From 03dd4cb26d967f9588437b0fc9cc0e8353322bb7 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Fri, 25 Mar 2016 03:53:42 -0300 Subject: Linux-libre 4.5-gnu --- drivers/i2c/busses/i2c-xlr.c | 250 ++++++++++++++++++++++++++++++++++++++----- 1 file changed, 223 insertions(+), 27 deletions(-) (limited to 'drivers/i2c/busses/i2c-xlr.c') diff --git a/drivers/i2c/busses/i2c-xlr.c b/drivers/i2c/busses/i2c-xlr.c index 8b36bcfd9..613c3a4f2 100644 --- a/drivers/i2c/busses/i2c-xlr.c +++ b/drivers/i2c/busses/i2c-xlr.c @@ -17,6 +17,10 @@ #include #include #include +#include +#include +#include +#include /* XLR I2C REGISTERS */ #define XLR_I2C_CFG 0x00 @@ -30,6 +34,10 @@ #define XLR_I2C_BYTECNT 0x08 #define XLR_I2C_HDSTATIM 0x09 +/* Sigma Designs additional registers */ +#define XLR_I2C_INT_EN 0x09 +#define XLR_I2C_INT_STAT 0x0a + /* XLR I2C REGISTERS FLAGS */ #define XLR_I2C_BUS_BUSY 0x01 #define XLR_I2C_SDOEMPTY 0x02 @@ -63,11 +71,98 @@ static inline u32 xlr_i2c_rdreg(u32 __iomem *base, unsigned int reg) return __raw_readl(base + reg); } +#define XLR_I2C_FLAG_IRQ 1 + +struct xlr_i2c_config { + u32 flags; /* optional feature support */ + u32 status_busy; /* value of STATUS[0] when busy */ + u32 cfg_extra; /* extra CFG bits to set */ +}; + struct xlr_i2c_private { struct i2c_adapter adap; u32 __iomem *iobase; + int irq; + int pos; + struct i2c_msg *msg; + const struct xlr_i2c_config *cfg; + wait_queue_head_t wait; + struct clk *clk; }; +static int xlr_i2c_busy(struct xlr_i2c_private *priv, u32 status) +{ + return (status & XLR_I2C_BUS_BUSY) == priv->cfg->status_busy; +} + +static int xlr_i2c_idle(struct xlr_i2c_private *priv) +{ + return !xlr_i2c_busy(priv, xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS)); +} + +static int xlr_i2c_wait(struct xlr_i2c_private *priv, unsigned long timeout) +{ + int status; + int t; + + t = wait_event_timeout(priv->wait, xlr_i2c_idle(priv), + msecs_to_jiffies(timeout)); + if (!t) + return -ETIMEDOUT; + + status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS); + + return status & XLR_I2C_ACK_ERR ? -EIO : 0; +} + +static void xlr_i2c_tx_irq(struct xlr_i2c_private *priv, u32 status) +{ + struct i2c_msg *msg = priv->msg; + + if (status & XLR_I2C_SDOEMPTY) + xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, + msg->buf[priv->pos++]); +} + +static void xlr_i2c_rx_irq(struct xlr_i2c_private *priv, u32 status) +{ + struct i2c_msg *msg = priv->msg; + + if (status & XLR_I2C_RXRDY) + msg->buf[priv->pos++] = + xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN); +} + +static irqreturn_t xlr_i2c_irq(int irq, void *dev_id) +{ + struct xlr_i2c_private *priv = dev_id; + struct i2c_msg *msg = priv->msg; + u32 int_stat, status; + + int_stat = xlr_i2c_rdreg(priv->iobase, XLR_I2C_INT_STAT); + if (!int_stat) + return IRQ_NONE; + + xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_STAT, int_stat); + + if (!msg) + return IRQ_HANDLED; + + status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS); + + if (priv->pos < msg->len) { + if (msg->flags & I2C_M_RD) + xlr_i2c_rx_irq(priv, status); + else + xlr_i2c_tx_irq(priv, status); + } + + if (!xlr_i2c_busy(priv, status)) + wake_up(&priv->wait); + + return IRQ_HANDLED; +} + static int xlr_i2c_tx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 addr) { @@ -75,37 +170,48 @@ static int xlr_i2c_tx(struct xlr_i2c_private *priv, u16 len, unsigned long timeout, stoptime, checktime; u32 i2c_status; int pos, timedout; - u8 offset, byte; + u8 offset; + u32 xfer; + + if (!len) + return -EOPNOTSUPP; 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); + xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, + XLR_I2C_CFG_ADDR | priv->cfg->cfg_extra); timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT); stoptime = jiffies + timeout; timedout = 0; - pos = 1; -retry: + if (len == 1) { - xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, - XLR_I2C_STARTXFR_ND); + xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1); + xfer = XLR_I2C_STARTXFR_ND; + pos = 1; } else { - xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[pos]); - xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, - XLR_I2C_STARTXFR_WR); + xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 2); + xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[1]); + xfer = XLR_I2C_STARTXFR_WR; + pos = 2; } + priv->pos = pos; + +retry: + /* retry can only happen on the first byte */ + xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, xfer); + + if (priv->irq > 0) + return xlr_i2c_wait(priv, XLR_I2C_TIMEOUT * len); + while (!timedout) { checktime = jiffies; i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS); - if (i2c_status & XLR_I2C_SDOEMPTY) { - pos++; - /* need to do a empty dataout after the last byte */ - byte = (pos < len) ? buf[pos] : 0; - xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, byte); + if ((i2c_status & XLR_I2C_SDOEMPTY) && pos < len) { + xlr_i2c_wreg(priv->iobase, XLR_I2C_DATAOUT, buf[pos++]); /* reset timeout on successful xmit */ stoptime = jiffies + timeout; @@ -121,7 +227,7 @@ retry: if (i2c_status & XLR_I2C_ACK_ERR) return -EIO; - if ((i2c_status & XLR_I2C_BUS_BUSY) == 0 && pos >= len) + if (!xlr_i2c_busy(priv, i2c_status) && pos >= len) return 0; } dev_err(&adap->dev, "I2C transmit timeout\n"); @@ -134,12 +240,17 @@ static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 addr) u32 i2c_status; unsigned long timeout, stoptime, checktime; int nbytes, timedout; - u8 byte; - xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, XLR_I2C_CFG_NOADDR); - xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len); + if (!len) + return -EOPNOTSUPP; + + xlr_i2c_wreg(priv->iobase, XLR_I2C_CFG, + XLR_I2C_CFG_NOADDR | priv->cfg->cfg_extra); + xlr_i2c_wreg(priv->iobase, XLR_I2C_BYTECNT, len - 1); xlr_i2c_wreg(priv->iobase, XLR_I2C_DEVADDR, addr); + priv->pos = 0; + timeout = msecs_to_jiffies(XLR_I2C_TIMEOUT); stoptime = jiffies + timeout; timedout = 0; @@ -147,18 +258,18 @@ static int xlr_i2c_rx(struct xlr_i2c_private *priv, u16 len, u8 *buf, u16 addr) retry: xlr_i2c_wreg(priv->iobase, XLR_I2C_STARTXFR, XLR_I2C_STARTXFR_RD); + if (priv->irq > 0) + return xlr_i2c_wait(priv, XLR_I2C_TIMEOUT * len); + while (!timedout) { checktime = jiffies; i2c_status = xlr_i2c_rdreg(priv->iobase, XLR_I2C_STATUS); if (i2c_status & XLR_I2C_RXRDY) { - if (nbytes > len) + if (nbytes >= len) return -EIO; /* should not happen */ - /* we need to do a dummy datain when nbytes == len */ - byte = xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN); - if (nbytes < len) - buf[nbytes] = byte; - nbytes++; + buf[nbytes++] = + xlr_i2c_rdreg(priv->iobase, XLR_I2C_DATAIN); /* reset timeout on successful read */ stoptime = jiffies + timeout; @@ -174,7 +285,7 @@ retry: if (i2c_status & XLR_I2C_ACK_ERR) return -EIO; - if ((i2c_status & XLR_I2C_BUS_BUSY) == 0) + if (!xlr_i2c_busy(priv, i2c_status)) return 0; } @@ -190,8 +301,17 @@ static int xlr_i2c_xfer(struct i2c_adapter *adap, int ret = 0; struct xlr_i2c_private *priv = i2c_get_adapdata(adap); + ret = clk_enable(priv->clk); + if (ret) + return ret; + + if (priv->irq) + xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0xf); + + for (i = 0; ret == 0 && i < num; i++) { msg = &msgs[i]; + priv->msg = msg; if (msg->flags & I2C_M_RD) ret = xlr_i2c_rx(priv, msg->len, &msg->buf[0], msg->addr); @@ -200,13 +320,19 @@ static int xlr_i2c_xfer(struct i2c_adapter *adap, msg->addr); } + if (priv->irq) + xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0); + + clk_disable(priv->clk); + priv->msg = NULL; + 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; + return (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | I2C_FUNC_I2C; } static struct i2c_algorithm xlr_i2c_algo = { @@ -214,22 +340,89 @@ static struct i2c_algorithm xlr_i2c_algo = { .functionality = xlr_func, }; +static const struct xlr_i2c_config xlr_i2c_config_default = { + .status_busy = XLR_I2C_BUS_BUSY, + .cfg_extra = 0, +}; + +static const struct xlr_i2c_config xlr_i2c_config_tangox = { + .flags = XLR_I2C_FLAG_IRQ, + .status_busy = 0, + .cfg_extra = 1 << 8, +}; + +static const struct of_device_id xlr_i2c_dt_ids[] = { + { + .compatible = "sigma,smp8642-i2c", + .data = &xlr_i2c_config_tangox, + }, + { } +}; + static int xlr_i2c_probe(struct platform_device *pdev) { + const struct of_device_id *match; struct xlr_i2c_private *priv; struct resource *res; + struct clk *clk; + unsigned long clk_rate; + unsigned long clk_div; + u32 busfreq; + int irq; int ret; priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); if (!priv) return -ENOMEM; + match = of_match_device(xlr_i2c_dt_ids, &pdev->dev); + if (match) + priv->cfg = match->data; + else + priv->cfg = &xlr_i2c_config_default; + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); priv->iobase = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(priv->iobase)) return PTR_ERR(priv->iobase); + irq = platform_get_irq(pdev, 0); + + if (irq > 0 && (priv->cfg->flags & XLR_I2C_FLAG_IRQ)) { + priv->irq = irq; + + xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_EN, 0); + xlr_i2c_wreg(priv->iobase, XLR_I2C_INT_STAT, 0xf); + + ret = devm_request_irq(&pdev->dev, priv->irq, xlr_i2c_irq, + IRQF_SHARED, dev_name(&pdev->dev), + priv); + if (ret) + return ret; + + init_waitqueue_head(&priv->wait); + } + + if (of_property_read_u32(pdev->dev.of_node, "clock-frequency", + &busfreq)) + busfreq = 100000; + + clk = devm_clk_get(&pdev->dev, NULL); + if (!IS_ERR(clk)) { + ret = clk_prepare_enable(clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(clk); + clk_div = DIV_ROUND_UP(clk_rate, 2 * busfreq); + xlr_i2c_wreg(priv->iobase, XLR_I2C_CLKDIV, clk_div); + + clk_disable(clk); + priv->clk = clk; + } + priv->adap.dev.parent = &pdev->dev; + priv->adap.dev.of_node = pdev->dev.of_node; priv->adap.owner = THIS_MODULE; priv->adap.algo_data = priv; priv->adap.algo = &xlr_i2c_algo; @@ -255,6 +448,8 @@ static int xlr_i2c_remove(struct platform_device *pdev) priv = platform_get_drvdata(pdev); i2c_del_adapter(&priv->adap); + clk_unprepare(priv->clk); + return 0; } @@ -263,6 +458,7 @@ static struct platform_driver xlr_i2c_driver = { .remove = xlr_i2c_remove, .driver = { .name = "xlr-i2cbus", + .of_match_table = xlr_i2c_dt_ids, }, }; -- cgit v1.2.3-54-g00ecf