> +config I2C_XLR > + tristate "XLR I2C support" > + depends on CPU_XLR > + help > + This driver enables support for the on-chip I2C interface of > + the Netlogic XLR/XLS MIPS processors. > + > + Say yes to this option if you have a Netlogic XLR/XLS based > + board and you need to access the I2C devices (typically the > + RTC, sensors, EEPROM) connected to this interface.
Do you insist on this paragraph? > + > + This driver can also be built as a module. If so, the module > + will be called i2c-xlr. > + > config I2C_EG20T > tristate "Intel EG20T PCH / OKI SEMICONDUCTOR IOH(ML7213/ML7223)" > depends on PCI > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index fba6da6..4372dee 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -68,6 +68,7 @@ obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o > obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o > obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o > obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o > +obj-$(CONFIG_I2C_XLR) += i2c-xlr.o Use tabs here. > obj-$(CONFIG_I2C_EG20T) += i2c-eg20t.o > > # External I2C/SMBus adapter drivers > diff --git a/drivers/i2c/busses/i2c-xlr.c b/drivers/i2c/busses/i2c-xlr.c > new file mode 100644 > index 0000000..62307ba > --- /dev/null > +++ b/drivers/i2c/busses/i2c-xlr.c > @@ -0,0 +1,285 @@ > +/* > + * Copyright 2011, Netlogic Microsystems Inc. > + * Copyright 2004, Matt Porter <[email protected]> > + * > + * This file is licensed under the terms of the GNU General Public > + * License version 2. This program is licensed "as is" without any > + * warranty of any kind, whether express or implied. > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/slab.h> > +#include <linux/init.h> > +#include <linux/ioport.h> > +#include <linux/delay.h> > +#include <linux/errno.h> > +#include <linux/i2c.h> > +#include <linux/io.h> > +#include <linux/platform_device.h> > + > +/* XLR I2C REGISTERS */ > +#define XLR_I2C_CFG 0x00 > +#define XLR_I2C_CLKDIV 0x01 > +#define XLR_I2C_DEVADDR 0x02 > +#define XLR_I2C_ADDR 0x03 > +#define XLR_I2C_DATAOUT 0x04 > +#define XLR_I2C_DATAIN 0x05 > +#define XLR_I2C_STATUS 0x06 > +#define XLR_I2C_STARTXFR 0x07 > +#define XLR_I2C_BYTECNT 0x08 > +#define XLR_I2C_HDSTATIM 0x09 > + > +/* XLR I2C REGISTERS FLAGS */ > +#define XLR_I2C_BUS_BUSY 0x01 > +#define XLR_I2C_SDOEMPTY 0x02 > +#define XLR_I2C_RXRDY 0x04 > +#define XLR_I2C_ACK_ERR 0x08 > +#define XLR_I2C_ARB_STARTERR 0x30 > + > +/* Register Values */ > +#define XLR_I2C_CFG_ADDR 0xF8 > +#define XLR_I2C_CFG_NOADDR 0xFA > +#define XLR_I2C_STARTXFR_ND 0x02 /* No Data */ > +#define XLR_I2C_STARTXFR_RD 0x01 /* Read */ > +#define XLR_I2C_STARTXFR_WR 0x00 /* Write */ > + > +#define MAX_RETRIES 5000 /* max retries per byte */ > + > +/* > + * On XLR/XLS, we need to use __raw_ IO to read the I2C registers > + * because they are in the big-endian MMIO area on the SoC. > + * > + * The readl/writel implementation on XLR/XLS byteswaps, beacause > + * those are for its little-endian PCI space (see arch/mips/Kconfig). > + */ Good, thanks. > +static inline void xlr_i2c_wreg(u32 __iomem *base, unsigned int reg, u32 val) > +{ > + __raw_writel(val, base + reg); > +} > + > +static inline u32 xlr_i2c_rdreg(u32 __iomem *base, unsigned int reg) > +{ > + return __raw_readl(base + reg); > +} > + > +struct xlr_i2c_private { > + struct i2c_adapter adap; > + u32 __iomem *iobase; > +}; > + > +static int xlr_i2c_tx(struct xlr_i2c_private *priv, u16 len, > + u8 *buf, u16 addr) > +{ > + struct i2c_adapter *adap = &priv->adap; > + u32 i2c_status; > + int pos, retries; > + u8 offset, nb; > + > + offset = buf[0]; > + xlr_i2c_wreg(priv->iobase, XLR_I2C_ADDR, offset); > + xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr); > + xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_ADDR); > + xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1); > + > + retries = 0; > +retry: > + pos = 1; > + if (len == 1) { > + xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, > + XLR_I2C_STARTXFR_ND); > + } else { > + xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[pos]); > + xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, > + XLR_I2C_STARTXFR_WR); > + } > + > + while (1) { > + if (retries++ > MAX_RETRIES) { > + dev_err(&adap->dev, "I2C transmit timeout\n"); > + return -ETIMEDOUT; > + } Still no. A device usually fails after trying for a specific period of time, not after a number of retries. You need to work with jiffies here and time_after/time_before. Check drivers/misc/eeprom/at24.c for an example. Or check the second part of my talk from Prague :) http://free-electrons.com/blog/elce-2011-videos/ > + > + i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS); > + > + if (i2c_status & XLR_I2C_SDOEMPTY) { > + pos++; > + retries = 0; > + nb = (pos < len) ? buf[pos] : 0; > + xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, nb); > + } > + > + if (i2c_status & XLR_I2C_ARB_STARTERR) > + goto retry; This will be an endless loop if the STARTERR condition remains? Also this goto jumping out of the while loop is not nice. It might help to rearrange the loops. > + > + if (i2c_status & XLR_I2C_ACK_ERR) > + return -EIO; > + > + if (i2c_status & XLR_I2C_BUS_BUSY) { > + udelay(1); > + continue; > + } > + > + if (pos >= len) > + break; > + } > + > + return 0; > +} > + > +static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 > addr) > +{ > + struct i2c_adapter *adap = &priv->adap; > + u32 i2c_status; > + int pos, retries; > + > + xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_NOADDR); > + xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len); > + xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr); > + > + retries = 0; > + pos = 0; > +retry: > + xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_RD); > + > + while (1) { > + if (retries++ > MAX_RETRIES) { > + dev_err(&adap->dev, "I2C receive timeout\n"); > + return -ETIMEDOUT; > + } > + > + i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS); > + if (i2c_status & XLR_I2C_RXRDY) { > + buf[pos++] = (u8)xlr_i2c_rdreg(priv->iobase, > + XLR_I2C_DATAIN); > + retries = 0; > + } comments from above also here. > + > + if (i2c_status & XLR_I2C_ARB_STARTERR) > + goto retry; > + > + if (i2c_status & XLR_I2C_ACK_ERR) { > + dev_err(&adap->dev, "I2C receive ACK error\n"); > + return -EIO; > + } > + > + if ((i2c_status & XLR_I2C_BUS_BUSY) == 0) > + break; > + udelay(1); > + } > + return 0; > +} > + > +static int xlr_i2c_xfer(struct i2c_adapter *adap, > + struct i2c_msg *msgs, int num) > +{ > + struct i2c_msg *msg; > + int i; > + int ret = 0; > + struct xlr_i2c_private *priv = i2c_get_adapdata(adap); > + > + for (i = 0; ret == 0 && i < num; i++) { > + msg = &msgs[i]; > + if (msg->flags & I2C_M_RD) > + ret = xlr_i2c_rx(priv, msg->len, &msg->buf[0], > + msg->addr); > + else > + ret = xlr_i2c_tx(priv, msg->len, &msg->buf[0], > + msg->addr); > + } > + > + return (ret != 0) ? ret : num; > +} > + > +static u32 xlr_func(struct i2c_adapter *adap) > +{ > + /* Emulate SMBUS over I2C */ > + return I2C_FUNC_SMBUS_EMUL | I2C_FUNC_I2C; > +} > + > +static struct i2c_algorithm xlr_i2c_algo = { > + .master_xfer = xlr_i2c_xfer, > + .functionality = xlr_func, > +}; > + > +static int __devinit xlr_i2c_probe(struct platform_device *pdev) > +{ > + struct xlr_i2c_private *priv; > + struct resource *res; > + int ret; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (!res) > + return -ENXIO; You don't have to check res, devm_request_and_ioremap() will do it for you. > + > + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->iobase = devm_request_and_ioremap(&pdev->dev, res); > + if (!priv->iobase) { > + dev_err(&pdev->dev, "devm_request_and_ioremap failed\n"); > + ret = -EBUSY; > + goto err1; > + } > + > + priv->adap.dev.parent = &pdev->dev; > + priv->adap.owner = THIS_MODULE; > + priv->adap.algo_data = priv; > + priv->adap.algo = &xlr_i2c_algo; > + priv->adap.nr = pdev->id; > + priv->adap.class = I2C_CLASS_HWMON; > + snprintf(priv->adap.name, sizeof(priv->adap.name), "xlr-i2c"); > + > + platform_set_drvdata(pdev, priv); > + i2c_set_adapdata(&priv->adap, priv); > + ret = i2c_add_numbered_adapter(&priv->adap); > + > + if (ret < 0) { > + dev_err(&priv->adap.dev, "Failed to add i2c bus.\n"); > + goto err2; > + } > + > + dev_info(&priv->adap.dev, "Added I2C Bus.\n"); > + return 0; > +err2: > + devm_release_mem_region(&pdev->dev, res->start, resource_size(res)); > + devm_iounmap(&pdev->dev, priv->iobase); You don't need to free devm_* resources. That's the main point of it :) > + platform_set_drvdata(pdev, NULL); > +err1: > + devm_kfree(&pdev->dev, priv); > + return ret; > +} > + > +static int __devexit xlr_i2c_remove(struct platform_device *pdev) > +{ > + struct xlr_i2c_private *priv; > + struct resource *res; > + > + priv = platform_get_drvdata(pdev); > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + > + i2c_del_adapter(&priv->adap); > + devm_release_mem_region(&pdev->dev, res->start, resource_size(res)); > + devm_iounmap(&pdev->dev, priv->iobase); > + devm_kfree(&pdev->dev, priv); > + > + platform_set_drvdata(pdev, NULL); > + return 0; > +} > + > +static struct platform_driver xlr_i2c_driver = { > + .probe = xlr_i2c_probe, > + .remove = __devexit_p(xlr_i2c_remove), > + .driver = { > + .name = "xlr-i2cbus", > + .owner = THIS_MODULE, > + }, > +}; > + > +module_platform_driver(xlr_i2c_driver); > + > +MODULE_AUTHOR("Ganesan Ramalingam <[email protected]>"); > +MODULE_DESCRIPTION("XLR/XLS SoC I2C Controller driver"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("platform:xlr-i2cbus"); > -- > 1.7.5.4 > -- Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ |
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