diff options
author | Heiner Kallweit <hkallweit1@gmail.com> | 2025-03-12 20:07:23 +0100 |
---|---|---|
committer | Andi Shyti <andi.shyti@kernel.org> | 2025-03-20 22:30:52 +0100 |
commit | 4a3f77ea77013d8d0178503a8abff33d8c4ba5c5 (patch) | |
tree | 63729fab8b1284eef484d870b24dfb30a1e1b022 | |
parent | 3a3c6b7b0387d12b067052e1027cd967fae8378a (diff) |
i2c: i801: Switch to iomapped register access
Switch to iomapped register access as a prerequisite for adding
support for MMIO register access.
This changes replaces the delayed inb_p()/outb_p() calls with calls to
ioread8()/iowrite8() which don't have this extra delay. According to
Documentation/driver-api/device-io.rst the _p versions are needed
for ISA device access only, therefore switching to the non-delayed
versions should not cause problems. However a certain risk remains,
which on the other hand is significantly reduced by the fact that
recent systems will use MMIO instead of PIO. ICH7 datasheet from 2012
mentions already that SMBus register space is also memory-mapped.
So all systems from at least the last 10 yrs should be safe.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/67535b17-c3fb-4507-b083-9c1884b4dd7d@gmail.com
-rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 149 |
1 files changed, 73 insertions, 76 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 6a4147054b49..bf5702ccb93a 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -276,7 +276,7 @@ struct i801_mux_config { struct i801_priv { struct i2c_adapter adapter; - unsigned long smba; + void __iomem *smba; unsigned char original_hstcfg; unsigned char original_hstcnt; unsigned char original_slvcmd; @@ -345,7 +345,7 @@ static int i801_wait_intr(struct i801_priv *priv) do { usleep_range(250, 500); - status = inb_p(SMBHSTSTS(priv)); + status = ioread8(SMBHSTSTS(priv)); busy = status & SMBHSTSTS_HOST_BUSY; status &= STATUS_ERROR_FLAGS | SMBHSTSTS_INTR; if (!busy && status) @@ -363,7 +363,7 @@ static int i801_wait_byte_done(struct i801_priv *priv) do { usleep_range(250, 500); - status = inb_p(SMBHSTSTS(priv)); + status = ioread8(SMBHSTSTS(priv)); if (status & (STATUS_ERROR_FLAGS | SMBHSTSTS_BYTE_DONE)) return status & STATUS_ERROR_FLAGS; } while (time_is_after_eq_jiffies(timeout)); @@ -373,7 +373,7 @@ static int i801_wait_byte_done(struct i801_priv *priv) static int i801_get_block_len(struct i801_priv *priv) { - u8 len = inb_p(SMBHSTDAT0(priv)); + u8 len = ioread8(SMBHSTDAT0(priv)); if (len < 1 || len > I2C_SMBUS_BLOCK_MAX) { pci_err(priv->pci_dev, "Illegal SMBus block read size %u\n", len); @@ -390,9 +390,9 @@ static int i801_check_and_clear_pec_error(struct i801_priv *priv) if (!(priv->features & FEATURE_SMBUS_PEC)) return 0; - status = inb_p(SMBAUXSTS(priv)) & SMBAUXSTS_CRCE; + status = ioread8(SMBAUXSTS(priv)) & SMBAUXSTS_CRCE; if (status) { - outb_p(status, SMBAUXSTS(priv)); + iowrite8(status, SMBAUXSTS(priv)); return -EBADMSG; } @@ -405,7 +405,7 @@ static int i801_check_pre(struct i801_priv *priv) { int status, result; - status = inb_p(SMBHSTSTS(priv)); + status = ioread8(SMBHSTSTS(priv)); if (status & SMBHSTSTS_HOST_BUSY) { pci_err(priv->pci_dev, "SMBus is busy, can't use it!\n"); return -EBUSY; @@ -414,7 +414,7 @@ static int i801_check_pre(struct i801_priv *priv) status &= STATUS_FLAGS; if (status) { pci_dbg(priv->pci_dev, "Clearing status flags (%02x)\n", status); - outb_p(status, SMBHSTSTS(priv)); + iowrite8(status, SMBHSTSTS(priv)); } /* @@ -440,9 +440,9 @@ static int i801_check_post(struct i801_priv *priv, int status) */ if (unlikely(status < 0)) { /* try to stop the current command */ - outb_p(SMBHSTCNT_KILL, SMBHSTCNT(priv)); + iowrite8(SMBHSTCNT_KILL, SMBHSTCNT(priv)); status = i801_wait_intr(priv); - outb_p(0, SMBHSTCNT(priv)); + iowrite8(0, SMBHSTCNT(priv)); /* Check if it worked */ if (status < 0 || !(status & SMBHSTSTS_FAILED)) @@ -493,13 +493,13 @@ static int i801_transaction(struct i801_priv *priv, int xact) if (priv->features & FEATURE_IRQ) { reinit_completion(&priv->done); - outb_p(xact | SMBHSTCNT_INTREN | SMBHSTCNT_START, + iowrite8(xact | SMBHSTCNT_INTREN | SMBHSTCNT_START, SMBHSTCNT(priv)); result = wait_for_completion_timeout(&priv->done, adap->timeout); return result ? priv->status : -ETIMEDOUT; } - outb_p(xact | SMBHSTCNT_START, SMBHSTCNT(priv)); + iowrite8(xact | SMBHSTCNT_START, SMBHSTCNT(priv)); return i801_wait_intr(priv); } @@ -508,7 +508,7 @@ static int i801_block_transaction_by_block(struct i801_priv *priv, union i2c_smbus_data *data, char read_write, int command) { - int i, len, status, xact; + int len, status, xact; switch (command) { case I2C_SMBUS_BLOCK_PROC_CALL: @@ -522,14 +522,13 @@ static int i801_block_transaction_by_block(struct i801_priv *priv, } /* Set block buffer mode */ - outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_E32B, SMBAUXCTL(priv)); + iowrite8(ioread8(SMBAUXCTL(priv)) | SMBAUXCTL_E32B, SMBAUXCTL(priv)); if (read_write == I2C_SMBUS_WRITE) { len = data->block[0]; - outb_p(len, SMBHSTDAT0(priv)); - inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */ - for (i = 0; i < len; i++) - outb_p(data->block[i+1], SMBBLKDAT(priv)); + iowrite8(len, SMBHSTDAT0(priv)); + ioread8(SMBHSTCNT(priv)); /* reset the data buffer index */ + iowrite8_rep(SMBBLKDAT(priv), data->block + 1, len); } status = i801_transaction(priv, xact); @@ -545,12 +544,11 @@ static int i801_block_transaction_by_block(struct i801_priv *priv, } data->block[0] = len; - inb_p(SMBHSTCNT(priv)); /* reset the data buffer index */ - for (i = 0; i < len; i++) - data->block[i + 1] = inb_p(SMBBLKDAT(priv)); + ioread8(SMBHSTCNT(priv)); /* reset the data buffer index */ + ioread8_rep(SMBBLKDAT(priv), data->block + 1, len); } out: - outb_p(inb_p(SMBAUXCTL(priv)) & ~SMBAUXCTL_E32B, SMBAUXCTL(priv)); + iowrite8(ioread8(SMBAUXCTL(priv)) & ~SMBAUXCTL_E32B, SMBAUXCTL(priv)); return status; } @@ -573,17 +571,17 @@ static void i801_isr_byte_done(struct i801_priv *priv) /* Read next byte */ if (priv->count < priv->len) - priv->data[priv->count++] = inb(SMBBLKDAT(priv)); + priv->data[priv->count++] = ioread8(SMBBLKDAT(priv)); else pci_dbg(priv->pci_dev, "Discarding extra byte on block read\n"); /* Set LAST_BYTE for last byte of read transaction */ if (priv->count == priv->len - 1) - outb_p(priv->cmd | SMBHSTCNT_LAST_BYTE, + iowrite8(priv->cmd | SMBHSTCNT_LAST_BYTE, SMBHSTCNT(priv)); } else if (priv->count < priv->len - 1) { /* Write next byte, except for IRQ after last byte */ - outb_p(priv->data[++priv->count], SMBBLKDAT(priv)); + iowrite8(priv->data[++priv->count], SMBBLKDAT(priv)); } } @@ -591,7 +589,7 @@ static irqreturn_t i801_host_notify_isr(struct i801_priv *priv) { unsigned short addr; - addr = inb_p(SMBNTFDADD(priv)) >> 1; + addr = ioread8(SMBNTFDADD(priv)) >> 1; /* * With the tested platforms, reading SMBNTFDDAT (22 + (p)->smba) @@ -601,7 +599,7 @@ static irqreturn_t i801_host_notify_isr(struct i801_priv *priv) i2c_handle_smbus_host_notify(&priv->adapter, addr); /* clear Host Notify bit and return */ - outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv)); + iowrite8(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv)); return IRQ_HANDLED; } @@ -632,12 +630,12 @@ static irqreturn_t i801_isr(int irq, void *dev_id) return IRQ_NONE; if (priv->features & FEATURE_HOST_NOTIFY) { - status = inb_p(SMBSLVSTS(priv)); + status = ioread8(SMBSLVSTS(priv)); if (status & SMBSLVSTS_HST_NTFY_STS) return i801_host_notify_isr(priv); } - status = inb_p(SMBHSTSTS(priv)); + status = ioread8(SMBHSTSTS(priv)); if ((status & (SMBHSTSTS_BYTE_DONE | STATUS_ERROR_FLAGS)) == SMBHSTSTS_BYTE_DONE) i801_isr_byte_done(priv); @@ -647,7 +645,7 @@ static irqreturn_t i801_isr(int irq, void *dev_id) * so clear it always when the status is set. */ status &= STATUS_FLAGS | SMBHSTSTS_SMBALERT_STS; - outb_p(status, SMBHSTSTS(priv)); + iowrite8(status, SMBHSTSTS(priv)); status &= STATUS_ERROR_FLAGS | SMBHSTSTS_INTR; if (status) { @@ -679,8 +677,8 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, len = data->block[0]; if (read_write == I2C_SMBUS_WRITE) { - outb_p(len, SMBHSTDAT0(priv)); - outb_p(data->block[1], SMBBLKDAT(priv)); + iowrite8(len, SMBHSTDAT0(priv)); + iowrite8(data->block[1], SMBBLKDAT(priv)); } if (command == I2C_SMBUS_I2C_BLOCK_DATA && @@ -699,14 +697,14 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, priv->data = &data->block[1]; reinit_completion(&priv->done); - outb_p(priv->cmd | SMBHSTCNT_START, SMBHSTCNT(priv)); + iowrite8(priv->cmd | SMBHSTCNT_START, SMBHSTCNT(priv)); result = wait_for_completion_timeout(&priv->done, adap->timeout); return result ? priv->status : -ETIMEDOUT; } if (len == 1 && read_write == I2C_SMBUS_READ) smbcmd |= SMBHSTCNT_LAST_BYTE; - outb_p(smbcmd | SMBHSTCNT_START, SMBHSTCNT(priv)); + iowrite8(smbcmd | SMBHSTCNT_START, SMBHSTCNT(priv)); for (i = 1; i <= len; i++) { status = i801_wait_byte_done(priv); @@ -722,27 +720,27 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, len = i801_get_block_len(priv); if (len < 0) { /* Recover */ - while (inb_p(SMBHSTSTS(priv)) & + while (ioread8(SMBHSTSTS(priv)) & SMBHSTSTS_HOST_BUSY) - outb_p(SMBHSTSTS_BYTE_DONE, + iowrite8(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv)); - outb_p(SMBHSTSTS_INTR, SMBHSTSTS(priv)); + iowrite8(SMBHSTSTS_INTR, SMBHSTSTS(priv)); return -EPROTO; } data->block[0] = len; } if (read_write == I2C_SMBUS_READ) { - data->block[i] = inb_p(SMBBLKDAT(priv)); + data->block[i] = ioread8(SMBBLKDAT(priv)); if (i == len - 1) - outb_p(smbcmd | SMBHSTCNT_LAST_BYTE, SMBHSTCNT(priv)); + iowrite8(smbcmd | SMBHSTCNT_LAST_BYTE, SMBHSTCNT(priv)); } if (read_write == I2C_SMBUS_WRITE && i+1 <= len) - outb_p(data->block[i+1], SMBBLKDAT(priv)); + iowrite8(data->block[i+1], SMBBLKDAT(priv)); /* signals SMBBLKDAT ready */ - outb_p(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv)); + iowrite8(SMBHSTSTS_BYTE_DONE, SMBHSTSTS(priv)); } return i801_wait_intr(priv); @@ -750,7 +748,7 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, static void i801_set_hstadd(struct i801_priv *priv, u8 addr, char read_write) { - outb_p((addr << 1) | (read_write & 0x01), SMBHSTADD(priv)); + iowrite8((addr << 1) | (read_write & 0x01), SMBHSTADD(priv)); } /* Single value transaction function */ @@ -767,30 +765,30 @@ static int i801_simple_transaction(struct i801_priv *priv, union i2c_smbus_data case I2C_SMBUS_BYTE: i801_set_hstadd(priv, addr, read_write); if (read_write == I2C_SMBUS_WRITE) - outb_p(hstcmd, SMBHSTCMD(priv)); + iowrite8(hstcmd, SMBHSTCMD(priv)); xact = I801_BYTE; break; case I2C_SMBUS_BYTE_DATA: i801_set_hstadd(priv, addr, read_write); if (read_write == I2C_SMBUS_WRITE) - outb_p(data->byte, SMBHSTDAT0(priv)); - outb_p(hstcmd, SMBHSTCMD(priv)); + iowrite8(data->byte, SMBHSTDAT0(priv)); + iowrite8(hstcmd, SMBHSTCMD(priv)); xact = I801_BYTE_DATA; break; case I2C_SMBUS_WORD_DATA: i801_set_hstadd(priv, addr, read_write); if (read_write == I2C_SMBUS_WRITE) { - outb_p(data->word & 0xff, SMBHSTDAT0(priv)); - outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv)); + iowrite8(data->word & 0xff, SMBHSTDAT0(priv)); + iowrite8((data->word & 0xff00) >> 8, SMBHSTDAT1(priv)); } - outb_p(hstcmd, SMBHSTCMD(priv)); + iowrite8(hstcmd, SMBHSTCMD(priv)); xact = I801_WORD_DATA; break; case I2C_SMBUS_PROC_CALL: i801_set_hstadd(priv, addr, I2C_SMBUS_WRITE); - outb_p(data->word & 0xff, SMBHSTDAT0(priv)); - outb_p((data->word & 0xff00) >> 8, SMBHSTDAT1(priv)); - outb_p(hstcmd, SMBHSTCMD(priv)); + iowrite8(data->word & 0xff, SMBHSTDAT0(priv)); + iowrite8((data->word & 0xff00) >> 8, SMBHSTDAT1(priv)); + iowrite8(hstcmd, SMBHSTCMD(priv)); read_write = I2C_SMBUS_READ; xact = I801_PROC_CALL; break; @@ -806,12 +804,12 @@ static int i801_simple_transaction(struct i801_priv *priv, union i2c_smbus_data switch (command) { case I2C_SMBUS_BYTE: case I2C_SMBUS_BYTE_DATA: - data->byte = inb_p(SMBHSTDAT0(priv)); + data->byte = ioread8(SMBHSTDAT0(priv)); break; case I2C_SMBUS_WORD_DATA: case I2C_SMBUS_PROC_CALL: - data->word = inb_p(SMBHSTDAT0(priv)) + - (inb_p(SMBHSTDAT1(priv)) << 8); + data->word = ioread8(SMBHSTDAT0(priv)) + + (ioread8(SMBHSTDAT1(priv)) << 8); break; } @@ -832,7 +830,7 @@ static int i801_smbus_block_transaction(struct i801_priv *priv, union i2c_smbus_ i801_set_hstadd(priv, addr, I2C_SMBUS_WRITE); else i801_set_hstadd(priv, addr, read_write); - outb_p(hstcmd, SMBHSTCMD(priv)); + iowrite8(hstcmd, SMBHSTCMD(priv)); if (priv->features & FEATURE_BLOCK_BUFFER) return i801_block_transaction_by_block(priv, data, read_write, command); @@ -858,9 +856,9 @@ static int i801_i2c_block_transaction(struct i801_priv *priv, union i2c_smbus_da /* NB: page 240 of ICH5 datasheet shows that DATA1 is the cmd field when reading */ if (read_write == I2C_SMBUS_READ) - outb_p(hstcmd, SMBHSTDAT1(priv)); + iowrite8(hstcmd, SMBHSTDAT1(priv)); else - outb_p(hstcmd, SMBHSTCMD(priv)); + iowrite8(hstcmd, SMBHSTCMD(priv)); if (read_write == I2C_SMBUS_WRITE) { /* set I2C_EN bit in configuration register */ @@ -903,9 +901,9 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, && size != I2C_SMBUS_I2C_BLOCK_DATA; if (hwpec) /* enable/disable hardware PEC */ - outb_p(inb_p(SMBAUXCTL(priv)) | SMBAUXCTL_CRC, SMBAUXCTL(priv)); + iowrite8(ioread8(SMBAUXCTL(priv)) | SMBAUXCTL_CRC, SMBAUXCTL(priv)); else - outb_p(inb_p(SMBAUXCTL(priv)) & (~SMBAUXCTL_CRC), + iowrite8(ioread8(SMBAUXCTL(priv)) & (~SMBAUXCTL_CRC), SMBAUXCTL(priv)); if (size == I2C_SMBUS_BLOCK_DATA || size == I2C_SMBUS_BLOCK_PROC_CALL) @@ -921,13 +919,13 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr, * time, so we forcibly disable it after every transaction. */ if (hwpec) - outb_p(inb_p(SMBAUXCTL(priv)) & ~SMBAUXCTL_CRC, SMBAUXCTL(priv)); + iowrite8(ioread8(SMBAUXCTL(priv)) & ~SMBAUXCTL_CRC, SMBAUXCTL(priv)); out: /* * Unlock the SMBus device for use by BIOS/ACPI, * and clear status flags if not done already. */ - outb_p(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv)); + iowrite8(SMBHSTSTS_INUSE_STS | STATUS_FLAGS, SMBHSTSTS(priv)); pm_runtime_mark_last_busy(&priv->pci_dev->dev); pm_runtime_put_autosuspend(&priv->pci_dev->dev); @@ -964,11 +962,11 @@ static void i801_enable_host_notify(struct i2c_adapter *adapter) * from the SMB_ALERT signal because the driver does not support * SMBus Alert. */ - outb_p(SMBSLVCMD_HST_NTFY_INTREN | SMBSLVCMD_SMBALERT_DISABLE | + iowrite8(SMBSLVCMD_HST_NTFY_INTREN | SMBSLVCMD_SMBALERT_DISABLE | priv->original_slvcmd, SMBSLVCMD(priv)); /* clear Host Notify bit to allow a new notification */ - outb_p(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv)); + iowrite8(SMBSLVSTS_HST_NTFY_STS, SMBSLVSTS(priv)); } static void i801_disable_host_notify(struct i801_priv *priv) @@ -976,7 +974,7 @@ static void i801_disable_host_notify(struct i801_priv *priv) if (!(priv->features & FEATURE_HOST_NOTIFY)) return; - outb_p(priv->original_slvcmd, SMBSLVCMD(priv)); + iowrite8(priv->original_slvcmd, SMBSLVCMD(priv)); } static const struct i2c_algorithm smbus_algorithm = { @@ -1441,7 +1439,7 @@ static void i801_add_tco(struct i801_priv *priv) static bool i801_acpi_is_smbus_ioport(const struct i801_priv *priv, acpi_physical_address address) { - return address >= priv->smba && + return address >= pci_resource_start(priv->pci_dev, SMBBAR) && address <= pci_resource_end(priv->pci_dev, SMBBAR); } @@ -1518,7 +1516,7 @@ static void i801_setup_hstcfg(struct i801_priv *priv) static void i801_restore_regs(struct i801_priv *priv) { - outb_p(priv->original_hstcnt, SMBHSTCNT(priv)); + iowrite8(priv->original_hstcnt, SMBHSTCNT(priv)); pci_write_config_byte(priv->pci_dev, SMBHSTCFG, priv->original_hstcfg); } @@ -1564,8 +1562,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) } /* Determine the address of the SMBus area */ - priv->smba = pci_resource_start(dev, SMBBAR); - if (!priv->smba) { + if (!pci_resource_start(dev, SMBBAR)) { pci_err(dev, "SMBus base address uninitialized, upgrade BIOS\n"); return -ENODEV; } @@ -1573,12 +1570,12 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) if (i801_acpi_probe(priv)) return -ENODEV; - err = pcim_iomap_regions(dev, 1 << SMBBAR, DRV_NAME); - if (err) { + priv->smba = pcim_iomap_region(dev, SMBBAR, DRV_NAME); + if (IS_ERR(priv->smba)) { pci_err(dev, "Failed to request SMBus region %pr\n", pci_resource_n(dev, SMBBAR)); i801_acpi_remove(priv); - return err; + return PTR_ERR(priv->smba); } pci_read_config_byte(dev, SMBHSTCFG, &priv->original_hstcfg); @@ -1596,7 +1593,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) /* Clear special mode bits */ if (priv->features & (FEATURE_SMBUS_PEC | FEATURE_BLOCK_BUFFER)) - outb_p(inb_p(SMBAUXCTL(priv)) & + iowrite8(ioread8(SMBAUXCTL(priv)) & ~(SMBAUXCTL_CRC | SMBAUXCTL_E32B), SMBAUXCTL(priv)); /* Default timeout in interrupt mode: 200 ms */ @@ -1632,9 +1629,9 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) priv->features &= ~FEATURE_HOST_NOTIFY; /* Remember original Interrupt and Host Notify settings */ - priv->original_hstcnt = inb_p(SMBHSTCNT(priv)) & ~SMBHSTCNT_KILL; + priv->original_hstcnt = ioread8(SMBHSTCNT(priv)) & ~SMBHSTCNT_KILL; if (priv->features & FEATURE_HOST_NOTIFY) - priv->original_slvcmd = inb_p(SMBSLVCMD(priv)); + priv->original_slvcmd = ioread8(SMBSLVCMD(priv)); i801_add_tco(priv); @@ -1643,9 +1640,9 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id) * to instantiante i2c_clients, do not change. */ snprintf(priv->adapter.name, sizeof(priv->adapter.name), - "SMBus %s adapter at %04lx", + "SMBus %s adapter at %s", (priv->features & FEATURE_IDF) ? "I801 IDF" : "I801", - priv->smba); + pci_name(dev)); err = i2c_add_adapter(&priv->adapter); if (err) { |