From 82fa63bd6b87969dfde0139dbede243380b087d6 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Fri, 12 Oct 2012 11:55:16 +0100 Subject: i2c: mxs: remove broken PIOQUEUE support This I2C master can do DMA and PIOQUEUE (PIO with FIFO). Originally, only PIOQUEUE was supported and it had issues, then DMA support was added this cycle. The original intention was to keep PIOQUEUE since it has less overhead what is nice for small transfers. However, runtime switching between PIOQEUE and DMA depending on the transfer size never worked despite a lot of trying. Since PIOQUEUE mode itself was flaky (polling at places where interrupts failed to work) and the implementation also imposed a size limit for transfers, it is best to remove the support, so users don't fall over its limitations. It also makes the driver a lot cleaner and more robust. If somebody really wants less overhead, plain PIO mode could still be implemented with the addidtional advantage that this mode is also available on MX23, too. Signed-off-by: Wolfram Sang Reviewed-by: Marek Vasut --- drivers/i2c/busses/i2c-mxs.c | 186 ++++--------------------------------------- 1 file changed, 14 insertions(+), 172 deletions(-) diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 1f58197..286ca19 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -1,7 +1,7 @@ /* * Freescale MXS I2C bus driver * - * Copyright (C) 2011 Wolfram Sang, Pengutronix e.K. + * Copyright (C) 2011-2012 Wolfram Sang, Pengutronix e.K. * * based on a (non-working) driver which was: * @@ -35,10 +35,6 @@ #define DRIVER_NAME "mxs-i2c" -static bool use_pioqueue; -module_param(use_pioqueue, bool, 0); -MODULE_PARM_DESC(use_pioqueue, "Use PIOQUEUE mode for transfer instead of DMA"); - #define MXS_I2C_CTRL0 (0x00) #define MXS_I2C_CTRL0_SET (0x04) @@ -75,23 +71,6 @@ MODULE_PARM_DESC(use_pioqueue, "Use PIOQUEUE mode for transfer instead of DMA"); MXS_I2C_CTRL1_SLAVE_STOP_IRQ | \ MXS_I2C_CTRL1_SLAVE_IRQ) -#define MXS_I2C_QUEUECTRL (0x60) -#define MXS_I2C_QUEUECTRL_SET (0x64) -#define MXS_I2C_QUEUECTRL_CLR (0x68) - -#define MXS_I2C_QUEUECTRL_QUEUE_RUN 0x20 -#define MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE 0x04 - -#define MXS_I2C_QUEUESTAT (0x70) -#define MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY 0x00002000 -#define MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK 0x0000001F - -#define MXS_I2C_QUEUECMD (0x80) - -#define MXS_I2C_QUEUEDATA (0x90) - -#define MXS_I2C_DATA (0xa0) - #define MXS_CMD_I2C_SELECT (MXS_I2C_CTRL0_RETAIN_CLOCK | \ MXS_I2C_CTRL0_PRE_SEND_START | \ @@ -153,7 +132,6 @@ struct mxs_i2c_dev { const struct mxs_i2c_speed_config *speed; /* DMA support components */ - bool dma_mode; int dma_channel; struct dma_chan *dmach; struct mxs_dma_data dma_data; @@ -172,99 +150,6 @@ static void mxs_i2c_reset(struct mxs_i2c_dev *i2c) writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2); writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET); - if (i2c->dma_mode) - writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, - i2c->regs + MXS_I2C_QUEUECTRL_CLR); - else - writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, - i2c->regs + MXS_I2C_QUEUECTRL_SET); -} - -static void mxs_i2c_pioq_setup_read(struct mxs_i2c_dev *i2c, u8 addr, int len, - int flags) -{ - u32 data; - - writel(MXS_CMD_I2C_SELECT, i2c->regs + MXS_I2C_QUEUECMD); - - data = (addr << 1) | I2C_SMBUS_READ; - writel(data, i2c->regs + MXS_I2C_DATA); - - data = MXS_CMD_I2C_READ | MXS_I2C_CTRL0_XFER_COUNT(len) | flags; - writel(data, i2c->regs + MXS_I2C_QUEUECMD); -} - -static void mxs_i2c_pioq_setup_write(struct mxs_i2c_dev *i2c, - u8 addr, u8 *buf, int len, int flags) -{ - u32 data; - int i, shifts_left; - - data = MXS_CMD_I2C_WRITE | MXS_I2C_CTRL0_XFER_COUNT(len + 1) | flags; - writel(data, i2c->regs + MXS_I2C_QUEUECMD); - - /* - * We have to copy the slave address (u8) and buffer (arbitrary number - * of u8) into the data register (u32). To achieve that, the u8 are put - * into the MSBs of 'data' which is then shifted for the next u8. When - * appropriate, 'data' is written to MXS_I2C_DATA. So, the first u32 - * looks like this: - * - * 3 2 1 0 - * 10987654|32109876|54321098|76543210 - * --------+--------+--------+-------- - * buffer+2|buffer+1|buffer+0|slave_addr - */ - - data = ((addr << 1) | I2C_SMBUS_WRITE) << 24; - - for (i = 0; i < len; i++) { - data >>= 8; - data |= buf[i] << 24; - if ((i & 3) == 2) - writel(data, i2c->regs + MXS_I2C_DATA); - } - - /* Write out the remaining bytes if any */ - shifts_left = 24 - (i & 3) * 8; - if (shifts_left) - writel(data >> shifts_left, i2c->regs + MXS_I2C_DATA); -} - -/* - * TODO: should be replaceable with a waitqueue and RD_QUEUE_IRQ (setting the - * rd_threshold to 1). Couldn't get this to work, though. - */ -static int mxs_i2c_wait_for_data(struct mxs_i2c_dev *i2c) -{ - unsigned long timeout = jiffies + msecs_to_jiffies(1000); - - while (readl(i2c->regs + MXS_I2C_QUEUESTAT) - & MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY) { - if (time_after(jiffies, timeout)) - return -ETIMEDOUT; - cond_resched(); - } - - return 0; -} - -static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len) -{ - u32 uninitialized_var(data); - int i; - - for (i = 0; i < len; i++) { - if ((i & 3) == 0) { - if (mxs_i2c_wait_for_data(i2c)) - return -ETIMEDOUT; - data = readl(i2c->regs + MXS_I2C_QUEUEDATA); - } - buf[i] = data & 0xff; - data >>= 8; - } - - return 0; } static void mxs_i2c_dma_finish(struct mxs_i2c_dev *i2c) @@ -432,39 +317,17 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, init_completion(&i2c->cmd_complete); i2c->cmd_err = 0; - if (i2c->dma_mode) { - ret = mxs_i2c_dma_setup_xfer(adap, msg, flags); - if (ret) - return ret; - } else { - if (msg->flags & I2C_M_RD) { - mxs_i2c_pioq_setup_read(i2c, msg->addr, - msg->len, flags); - } else { - mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf, - msg->len, flags); - } - - writel(MXS_I2C_QUEUECTRL_QUEUE_RUN, - i2c->regs + MXS_I2C_QUEUECTRL_SET); - } + ret = mxs_i2c_dma_setup_xfer(adap, msg, flags); + if (ret) + return ret; ret = wait_for_completion_timeout(&i2c->cmd_complete, msecs_to_jiffies(1000)); if (ret == 0) goto timeout; - if (!i2c->dma_mode && !i2c->cmd_err && (msg->flags & I2C_M_RD)) { - ret = mxs_i2c_finish_read(i2c, msg->buf, msg->len); - if (ret) - goto timeout; - } - if (i2c->cmd_err == -ENXIO) mxs_i2c_reset(i2c); - else - writel(MXS_I2C_QUEUECTRL_QUEUE_RUN, - i2c->regs + MXS_I2C_QUEUECTRL_CLR); dev_dbg(i2c->dev, "Done with err=%d\n", i2c->cmd_err); @@ -472,8 +335,7 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, timeout: dev_dbg(i2c->dev, "Timeout!\n"); - if (i2c->dma_mode) - mxs_i2c_dma_finish(i2c); + mxs_i2c_dma_finish(i2c); mxs_i2c_reset(i2c); return -ETIMEDOUT; } @@ -502,7 +364,6 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id) { struct mxs_i2c_dev *i2c = dev_id; u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK; - bool is_last_cmd; if (!stat) return IRQ_NONE; @@ -515,14 +376,6 @@ static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id) /* MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ is only for slaves */ i2c->cmd_err = -EIO; - if (!i2c->dma_mode) { - is_last_cmd = (readl(i2c->regs + MXS_I2C_QUEUESTAT) & - MXS_I2C_QUEUESTAT_WRITE_QUEUE_CNT_MASK) == 0; - - if (is_last_cmd || i2c->cmd_err) - complete(&i2c->cmd_complete); - } - writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR); return IRQ_HANDLED; @@ -556,23 +409,14 @@ static int mxs_i2c_get_ofdata(struct mxs_i2c_dev *i2c) int ret; /* - * The MXS I2C DMA mode is prefered and enabled by default. - * The PIO mode is still supported, but should be used only - * for debuging purposes etc. - */ - i2c->dma_mode = !use_pioqueue; - if (!i2c->dma_mode) - dev_info(dev, "Using PIOQUEUE mode for I2C transfers!\n"); - - /* * TODO: This is a temporary solution and should be changed * to use generic DMA binding later when the helpers get in. */ ret = of_property_read_u32(node, "fsl,i2c-dma-channel", &i2c->dma_channel); if (ret) { - dev_warn(dev, "Failed to get DMA channel, using PIOQUEUE!\n"); - i2c->dma_mode = 0; + dev_err(dev, "Failed to get DMA channel!\n"); + return -ENODEV; } ret = of_property_read_u32(node, "clock-frequency", &speed); @@ -634,15 +478,13 @@ static int __devinit mxs_i2c_probe(struct platform_device *pdev) } /* Setup the DMA */ - if (i2c->dma_mode) { - dma_cap_zero(mask); - dma_cap_set(DMA_SLAVE, mask); - i2c->dma_data.chan_irq = dmairq; - i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c); - if (!i2c->dmach) { - dev_err(dev, "Failed to request dma\n"); - return -ENODEV; - } + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + i2c->dma_data.chan_irq = dmairq; + i2c->dmach = dma_request_channel(mask, mxs_i2c_dma_filter, i2c); + if (!i2c->dmach) { + dev_err(dev, "Failed to request dma\n"); + return -ENODEV; } platform_set_drvdata(pdev, i2c); -- cgit v1.1 From 817315f57408b1a9c78cbc7ff2bf186da45ddcc1 Mon Sep 17 00:00:00 2001 From: Philippe Begnic Date: Wed, 10 Oct 2012 13:02:26 +0200 Subject: i2c-nomadik: Fixup clock handling Make sure to clk_prepare as well as clk_enable. Signed-off-by: Philippe Begnic Signed-off-by: Ulf Hansson Signed-off-by: Linus Walleij Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-nomadik.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c index 698d7ac..02c3115 100644 --- a/drivers/i2c/busses/i2c-nomadik.c +++ b/drivers/i2c/busses/i2c-nomadik.c @@ -644,7 +644,11 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, pm_runtime_get_sync(&dev->adev->dev); - clk_enable(dev->clk); + status = clk_prepare_enable(dev->clk); + if (status) { + dev_err(&dev->adev->dev, "can't prepare_enable clock\n"); + goto out_clk; + } status = init_hw(dev); if (status) @@ -671,7 +675,8 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap, } out: - clk_disable(dev->clk); + clk_disable_unprepare(dev->clk); +out_clk: pm_runtime_put_sync(&dev->adev->dev); dev->busy = false; -- cgit v1.1 From 91b370a0dbda5de92c2cf4c3bc0d18d6bf08f05f Mon Sep 17 00:00:00 2001 From: Laxman Dewangan Date: Thu, 1 Nov 2012 22:08:14 +0530 Subject: i2c: tegra: set irq name as device name When watching the irqs name of tegra i2c, all instances irq name shows as tegra_i2c. Passing the device name properly to have the irq names with instance like tegra-i2c.0, tegra-i2c.1 etc. Signed-off-by: Laxman Dewangan Acked-by: Jean Delvare Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-tegra.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index f981ac4..dcea77b 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -742,7 +742,7 @@ static int __devinit tegra_i2c_probe(struct platform_device *pdev) } ret = devm_request_irq(&pdev->dev, i2c_dev->irq, - tegra_i2c_isr, 0, pdev->name, i2c_dev); + tegra_i2c_isr, 0, dev_name(&pdev->dev), i2c_dev); if (ret) { dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq); return ret; -- cgit v1.1