i2c-au1550: remove usage of volatile keyword
authorManuel Lauss <manuel.lauss@googlemail.com>
Sat, 22 Oct 2011 11:34:36 +0000 (13:34 +0200)
committerBen Dooks <ben-linux@fluff.org>
Sat, 29 Oct 2011 10:14:09 +0000 (11:14 +0100)
Replace the usage of "volatile"s with register accessor functions.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
arch/mips/include/asm/mach-au1x00/au1xxx_psc.h
drivers/i2c/busses/i2c-au1550.c

index 892b7f1..5a5cb73 100644 (file)
@@ -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)
index 532828b..70b027c 100644 (file)
 #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);
 }