From c5de6467d2a54eb81b139f29b217d0394e8a790c Mon Sep 17 00:00:00 2001 From: Manuel Lauss Date: Sat, 22 Oct 2011 13:34:36 +0200 Subject: [PATCH] i2c-au1550: remove usage of volatile keyword Replace the usage of "volatile"s with register accessor functions. Signed-off-by: Manuel Lauss Signed-off-by: Ben Dooks --- 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 892b7f168eb4..5a5cb7386427 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 532828bc50e6..70b027c9037d 100644 --- a/drivers/i2c/busses/i2c-au1550.c +++ b/drivers/i2c/busses/i2c-au1550.c @@ -39,29 +39,42 @@ #include #include +#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); } -- 2.11.0