Commit 8ee9d857 authored by Olof Johansson's avatar Olof Johansson Committed by David S. Miller
Browse files

pasemi: DMA engine management library



pasemi: DMA engine management library

Introduce a DMA management library to manage the various DMA resources
on the PA Semi SoCs. Since several drivers need to allocate these shared
resources, provide some abstractions as well as allocation/free functions
for channels, etc.
Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 40afa531
obj-y += setup.o pci.o time.o idle.o powersave.o iommu.o
obj-y += setup.o pci.o time.o idle.o powersave.o iommu.o dma_lib.o
obj-$(CONFIG_PPC_PASEMI_MDIO) += gpio_mdio.o
obj-$(CONFIG_ELECTRA_IDE) += electra_ide.o
obj-$(CONFIG_PPC_PASEMI_CPUFREQ) += cpufreq.o
/*
* Copyright (C) 2006-2007 PA Semi, Inc
*
* Common functions for DMA access on PA Semi PWRficient
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/of.h>
#include <asm/pasemi_dma.h>
#define MAX_TXCH 64
#define MAX_RXCH 64
static struct pasdma_status *dma_status;
static void __iomem *iob_regs;
static void __iomem *mac_regs[6];
static void __iomem *dma_regs;
static int base_hw_irq;
static int num_txch, num_rxch;
static struct pci_dev *dma_pdev;
/* Bitmaps to handle allocation of channels */
static DECLARE_BITMAP(txch_free, MAX_TXCH);
static DECLARE_BITMAP(rxch_free, MAX_RXCH);
/* pasemi_read_iob_reg - read IOB register
* @reg: Register to read (offset into PCI CFG space)
*/
unsigned int pasemi_read_iob_reg(unsigned int reg)
{
return in_le32(iob_regs+reg);
}
EXPORT_SYMBOL(pasemi_read_iob_reg);
/* pasemi_write_iob_reg - write IOB register
* @reg: Register to write to (offset into PCI CFG space)
* @val: Value to write
*/
void pasemi_write_iob_reg(unsigned int reg, unsigned int val)
{
out_le32(iob_regs+reg, val);
}
EXPORT_SYMBOL(pasemi_write_iob_reg);
/* pasemi_read_mac_reg - read MAC register
* @intf: MAC interface
* @reg: Register to read (offset into PCI CFG space)
*/
unsigned int pasemi_read_mac_reg(int intf, unsigned int reg)
{
return in_le32(mac_regs[intf]+reg);
}
EXPORT_SYMBOL(pasemi_read_mac_reg);
/* pasemi_write_mac_reg - write MAC register
* @intf: MAC interface
* @reg: Register to write to (offset into PCI CFG space)
* @val: Value to write
*/
void pasemi_write_mac_reg(int intf, unsigned int reg, unsigned int val)
{
out_le32(mac_regs[intf]+reg, val);
}
EXPORT_SYMBOL(pasemi_write_mac_reg);
/* pasemi_read_dma_reg - read DMA register
* @reg: Register to read (offset into PCI CFG space)
*/
unsigned int pasemi_read_dma_reg(unsigned int reg)
{
return in_le32(dma_regs+reg);
}
EXPORT_SYMBOL(pasemi_read_dma_reg);
/* pasemi_write_dma_reg - write DMA register
* @reg: Register to write to (offset into PCI CFG space)
* @val: Value to write
*/
void pasemi_write_dma_reg(unsigned int reg, unsigned int val)
{
out_le32(dma_regs+reg, val);
}
EXPORT_SYMBOL(pasemi_write_dma_reg);
static int pasemi_alloc_tx_chan(enum pasemi_dmachan_type type)
{
int bit;
int start, limit;
switch (type & (TXCHAN_EVT0|TXCHAN_EVT1)) {
case TXCHAN_EVT0:
start = 0;
limit = 10;
break;
case TXCHAN_EVT1:
start = 10;
limit = MAX_TXCH;
break;
default:
start = 0;
limit = MAX_TXCH;
break;
}
retry:
bit = find_next_bit(txch_free, MAX_TXCH, start);
if (bit >= limit)
return -ENOSPC;
if (!test_and_clear_bit(bit, txch_free))
goto retry;
return bit;
}
static void pasemi_free_tx_chan(int chan)
{
BUG_ON(test_bit(chan, txch_free));
set_bit(chan, txch_free);
}
static int pasemi_alloc_rx_chan(void)
{
int bit;
retry:
bit = find_first_bit(rxch_free, MAX_RXCH);
if (bit >= MAX_TXCH)
return -ENOSPC;
if (!test_and_clear_bit(bit, rxch_free))
goto retry;
return bit;
}
static void pasemi_free_rx_chan(int chan)
{
BUG_ON(test_bit(chan, rxch_free));
set_bit(chan, rxch_free);
}
/* pasemi_dma_alloc_chan - Allocate a DMA channel
* @type: Type of channel to allocate
* @total_size: Total size of structure to allocate (to allow for more
* room behind the structure to be used by the client)
* @offset: Offset in bytes from start of the total structure to the beginning
* of struct pasemi_dmachan. Needed when struct pasemi_dmachan is
* not the first member of the client structure.
*
* pasemi_dma_alloc_chan allocates a DMA channel for use by a client. The
* type argument specifies whether it's a RX or TX channel, and in the case
* of TX channels which group it needs to belong to (if any).
*
* Returns a pointer to the total structure allocated on success, NULL
* on failure.
*/
void *pasemi_dma_alloc_chan(enum pasemi_dmachan_type type,
int total_size, int offset)
{
void *buf;
struct pasemi_dmachan *chan;
int chno;
BUG_ON(total_size < sizeof(struct pasemi_dmachan));
buf = kzalloc(total_size, GFP_KERNEL);
if (!buf)
return NULL;
chan = buf + offset;
chan->priv = buf;
switch (type & (TXCHAN|RXCHAN)) {
case RXCHAN:
chno = pasemi_alloc_rx_chan();
chan->chno = chno;
chan->irq = irq_create_mapping(NULL,
base_hw_irq + num_txch + chno);
chan->status = &dma_status->rx_sta[chno];
break;
case TXCHAN:
chno = pasemi_alloc_tx_chan(type);
chan->chno = chno;
chan->irq = irq_create_mapping(NULL, base_hw_irq + chno);
chan->status = &dma_status->tx_sta[chno];
break;
}
chan->chan_type = type;
return chan;
}
EXPORT_SYMBOL(pasemi_dma_alloc_chan);
/* pasemi_dma_free_chan - Free a previously allocated channel
* @chan: Channel to free
*
* Frees a previously allocated channel. It will also deallocate any
* descriptor ring associated with the channel, if allocated.
*/
void pasemi_dma_free_chan(struct pasemi_dmachan *chan)
{
if (chan->ring_virt)
pasemi_dma_free_ring(chan);
switch (chan->chan_type & (RXCHAN|TXCHAN)) {
case RXCHAN:
pasemi_free_rx_chan(chan->chno);
break;
case TXCHAN:
pasemi_free_tx_chan(chan->chno);
break;
}
kfree(chan->priv);
}
EXPORT_SYMBOL(pasemi_dma_free_chan);
/* pasemi_dma_alloc_ring - Allocate descriptor ring for a channel
* @chan: Channel for which to allocate
* @ring_size: Ring size in 64-bit (8-byte) words
*
* Allocate a descriptor ring for a channel. Returns 0 on success, errno
* on failure. The passed in struct pasemi_dmachan is updated with the
* virtual and DMA addresses of the ring.
*/
int pasemi_dma_alloc_ring(struct pasemi_dmachan *chan, int ring_size)
{
BUG_ON(chan->ring_virt);
chan->ring_size = ring_size;
chan->ring_virt = dma_alloc_coherent(&dma_pdev->dev,
ring_size * sizeof(u64),
&chan->ring_dma, GFP_KERNEL);
if (!chan->ring_virt)
return -ENOMEM;
memset(chan->ring_virt, 0, ring_size * sizeof(u64));
return 0;
}
EXPORT_SYMBOL(pasemi_dma_alloc_ring);
/* pasemi_dma_free_ring - Free an allocated descriptor ring for a channel
* @chan: Channel for which to free the descriptor ring
*
* Frees a previously allocated descriptor ring for a channel.
*/
void pasemi_dma_free_ring(struct pasemi_dmachan *chan)
{
BUG_ON(!chan->ring_virt);
dma_free_coherent(&dma_pdev->dev, chan->ring_size * sizeof(u64),
chan->ring_virt, chan->ring_dma);
chan->ring_virt = NULL;
chan->ring_size = 0;
chan->ring_dma = 0;
}
EXPORT_SYMBOL(pasemi_dma_free_ring);
/* pasemi_dma_start_chan - Start a DMA channel
* @chan: Channel to start
* @cmdsta: Additional CCMDSTA/TCMDSTA bits to write
*
* Enables (starts) a DMA channel with optional additional arguments.
*/
void pasemi_dma_start_chan(const struct pasemi_dmachan *chan, const u32 cmdsta)
{
if (chan->chan_type == RXCHAN)
pasemi_write_dma_reg(PAS_DMA_RXCHAN_CCMDSTA(chan->chno),
cmdsta | PAS_DMA_RXCHAN_CCMDSTA_EN);
else
pasemi_write_dma_reg(PAS_DMA_TXCHAN_TCMDSTA(chan->chno),
cmdsta | PAS_DMA_TXCHAN_TCMDSTA_EN);
}
EXPORT_SYMBOL(pasemi_dma_start_chan);
/* pasemi_dma_stop_chan - Stop a DMA channel
* @chan: Channel to stop
*
* Stops (disables) a DMA channel. This is done by setting the ST bit in the
* CMDSTA register and waiting on the ACT (active) bit to clear, then
* finally disabling the whole channel.
*
* This function will only try for a short while for the channel to stop, if
* it doesn't it will return failure.
*
* Returns 1 on success, 0 on failure.
*/
#define MAX_RETRIES 5000
int pasemi_dma_stop_chan(const struct pasemi_dmachan *chan)
{
int reg, retries;
u32 sta;
if (chan->chan_type == RXCHAN) {
reg = PAS_DMA_RXCHAN_CCMDSTA(chan->chno);
pasemi_write_dma_reg(reg, PAS_DMA_RXCHAN_CCMDSTA_ST);
for (retries = 0; retries < MAX_RETRIES; retries++) {
sta = pasemi_read_dma_reg(reg);
if (!(sta & PAS_DMA_RXCHAN_CCMDSTA_ACT)) {
pasemi_write_dma_reg(reg, 0);
return 1;
}
cond_resched();
}
} else {
reg = PAS_DMA_TXCHAN_TCMDSTA(chan->chno);
pasemi_write_dma_reg(reg, PAS_DMA_TXCHAN_TCMDSTA_ST);
for (retries = 0; retries < MAX_RETRIES; retries++) {
sta = pasemi_read_dma_reg(reg);
if (!(sta & PAS_DMA_TXCHAN_TCMDSTA_ACT)) {
pasemi_write_dma_reg(reg, 0);
return 1;
}
cond_resched();
}
}
return 0;
}
EXPORT_SYMBOL(pasemi_dma_stop_chan);
/* pasemi_dma_alloc_buf - Allocate a buffer to use for DMA
* @chan: Channel to allocate for
* @size: Size of buffer in bytes
* @handle: DMA handle
*
* Allocate a buffer to be used by the DMA engine for read/write,
* similar to dma_alloc_coherent().
*
* Returns the virtual address of the buffer, or NULL in case of failure.
*/
void *pasemi_dma_alloc_buf(struct pasemi_dmachan *chan, int size,
dma_addr_t *handle)
{
return dma_alloc_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL);
}
EXPORT_SYMBOL(pasemi_dma_alloc_buf);
/* pasemi_dma_free_buf - Free a buffer used for DMA
* @chan: Channel the buffer was allocated for
* @size: Size of buffer in bytes
* @handle: DMA handle
*
* Frees a previously allocated buffer.
*/
void pasemi_dma_free_buf(struct pasemi_dmachan *chan, int size,
dma_addr_t *handle)
{
dma_free_coherent(&dma_pdev->dev, size, handle, GFP_KERNEL);
}
EXPORT_SYMBOL(pasemi_dma_free_buf);
static void *map_onedev(struct pci_dev *p, int index)
{
struct device_node *dn;
void __iomem *ret;
dn = pci_device_to_OF_node(p);
if (!dn)
goto fallback;
ret = of_iomap(dn, index);
if (!ret)
goto fallback;
return ret;
fallback:
/* This is hardcoded and ugly, but we have some firmware versions
* that don't provide the register space in the device tree. Luckily
* they are at well-known locations so we can just do the math here.
*/
return ioremap(0xe0000000 + (p->devfn << 12), 0x2000);
}
/* pasemi_dma_init - Initialize the PA Semi DMA library
*
* This function initializes the DMA library. It must be called before
* any other function in the library.
*
* Returns 0 on success, errno on failure.
*/
int pasemi_dma_init(void)
{
static spinlock_t init_lock = SPIN_LOCK_UNLOCKED;
struct pci_dev *iob_pdev;
struct pci_dev *pdev;
struct resource res;
struct device_node *dn;
int i, intf, err = 0;
u32 tmp;
if (!machine_is(pasemi))
return -ENODEV;
spin_lock(&init_lock);
/* Make sure we haven't already initialized */
if (dma_pdev)
goto out;
iob_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa001, NULL);
if (!iob_pdev) {
BUG();
printk(KERN_WARNING "Can't find I/O Bridge\n");
err = -ENODEV;
goto out;
}
iob_regs = map_onedev(iob_pdev, 0);
dma_pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa007, NULL);
if (!dma_pdev) {
BUG();
printk(KERN_WARNING "Can't find DMA controller\n");
err = -ENODEV;
goto out;
}
dma_regs = map_onedev(dma_pdev, 0);
base_hw_irq = virq_to_hw(dma_pdev->irq);
pci_read_config_dword(dma_pdev, PAS_DMA_CAP_TXCH, &tmp);
num_txch = (tmp & PAS_DMA_CAP_TXCH_TCHN_M) >> PAS_DMA_CAP_TXCH_TCHN_S;
pci_read_config_dword(dma_pdev, PAS_DMA_CAP_RXCH, &tmp);
num_rxch = (tmp & PAS_DMA_CAP_RXCH_RCHN_M) >> PAS_DMA_CAP_RXCH_RCHN_S;
intf = 0;
for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, NULL);
pdev;
pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa006, pdev))
mac_regs[intf++] = map_onedev(pdev, 0);
pci_dev_put(pdev);
for (pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, NULL);
pdev;
pdev = pci_get_device(PCI_VENDOR_ID_PASEMI, 0xa005, pdev))
mac_regs[intf++] = map_onedev(pdev, 0);
pci_dev_put(pdev);
dn = pci_device_to_OF_node(iob_pdev);
if (dn)
err = of_address_to_resource(dn, 1, &res);
if (!dn || err) {
/* Fallback for old firmware */
res.start = 0xfd800000;
res.end = res.start + 0x1000;
}
dma_status = __ioremap(res.start, res.end-res.start, 0);
pci_dev_put(iob_pdev);
for (i = 0; i < MAX_TXCH; i++)
__set_bit(i, txch_free);
for (i = 0; i < MAX_RXCH; i++)
__set_bit(i, rxch_free);
printk(KERN_INFO "PA Semi PWRficient DMA library initialized "
"(%d tx, %d rx channels)\n", num_txch, num_rxch);
out:
spin_unlock(&init_lock);
return err;
}
......@@ -9,6 +9,7 @@ extern void __devinit pas_pci_dma_dev_setup(struct pci_dev *dev);
extern void __iomem *pasemi_pci_getcfgaddr(struct pci_dev *dev, int offset);
extern void __init alloc_iobmap_l2(void);
extern void __init pasemi_map_registers(void);
/* Power savings modes, implemented in asm */
extern void idle_spin(void);
......
......@@ -33,11 +33,27 @@ struct pasdma_status {
* device. Use the normal PCI config access functions for them.
*/
enum {
PAS_DMA_CAP_TXCH = 0x44, /* Transmit Channel Info */
PAS_DMA_CAP_RXCH = 0x48, /* Transmit Channel Info */
PAS_DMA_CAP_IFI = 0x4c, /* Interface Info */
PAS_DMA_COM_TXCMD = 0x100, /* Transmit Command Register */
PAS_DMA_COM_TXSTA = 0x104, /* Transmit Status Register */
PAS_DMA_COM_RXCMD = 0x108, /* Receive Command Register */
PAS_DMA_COM_RXSTA = 0x10c, /* Receive Status Register */
};
#define PAS_DMA_CAP_TXCH_TCHN_M 0x00ff0000 /* # of TX channels */
#define PAS_DMA_CAP_TXCH_TCHN_S 16
#define PAS_DMA_CAP_RXCH_RCHN_M 0x00ff0000 /* # of RX channels */
#define PAS_DMA_CAP_RXCH_RCHN_S 16
#define PAS_DMA_CAP_IFI_IOFF_M 0xff000000 /* Cfg reg for intf pointers */
#define PAS_DMA_CAP_IFI_IOFF_S 24
#define PAS_DMA_CAP_IFI_NIN_M 0x00ff0000 /* # of interfaces */
#define PAS_DMA_CAP_IFI_NIN_S 16
#define PAS_DMA_COM_TXCMD_EN 0x00000001 /* enable */
#define PAS_DMA_COM_TXSTA_ACT 0x00000001 /* active */
#define PAS_DMA_COM_RXCMD_EN 0x00000001 /* enable */
......@@ -388,4 +404,64 @@ enum {
CTRL_CMD_REG_M)
/* Prototypes for the shared DMA functions in the platform code. */
/* DMA TX Channel type. Right now only limitations used are event types 0/1,
* for event-triggered DMA transactions.
*/
enum pasemi_dmachan_type {
RXCHAN = 0, /* Any RX chan */
TXCHAN = 1, /* Any TX chan */
TXCHAN_EVT0 = 0x1001, /* TX chan in event class 0 (chan 0-9) */
TXCHAN_EVT1 = 0x2001, /* TX chan in event class 1 (chan 10-19) */
};
struct pasemi_dmachan {
int chno; /* Channel number */
enum pasemi_dmachan_type chan_type; /* TX / RX */
u64 *status; /* Ptr to cacheable status */
int irq; /* IRQ used by channel */
unsigned int ring_size; /* size of allocated ring */
dma_addr_t ring_dma; /* DMA address for ring */
u64 *ring_virt; /* Virt address for ring */
void *priv; /* Ptr to start of client struct */
};
/* Read/write the different registers in the I/O Bridge, Ethernet
* and DMA Controller
*/
extern unsigned int pasemi_read_iob_reg(unsigned int reg);
extern void pasemi_write_iob_reg(unsigned int reg, unsigned int val);
extern unsigned int pasemi_read_mac_reg(int intf, unsigned int reg);
extern void pasemi_write_mac_reg(int intf, unsigned int reg, unsigned int val);
extern unsigned int pasemi_read_dma_reg(unsigned int reg);
extern void pasemi_write_dma_reg(unsigned int reg, unsigned int val);
/* Channel management routines */
extern void *pasemi_dma_alloc_chan(enum pasemi_dmachan_type type,
int total_size, int offset);
extern void pasemi_dma_free_chan(struct pasemi_dmachan *chan);
extern void pasemi_dma_start_chan(const struct pasemi_dmachan *chan,
const u32 cmdsta);
extern int pasemi_dma_stop_chan(const struct pasemi_dmachan *chan);
/* Common routines to allocate rings and buffers */
extern int pasemi_dma_alloc_ring(struct pasemi_dmachan *chan, int ring_size);
extern void pasemi_dma_free_ring(struct pasemi_dmachan *chan);
extern void *pasemi_dma_alloc_buf(struct pasemi_dmachan *chan, int size,
dma_addr_t *handle);
extern void pasemi_dma_free_buf(struct pasemi_dmachan *chan, int size,
dma_addr_t *handle);
/* Initialize the library, must be called before any other functions */
extern int pasemi_dma_init(void);
#endif /* ASM_PASEMI_DMA_H */
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