PIO or a bounce buffer.
PIO is used when the buffer is small enough to directly
use the hardware data memory (2*maxpacket).
A bounce buffer is used for larger transfers.
Signed-off-by: Martin Fuzzey <mfuzzey@xxxxxxxxx>
---
drivers/usb/host/imx21-hcd.c | 196 +++++++++++++++++++++++++++++++++++-------
drivers/usb/host/imx21-hcd.h | 8 +-
2 files changed, 169 insertions(+), 35 deletions(-)
diff --git a/drivers/usb/host/imx21-hcd.c b/drivers/usb/host/imx21-hcd.c
index 890a41c..dd132eb 100644
--- a/drivers/usb/host/imx21-hcd.c
+++ b/drivers/usb/host/imx21-hcd.c
@@ -57,6 +57,7 @@
#include <linux/slab.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
+#include <linux/dma-mapping.h>
#include "imx21-hcd.h"
@@ -136,9 +137,18 @@ static int imx21_hc_get_frame(struct usb_hcd *hcd)
return wrap_frame(readl(imx21->regs + USBH_FRMNUB));
}
+static inline bool unsuitable_for_dma(dma_addr_t addr)
+{
+ return (addr & 3) != 0;
+}
#include "imx21-dbg.c"
+static void nonisoc_urb_completed_for_etd(
+ struct imx21 *imx21, struct etd_priv *etd, int status);
+static void schedule_nonisoc_etd(struct imx21 *imx21, struct urb *urb);
+static void free_dmem(struct imx21 *imx21, struct etd_priv *etd);
+
/* =========================================== */
/* ETD management */
/* =========================================== */
@@ -185,7 +195,8 @@ static void reset_etd(struct imx21 *imx21, int num)
etd_writel(imx21, num, i, 0);
etd->urb = NULL;
etd->ep = NULL;
- etd->td = NULL;;
+ etd->td = NULL;
+ etd->bounce_buffer = NULL;
}
static void free_etd(struct imx21 *imx21, int num)
@@ -221,26 +232,94 @@ static void setup_etd_dword0(struct imx21 *imx21,
((u32) maxpacket << DW0_MAXPKTSIZ));
}
-static void activate_etd(struct imx21 *imx21,
- int etd_num, dma_addr_t dma, u8 dir)
+/**
+ * Copy buffer to data controller data memory.
+ * We cannot use memcpy_toio() because the hardware requires 32bit writes
+ */
+static void copy_to_dmem(
+ struct imx21 *imx21, int dmem_offset, void *src, int count)
+{
+ void __iomem *dmem = imx21->regs + USBOTG_DMEM + dmem_offset;
+ u32 word = 0;
+ u8 *p = src;
+ int byte = 0;
+ int i;
+
+ for (i = 0; i < count; i++) {
+ byte = i % 4;
+ word += (*p++ << (byte * 8));
+ if (byte == 3) {
+ writel(word, dmem);
+ dmem += 4;
+ word = 0;
+ }
+ }
+
+ if (count && byte != 3)
+ writel(word, dmem);
+}
+
+static void activate_etd(struct imx21 *imx21, int etd_num, u8 dir)
{
u32 etd_mask = 1 << etd_num;
struct etd_priv *etd = &imx21->etd[etd_num];
+ if (etd->dma_handle && unsuitable_for_dma(etd->dma_handle)) {
+ /* For non aligned isoc the condition below is always true */
+ if (etd->len <= etd->dmem_size) {
+ /* Fits into data memory, use PIO */
+ if (dir != TD_DIR_IN) {
+ copy_to_dmem(imx21,
+ etd->dmem_offset,
+ etd->cpu_buffer, etd->len);
+ }
+ etd->dma_handle = 0;
+
+ } else {
+ /* Too big for data memory, use bounce buffer */
+ enum dma_data_direction dmadir;
+
+ if (dir == TD_DIR_IN) {
+ dmadir = DMA_FROM_DEVICE;
+ etd->bounce_buffer = kmalloc(etd->len,
+ GFP_ATOMIC);
+ } else {
+ dmadir = DMA_TO_DEVICE;
+ etd->bounce_buffer = kmemdup(etd->cpu_buffer,
+ etd->len,
+ GFP_ATOMIC);
+ }
+ if (!etd->bounce_buffer) {
+ dev_err(imx21->dev, "failed bounce alloc\n");
+ goto err_bounce_alloc;
+ }
+
+ etd->dma_handle =
+ dma_map_single(imx21->dev,
+ etd->bounce_buffer,
+ etd->len,
+ dmadir);
+ if (dma_mapping_error(imx21->dev, etd->dma_handle)) {
+ dev_err(imx21->dev, "failed bounce map\n");
+ goto err_bounce_map;
+ }
+ }
+ }
+
clear_toggle_bit(imx21, USBH_ETDDONESTAT, etd_mask);
set_register_bits(imx21, USBH_ETDDONEEN, etd_mask);
clear_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
clear_toggle_bit(imx21, USBH_YFILLSTAT, etd_mask);
- if (dma) {
+ if (etd->dma_handle) {
set_register_bits(imx21, USB_ETDDMACHANLCLR, etd_mask);
clear_toggle_bit(imx21, USBH_XBUFSTAT, etd_mask);
clear_toggle_bit(imx21, USBH_YBUFSTAT, etd_mask);
- writel(dma, imx21->regs + USB_ETDSMSA(etd_num));
+ writel(etd->dma_handle, imx21->regs + USB_ETDSMSA(etd_num));
set_register_bits(imx21, USB_ETDDMAEN, etd_mask);
} else {
if (dir != TD_DIR_IN) {
- /* need to set for ZLP */
+ /* need to set for ZLP and PIO */
set_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
set_toggle_bit(imx21, USBH_YFILLSTAT, etd_mask);
}
@@ -263,6 +342,14 @@ static void activate_etd(struct imx21 *imx21,
etd->active_count = 1;
writel(etd_mask, imx21->regs + USBH_ETDENSET);
+ return;
+
+err_bounce_map:
+ kfree(etd->bounce_buffer);
+
+err_bounce_alloc:
+ free_dmem(imx21, etd);
+ nonisoc_urb_completed_for_etd(imx21, etd, -ENOMEM);
}
/* =========================================== */
@@ -325,7 +412,7 @@ static void activate_queued_etd(struct imx21 *imx21,
etd->dmem_offset = dmem_offset;
urb_priv->active = 1;
- activate_etd(imx21, etd_num, etd->dma_handle, dir);
+ activate_etd(imx21, etd_num, dir);
}
static void free_dmem(struct imx21 *imx21, struct etd_priv *etd)
@@ -385,7 +472,6 @@ static void free_epdmem(struct imx21 *imx21, struct usb_host_endpoint *ep)
/* =========================================== */
/* End handling */
/* =========================================== */
-static void schedule_nonisoc_etd(struct imx21 *imx21, struct urb *urb);
/* Endpoint now idle - release it's ETD(s) or asssign to queued request */
static void ep_idle(struct imx21 *imx21, struct ep_priv *ep_priv)
@@ -448,6 +534,24 @@ __acquires(imx21->lock)
ep_idle(imx21, ep_priv);
}
+static void nonisoc_urb_completed_for_etd(
+ struct imx21 *imx21, struct etd_priv *etd, int status)
+{
+ struct usb_host_endpoint *ep = etd->ep;
+
+ urb_done(imx21->hcd, etd->urb, status);
+ etd->urb = NULL;
+
+ if (!list_empty(&ep->urb_list)) {
+ struct urb *urb = list_first_entry(
+ &ep->urb_list, struct urb, urb_list);
+
+ dev_vdbg(imx21->dev, "next URB %p\n", urb);
+ schedule_nonisoc_etd(imx21, urb);
+ }
+}
+
+
/* =========================================== */
/* ISOC Handling ... */
/* =========================================== */
@@ -500,6 +604,8 @@ too_late:
etd->ep = td->ep;
etd->urb = td->urb;
etd->len = td->len;
+ etd->dma_handle = td->dma_handle;
+ etd->cpu_buffer = td->cpu_buffer;
debug_isoc_submitted(imx21, cur_frame, td);
@@ -513,16 +619,17 @@ too_late:
(TD_NOTACCESSED << DW3_COMPCODE0) |
(td->len << DW3_PKTLEN0));
- activate_etd(imx21, etd_num, td->data, dir);
+ activate_etd(imx21, etd_num, dir);
}
}
-static void isoc_etd_done(struct usb_hcd *hcd, struct urb *urb, int etd_num)
+static void isoc_etd_done(struct usb_hcd *hcd, int etd_num)
{
struct imx21 *imx21 = hcd_to_imx21(hcd);
int etd_mask = 1 << etd_num;
- struct urb_priv *urb_priv = urb->hcpriv;
struct etd_priv *etd = imx21->etd + etd_num;
+ struct urb *urb = etd->urb;
+ struct urb_priv *urb_priv = urb->hcpriv;
struct td *td = etd->td;
struct usb_host_endpoint *ep = etd->ep;
int isoc_index = td->isoc_index;
@@ -556,8 +663,13 @@ static void isoc_etd_done(struct usb_hcd *hcd, struct urb *urb, int etd_num)
bytes_xfrd, td->len, urb, etd_num, isoc_index);
}
- if (dir_in)
+ if (dir_in) {
clear_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
+ if (!etd->dma_handle)
+ memcpy_fromio(etd->cpu_buffer,
+ imx21->regs + USBOTG_DMEM + etd->dmem_offset,
+ bytes_xfrd);
+ }
urb->actual_length += bytes_xfrd;
urb->iso_frame_desc[isoc_index].actual_length = bytes_xfrd;
@@ -716,12 +828,14 @@ static int imx21_hc_urb_enqueue_isoc(struct usb_hcd *hcd,
/* set up transfers */
td = urb_priv->isoc_td;
for (i = 0; i < urb->number_of_packets; i++, td++) {
+ unsigned int offset = urb->iso_frame_desc[i].offset;
td->ep = ep;
td->urb = urb;
td->len = urb->iso_frame_desc[i].length;
td->isoc_index = i;
td->frame = wrap_frame(urb->start_frame + urb->interval * i);
- td->data = urb->transfer_dma + urb->iso_frame_desc[i].offset;
+ td->dma_handle = urb->transfer_dma + offset;
+ td->cpu_buffer = urb->transfer_buffer + offset;
list_add_tail(&td->list, &ep_priv->td_list);
}
@@ -812,13 +926,15 @@ static void schedule_nonisoc_etd(struct imx21 *imx21, struct urb *urb)
if (usb_pipecontrol(pipe) && (state != US_CTRL_DATA)) {
if (state == US_CTRL_SETUP) {
dir = TD_DIR_SETUP;
+ if (unsuitable_for_dma(urb->setup_dma))
+ unmap_urb_setup_for_dma(imx21->hcd, urb);
etd->dma_handle = urb->setup_dma;
+ etd->cpu_buffer = urb->setup_packet;
bufround = 0;
count = 8;
datatoggle = TD_TOGGLE_DATA0;
} else { /* US_CTRL_ACK */
dir = usb_pipeout(pipe) ? TD_DIR_IN : TD_DIR_OUT;
- etd->dma_handle = urb->transfer_dma;
bufround = 0;
count = 0;
datatoggle = TD_TOGGLE_DATA1;
@@ -826,7 +942,11 @@ static void schedule_nonisoc_etd(struct imx21 *imx21, struct urb *urb)
} else {
dir = usb_pipeout(pipe) ? TD_DIR_OUT : TD_DIR_IN;
bufround = (dir == TD_DIR_IN) ? 1 : 0;
+ if (unsuitable_for_dma(urb->transfer_dma))
+ unmap_urb_for_dma(imx21->hcd, urb);
+
etd->dma_handle = urb->transfer_dma;
+ etd->cpu_buffer = urb->transfer_buffer;
if (usb_pipebulk(pipe) && (state == US_BULK0))
count = 0;
else
@@ -901,14 +1021,15 @@ static void schedule_nonisoc_etd(struct imx21 *imx21, struct urb *urb)
/* enable the ETD to kick off transfer */
dev_vdbg(imx21->dev, "Activating etd %d for %d bytes %s\n",
etd_num, count, dir != TD_DIR_IN ? "out" : "in");
- activate_etd(imx21, etd_num, etd->dma_handle, dir);
+ activate_etd(imx21, etd_num, dir);
}
-static void nonisoc_etd_done(struct usb_hcd *hcd, struct urb *urb, int etd_num)
+static void nonisoc_etd_done(struct usb_hcd *hcd, int etd_num)
{
struct imx21 *imx21 = hcd_to_imx21(hcd);
struct etd_priv *etd = &imx21->etd[etd_num];
+ struct urb *urb = etd->urb;
u32 etd_mask = 1 << etd_num;
struct urb_priv *urb_priv = urb->hcpriv;
int dir;
@@ -930,7 +1051,20 @@ static void nonisoc_etd_done(struct usb_hcd *hcd, struct urb *urb, int etd_num)
if (dir == TD_DIR_IN) {
clear_toggle_bit(imx21, USBH_XFILLSTAT, etd_mask);
clear_toggle_bit(imx21, USBH_YFILLSTAT, etd_mask);
+
+ if (etd->bounce_buffer) {
+ memcpy(etd->cpu_buffer, etd->bounce_buffer, bytes_xfrd);
+ dma_unmap_single(imx21->dev,
+ etd->dma_handle, etd->len, DMA_FROM_DEVICE);
+ } else if (!etd->dma_handle && bytes_xfrd) {/* PIO */
+ memcpy_fromio(etd->cpu_buffer,
+ imx21->regs + USBOTG_DMEM + etd->dmem_offset,
+ bytes_xfrd);
+ }
}
+
+ kfree(etd->bounce_buffer);
+ etd->bounce_buffer = NULL;
free_dmem(imx21, etd);
urb->error_count = 0;
@@ -988,24 +1122,15 @@ static void nonisoc_etd_done(struct usb_hcd *hcd, struct urb *urb, int etd_num)
break;
}
- if (!etd_done) {
+ if (etd_done)
+ nonisoc_urb_completed_for_etd(imx21, etd, cc_to_error[cc]);
+ else {
dev_vdbg(imx21->dev, "next state=%d\n", urb_priv->state);
schedule_nonisoc_etd(imx21, urb);
- } else {
- struct usb_host_endpoint *ep = urb->ep;
-
- urb_done(hcd, urb, cc_to_error[cc]);
- etd->urb = NULL;
-
- if (!list_empty(&ep->urb_list)) {
- urb = list_first_entry(&ep->urb_list,
- struct urb, urb_list);
- dev_vdbg(imx21->dev, "next URB %p\n", urb);
- schedule_nonisoc_etd(imx21, urb);
- }
}
}
+
static struct ep_priv *alloc_ep(void)
{
int i;
@@ -1146,9 +1271,13 @@ static int imx21_hc_urb_dequeue(struct usb_hcd *hcd, struct urb *urb,
} else if (urb_priv->active) {
int etd_num = ep_priv->etd[0];
if (etd_num != -1) {
+ struct etd_priv *etd = &imx21->etd[etd_num];
+
disactivate_etd(imx21, etd_num);
- free_dmem(imx21, &imx21->etd[etd_num]);
- imx21->etd[etd_num].urb = NULL;
+ free_dmem(imx21, etd);
+ etd->urb = NULL;
+ kfree(etd->bounce_buffer);
+ etd->bounce_buffer = NULL;
}
}
@@ -1248,9 +1377,9 @@ static void process_etds(struct usb_hcd *hcd, struct imx21 *imx21, int sof)
}
if (usb_pipeisoc(etd->urb->pipe))
- isoc_etd_done(hcd, etd->urb, etd_num);
+ isoc_etd_done(hcd, etd_num);
else
- nonisoc_etd_done(hcd, etd->urb, etd_num);
+ nonisoc_etd_done(hcd, etd_num);
}
/* only enable SOF interrupt if it may be needed for the kludge */
@@ -1718,6 +1847,7 @@ static int imx21_probe(struct platform_device *pdev)
}
imx21 = hcd_to_imx21(hcd);
+ imx21->hcd = hcd;
imx21->dev = &pdev->dev;
imx21->pdata = pdev->dev.platform_data;
if (!imx21->pdata)
diff --git a/drivers/usb/host/imx21-hcd.h b/drivers/usb/host/imx21-hcd.h
index 1b0d913..87b29fd 100644
--- a/drivers/usb/host/imx21-hcd.h
+++ b/drivers/usb/host/imx21-hcd.h
@@ -250,6 +250,7 @@
#define USBCTRL_USB_BYP (1 << 2)
#define USBCTRL_HOST1_TXEN_OE (1 << 1)
+#define USBOTG_DMEM 0x1000
/* Values in TD blocks */
#define TD_DIR_SETUP 0
@@ -346,8 +347,8 @@ struct td {
struct list_head list;
struct urb *urb;
struct usb_host_endpoint *ep;
- dma_addr_t data;
- unsigned long buf_addr;
+ dma_addr_t dma_handle;
+ void *cpu_buffer;
int len;
int frame;
int isoc_index;
@@ -360,6 +361,8 @@ struct etd_priv {
struct td *td;
struct list_head queue;
dma_addr_t dma_handle;
+ void *cpu_buffer;
+ void *bounce_buffer;
int alloc;
int len;
int dmem_size;
@@ -412,6 +415,7 @@ struct debug_isoc_trace {
struct imx21 {
spinlock_t lock;
struct device *dev;
+ struct usb_hcd *hcd;
struct mx21_usbh_platform_data *pdata;
struct list_head dmem_list;
struct list_head queue_for_etd; /* eps queued due to etd shortage */
--
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