* [PATCH V2 1/4] i2c/au1550: remove usage of volatile keyword
[not found] ` <1315227609-9310-1-git-send-email-manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
@ 2011-09-05 13:00 ` Manuel Lauss
2011-09-05 13:00 ` [PATCH V2 2/4] i2c/au1550: remove unused ack_timeout Manuel Lauss
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Manuel Lauss @ 2011-09-05 13:00 UTC (permalink / raw)
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA; +Cc: Manuel Lauss
Replace the usage of "volatile"s with register accessor functions.
Signed-off-by: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
---
V2: no changes
arch/mips/include/asm/mach-au1x00/au1xxx_psc.h | 13 --
drivers/i2c/busses/i2c-au1550.c | 252 +++++++++--------------
2 files changed, 99 insertions(+), 166 deletions(-)
diff --git a/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h b/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h
index 892b7f1..5a5cb73 100644
--- a/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h
+++ b/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h
@@ -394,19 +394,6 @@ typedef struct psc_spi {
#define PSC_SPITXRX_LC (1 << 29)
#define PSC_SPITXRX_SR (1 << 28)
-/* PSC in SMBus (I2C) Mode. */
-typedef struct psc_smb {
- u32 psc_sel;
- u32 psc_ctrl;
- u32 psc_smbcfg;
- u32 psc_smbmsk;
- u32 psc_smbpcr;
- u32 psc_smbstat;
- u32 psc_smbevnt;
- u32 psc_smbtxrx;
- u32 psc_smbtmr;
-} psc_smb_t;
-
/* SMBus Config Register. */
#define PSC_SMBCFG_RT_MASK (3 << 30)
#define PSC_SMBCFG_RT_FIFO1 (0 << 30)
diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c
index 532828b..70b027c 100644
--- a/drivers/i2c/busses/i2c-au1550.c
+++ b/drivers/i2c/busses/i2c-au1550.c
@@ -39,29 +39,42 @@
#include <asm/mach-au1x00/au1xxx.h>
#include <asm/mach-au1x00/au1xxx_psc.h>
+#define PSC_SEL 0x00
+#define PSC_CTRL 0x04
+#define PSC_SMBCFG 0x08
+#define PSC_SMBMSK 0x0C
+#define PSC_SMBPCR 0x10
+#define PSC_SMBSTAT 0x14
+#define PSC_SMBEVNT 0x18
+#define PSC_SMBTXRX 0x1C
+#define PSC_SMBTMR 0x20
+
struct i2c_au1550_data {
- u32 psc_base;
+ void __iomem *psc_base;
int xfer_timeout;
int ack_timeout;
struct i2c_adapter adap;
struct resource *ioarea;
};
-static int
-wait_xfer_done(struct i2c_au1550_data *adap)
+static inline void WR(struct i2c_au1550_data *a, int r, unsigned long v)
{
- u32 stat;
- int i;
- volatile psc_smb_t *sp;
+ __raw_writel(v, a->psc_base + r);
+ wmb();
+}
- sp = (volatile psc_smb_t *)(adap->psc_base);
+static inline unsigned long RD(struct i2c_au1550_data *a, int r)
+{
+ return __raw_readl(a->psc_base + r);
+}
- /* Wait for Tx Buffer Empty
- */
+static int wait_xfer_done(struct i2c_au1550_data *adap)
+{
+ int i;
+
+ /* Wait for Tx Buffer Empty */
for (i = 0; i < adap->xfer_timeout; i++) {
- stat = sp->psc_smbstat;
- au_sync();
- if ((stat & PSC_SMBSTAT_TE) != 0)
+ if (RD(adap, PSC_SMBSTAT) & PSC_SMBSTAT_TE)
return 0;
udelay(1);
@@ -70,41 +83,27 @@ wait_xfer_done(struct i2c_au1550_data *adap)
return -ETIMEDOUT;
}
-static int
-wait_ack(struct i2c_au1550_data *adap)
+static int wait_ack(struct i2c_au1550_data *adap)
{
- u32 stat;
- volatile psc_smb_t *sp;
+ unsigned long stat;
if (wait_xfer_done(adap))
return -ETIMEDOUT;
- sp = (volatile psc_smb_t *)(adap->psc_base);
-
- stat = sp->psc_smbevnt;
- au_sync();
-
+ stat = RD(adap, PSC_SMBEVNT);
if ((stat & (PSC_SMBEVNT_DN | PSC_SMBEVNT_AN | PSC_SMBEVNT_AL)) != 0)
return -ETIMEDOUT;
return 0;
}
-static int
-wait_master_done(struct i2c_au1550_data *adap)
+static int wait_master_done(struct i2c_au1550_data *adap)
{
- u32 stat;
- int i;
- volatile psc_smb_t *sp;
+ int i;
- sp = (volatile psc_smb_t *)(adap->psc_base);
-
- /* Wait for Master Done.
- */
+ /* Wait for Master Done. */
for (i = 0; i < adap->xfer_timeout; i++) {
- stat = sp->psc_smbevnt;
- au_sync();
- if ((stat & PSC_SMBEVNT_MD) != 0)
+ if ((RD(adap, PSC_SMBEVNT) & PSC_SMBEVNT_MD) != 0)
return 0;
udelay(1);
}
@@ -115,29 +114,20 @@ wait_master_done(struct i2c_au1550_data *adap)
static int
do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd, int q)
{
- volatile psc_smb_t *sp;
- u32 stat;
+ unsigned long stat;
- sp = (volatile psc_smb_t *)(adap->psc_base);
-
- /* Reset the FIFOs, clear events.
- */
- stat = sp->psc_smbstat;
- sp->psc_smbevnt = PSC_SMBEVNT_ALLCLR;
- au_sync();
+ /* Reset the FIFOs, clear events. */
+ stat = RD(adap, PSC_SMBSTAT);
+ WR(adap, PSC_SMBEVNT, PSC_SMBEVNT_ALLCLR);
if (!(stat & PSC_SMBSTAT_TE) || !(stat & PSC_SMBSTAT_RE)) {
- sp->psc_smbpcr = PSC_SMBPCR_DC;
- au_sync();
- do {
- stat = sp->psc_smbpcr;
- au_sync();
- } while ((stat & PSC_SMBPCR_DC) != 0);
+ WR(adap, PSC_SMBPCR, PSC_SMBPCR_DC);
+ while ((RD(adap, PSC_SMBPCR) & PSC_SMBPCR_DC) != 0)
+ cpu_relax();
udelay(50);
}
- /* Write out the i2c chip address and specify operation
- */
+ /* Write out the i2c chip address and specify operation */
addr <<= 1;
if (rd)
addr |= 1;
@@ -146,56 +136,42 @@ do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd, int q)
if (q)
addr |= PSC_SMBTXRX_STP;
- /* Put byte into fifo, start up master.
- */
- sp->psc_smbtxrx = addr;
- au_sync();
- sp->psc_smbpcr = PSC_SMBPCR_MS;
- au_sync();
+ /* Put byte into fifo, start up master. */
+ WR(adap, PSC_SMBTXRX, addr);
+ WR(adap, PSC_SMBPCR, PSC_SMBPCR_MS);
if (wait_ack(adap))
return -EIO;
return (q) ? wait_master_done(adap) : 0;
}
-static u32
-wait_for_rx_byte(struct i2c_au1550_data *adap, u32 *ret_data)
+static int wait_for_rx_byte(struct i2c_au1550_data *adap, unsigned char *out)
{
- int j;
- u32 data, stat;
- volatile psc_smb_t *sp;
+ int j;
if (wait_xfer_done(adap))
return -EIO;
- sp = (volatile psc_smb_t *)(adap->psc_base);
-
j = adap->xfer_timeout * 100;
do {
j--;
if (j <= 0)
return -EIO;
- stat = sp->psc_smbstat;
- au_sync();
- if ((stat & PSC_SMBSTAT_RE) == 0)
+ if ((RD(adap, PSC_SMBSTAT) & PSC_SMBSTAT_RE) == 0)
j = 0;
else
udelay(1);
} while (j > 0);
- data = sp->psc_smbtxrx;
- au_sync();
- *ret_data = data;
+
+ *out = RD(adap, PSC_SMBTXRX);
return 0;
}
-static int
-i2c_read(struct i2c_au1550_data *adap, unsigned char *buf,
+static int i2c_read(struct i2c_au1550_data *adap, unsigned char *buf,
unsigned int len)
{
- int i;
- u32 data;
- volatile psc_smb_t *sp;
+ int i;
if (len == 0)
return 0;
@@ -204,62 +180,46 @@ i2c_read(struct i2c_au1550_data *adap, unsigned char *buf,
* zero bytes for timing, waiting for bytes to appear in the
* receive fifo, then reading the bytes.
*/
-
- sp = (volatile psc_smb_t *)(adap->psc_base);
-
i = 0;
- while (i < (len-1)) {
- sp->psc_smbtxrx = 0;
- au_sync();
- if (wait_for_rx_byte(adap, &data))
+ while (i < (len - 1)) {
+ WR(adap, PSC_SMBTXRX, 0);
+ if (wait_for_rx_byte(adap, &buf[i]))
return -EIO;
- buf[i] = data;
i++;
}
- /* The last byte has to indicate transfer done.
- */
- sp->psc_smbtxrx = PSC_SMBTXRX_STP;
- au_sync();
+ /* The last byte has to indicate transfer done. */
+ WR(adap, PSC_SMBTXRX, PSC_SMBTXRX_STP);
if (wait_master_done(adap))
return -EIO;
- data = sp->psc_smbtxrx;
- au_sync();
- buf[i] = data;
+ buf[i] = (unsigned char)(RD(adap, PSC_SMBTXRX) & 0xff);
return 0;
}
-static int
-i2c_write(struct i2c_au1550_data *adap, unsigned char *buf,
+static int i2c_write(struct i2c_au1550_data *adap, unsigned char *buf,
unsigned int len)
{
- int i;
- u32 data;
- volatile psc_smb_t *sp;
+ int i;
+ unsigned long data;
if (len == 0)
return 0;
- sp = (volatile psc_smb_t *)(adap->psc_base);
-
i = 0;
while (i < (len-1)) {
data = buf[i];
- sp->psc_smbtxrx = data;
- au_sync();
+ WR(adap, PSC_SMBTXRX, data);
if (wait_ack(adap))
return -EIO;
i++;
}
- /* The last byte has to indicate transfer done.
- */
+ /* The last byte has to indicate transfer done. */
data = buf[i];
data |= PSC_SMBTXRX_STP;
- sp->psc_smbtxrx = data;
- au_sync();
+ WR(adap, PSC_SMBTXRX, data);
if (wait_master_done(adap))
return -EIO;
return 0;
@@ -269,12 +229,10 @@ static int
au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
{
struct i2c_au1550_data *adap = i2c_adap->algo_data;
- volatile psc_smb_t *sp = (volatile psc_smb_t *)adap->psc_base;
struct i2c_msg *p;
int i, err = 0;
- sp->psc_ctrl = PSC_CTRL_ENABLE;
- au_sync();
+ WR(adap, PSC_CTRL, PSC_CTRL_ENABLE);
for (i = 0; !err && i < num; i++) {
p = &msgs[i];
@@ -293,14 +251,12 @@ au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
if (err == 0)
err = num;
- sp->psc_ctrl = PSC_CTRL_SUSPEND;
- au_sync();
+ WR(adap, PSC_CTRL, PSC_CTRL_SUSPEND);
return err;
}
-static u32
-au1550_func(struct i2c_adapter *adap)
+static u32 au1550_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}
@@ -312,57 +268,45 @@ static const struct i2c_algorithm au1550_algo = {
static void i2c_au1550_setup(struct i2c_au1550_data *priv)
{
- volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
- u32 stat;
-
- sp->psc_ctrl = PSC_CTRL_DISABLE;
- au_sync();
- sp->psc_sel = PSC_SEL_PS_SMBUSMODE;
- sp->psc_smbcfg = 0;
- au_sync();
- sp->psc_ctrl = PSC_CTRL_ENABLE;
- au_sync();
- do {
- stat = sp->psc_smbstat;
- au_sync();
- } while ((stat & PSC_SMBSTAT_SR) == 0);
+ unsigned long cfg;
- sp->psc_smbcfg = (PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 |
- PSC_SMBCFG_DD_DISABLE);
+ WR(priv, PSC_CTRL, PSC_CTRL_DISABLE);
+ WR(priv, PSC_SEL, PSC_SEL_PS_SMBUSMODE);
+ WR(priv, PSC_SMBCFG, 0);
+ WR(priv, PSC_CTRL, PSC_CTRL_ENABLE);
+ while ((RD(priv, PSC_SMBSTAT) & PSC_SMBSTAT_SR) == 0)
+ cpu_relax();
+
+ cfg = PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 | PSC_SMBCFG_DD_DISABLE;
+ WR(priv, PSC_SMBCFG, cfg);
/* Divide by 8 to get a 6.25 MHz clock. The later protocol
* timings are based on this clock.
*/
- sp->psc_smbcfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8);
- sp->psc_smbmsk = PSC_SMBMSK_ALLMASK;
- au_sync();
+ cfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8);
+ WR(priv, PSC_SMBCFG, cfg);
+ WR(priv, PSC_SMBMSK, PSC_SMBMSK_ALLMASK);
/* Set the protocol timer values. See Table 71 in the
* Au1550 Data Book for standard timing values.
*/
- sp->psc_smbtmr = PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \
+ WR(priv, PSC_SMBTMR, PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \
PSC_SMBTMR_SET_PU(15) | PSC_SMBTMR_SET_SH(15) | \
PSC_SMBTMR_SET_SU(15) | PSC_SMBTMR_SET_CL(15) | \
- PSC_SMBTMR_SET_CH(15);
- au_sync();
+ PSC_SMBTMR_SET_CH(15));
- sp->psc_smbcfg |= PSC_SMBCFG_DE_ENABLE;
- do {
- stat = sp->psc_smbstat;
- au_sync();
- } while ((stat & PSC_SMBSTAT_SR) == 0);
+ cfg |= PSC_SMBCFG_DE_ENABLE;
+ WR(priv, PSC_SMBCFG, cfg);
+ while ((RD(priv, PSC_SMBSTAT) & PSC_SMBSTAT_SR) == 0)
+ cpu_relax();
- sp->psc_ctrl = PSC_CTRL_SUSPEND;
- au_sync();
+ WR(priv, PSC_CTRL, PSC_CTRL_SUSPEND);
}
static void i2c_au1550_disable(struct i2c_au1550_data *priv)
{
- volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
-
- sp->psc_smbcfg = 0;
- sp->psc_ctrl = PSC_CTRL_DISABLE;
- au_sync();
+ WR(priv, PSC_SMBCFG, 0);
+ WR(priv, PSC_CTRL, PSC_CTRL_DISABLE);
}
/*
@@ -396,7 +340,11 @@ i2c_au1550_probe(struct platform_device *pdev)
goto out_mem;
}
- priv->psc_base = CKSEG1ADDR(r->start);
+ priv->psc_base = ioremap(r->start, resource_size(r));
+ if (!priv->psc_base) {
+ ret = -EIO;
+ goto out_map;
+ }
priv->xfer_timeout = 200;
priv->ack_timeout = 200;
@@ -406,8 +354,7 @@ i2c_au1550_probe(struct platform_device *pdev)
priv->adap.dev.parent = &pdev->dev;
strlcpy(priv->adap.name, "Au1xxx PSC I2C", sizeof(priv->adap.name));
- /* Now, set up the PSC for SMBus PIO mode.
- */
+ /* Now, set up the PSC for SMBus PIO mode. */
i2c_au1550_setup(priv);
ret = i2c_add_numbered_adapter(&priv->adap);
@@ -417,7 +364,8 @@ i2c_au1550_probe(struct platform_device *pdev)
}
i2c_au1550_disable(priv);
-
+ iounmap(priv->psc_base);
+out_map:
release_resource(priv->ioarea);
kfree(priv->ioarea);
out_mem:
@@ -426,14 +374,14 @@ out:
return ret;
}
-static int __devexit
-i2c_au1550_remove(struct platform_device *pdev)
+static int __devexit i2c_au1550_remove(struct platform_device *pdev)
{
struct i2c_au1550_data *priv = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL);
i2c_del_adapter(&priv->adap);
i2c_au1550_disable(priv);
+ iounmap(priv->psc_base);
release_resource(priv->ioarea);
kfree(priv->ioarea);
kfree(priv);
@@ -476,14 +424,12 @@ static struct platform_driver au1xpsc_smbus_driver = {
.resume = i2c_au1550_resume,
};
-static int __init
-i2c_au1550_init(void)
+static int __init i2c_au1550_init(void)
{
return platform_driver_register(&au1xpsc_smbus_driver);
}
-static void __exit
-i2c_au1550_exit(void)
+static void __exit i2c_au1550_exit(void)
{
platform_driver_unregister(&au1xpsc_smbus_driver);
}
--
1.7.6.1
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