From 63cab195bf498676619951e81ad5791e9d47c420 Mon Sep 17 00:00:00 2001 From: Anurag Kumar Vulisha Date: Fri, 10 Jul 2015 20:10:14 +0530 Subject: [PATCH] i2c: removed work arounds in i2c driver for Zynq Ultrascale+ MPSoC Cadence 1.0 version has bugs which have been fixed in the cadence 1.4 version. This patch removes the quirks present in the driver for cadence 1.4 version. Signed-off-by: Anurag Kumar Vulisha [wsa: fixed indentation issues in r1p10_i2c_def] Signed-off-by: Wolfram Sang --- .../devicetree/bindings/i2c/i2c-cadence.txt | 6 +- drivers/i2c/busses/i2c-cadence.c | 68 ++++++++++++++++--- 2 files changed, 62 insertions(+), 12 deletions(-) diff --git a/Documentation/devicetree/bindings/i2c/i2c-cadence.txt b/Documentation/devicetree/bindings/i2c/i2c-cadence.txt index 7cb0b5608f49..ebaa90c58c8e 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-cadence.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-cadence.txt @@ -2,7 +2,11 @@ Binding for the Cadence I2C controller Required properties: - reg: Physical base address and size of the controller's register area. - - compatible: Compatibility string. Must be 'cdns,i2c-r1p10'. + - compatible: Should contain one of: + * "cdns,i2c-r1p10" + Note: Use this when cadence i2c controller version 1.0 is used. + * "cdns,i2c-r1p14" + Note: Use this when cadence i2c controller version 1.4 is used. - clocks: Input clock specifier. Refer to common clock bindings. - interrupts: Interrupt specifier. Refer to interrupt bindings. - #address-cells: Should be 1. diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c index 2ee78e099d30..18e48ae4a60d 100644 --- a/drivers/i2c/busses/i2c-cadence.c +++ b/drivers/i2c/busses/i2c-cadence.c @@ -17,6 +17,7 @@ #include #include #include +#include /* Register offsets for the I2C device. */ #define CDNS_I2C_CR_OFFSET 0x00 /* Control Register, RW */ @@ -113,6 +114,8 @@ #define CDNS_I2C_TIMEOUT_MAX 0xFF +#define CDNS_I2C_BROKEN_HOLD_BIT BIT(0) + #define cdns_i2c_readreg(offset) readl_relaxed(id->membase + offset) #define cdns_i2c_writereg(val, offset) writel_relaxed(val, id->membase + offset) @@ -135,6 +138,7 @@ * @bus_hold_flag: Flag used in repeated start for clearing HOLD bit * @clk: Pointer to struct clk * @clk_rate_change_nb: Notifier block for clock rate changes + * @quirks: flag for broken hold bit usage in r1p10 */ struct cdns_i2c { void __iomem *membase; @@ -154,6 +158,11 @@ struct cdns_i2c { unsigned int bus_hold_flag; struct clk *clk; struct notifier_block clk_rate_change_nb; + u32 quirks; +}; + +struct cdns_platform_data { + u32 quirks; }; #define to_cdns_i2c(_nb) container_of(_nb, struct cdns_i2c, \ @@ -172,6 +181,12 @@ static void cdns_i2c_clear_bus_hold(struct cdns_i2c *id) cdns_i2c_writereg(reg & ~CDNS_I2C_CR_HOLD, CDNS_I2C_CR_OFFSET); } +static inline bool cdns_is_holdquirk(struct cdns_i2c *id, bool hold_wrkaround) +{ + return (hold_wrkaround && + (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1)); +} + /** * cdns_i2c_isr - Interrupt handler for the I2C device * @irq: irq number for the I2C device @@ -186,6 +201,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) { unsigned int isr_status, avail_bytes, updatetx; unsigned int bytes_to_send; + bool hold_quirk; struct cdns_i2c *id = ptr; /* Signal completion only after everything is updated */ int done_flag = 0; @@ -208,6 +224,8 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) if (id->recv_count > id->curr_recv_count) updatetx = 1; + hold_quirk = (id->quirks & CDNS_I2C_BROKEN_HOLD_BIT) && updatetx; + /* When receiving, handle data interrupt and completion interrupt */ if (id->p_recv_buf && ((isr_status & CDNS_I2C_IXR_COMP) || @@ -229,8 +247,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) id->recv_count--; id->curr_recv_count--; - if (updatetx && - (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1)) + if (cdns_is_holdquirk(id, hold_quirk)) break; } @@ -241,8 +258,7 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) * maintain transfer size non-zero while performing a large * receive operation. */ - if (updatetx && - (id->curr_recv_count == CDNS_I2C_FIFO_DEPTH + 1)) { + if (cdns_is_holdquirk(id, hold_quirk)) { /* wait while fifo is full */ while (cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET) != (id->curr_recv_count - CDNS_I2C_FIFO_DEPTH)) @@ -264,6 +280,22 @@ static irqreturn_t cdns_i2c_isr(int irq, void *ptr) CDNS_I2C_XFER_SIZE_OFFSET); id->curr_recv_count = id->recv_count; } + } else if (id->recv_count && !hold_quirk && + !id->curr_recv_count) { + + /* Set the slave address in address register*/ + cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK, + CDNS_I2C_ADDR_OFFSET); + + if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) { + cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE, + CDNS_I2C_XFER_SIZE_OFFSET); + id->curr_recv_count = CDNS_I2C_TRANSFER_SIZE; + } else { + cdns_i2c_writereg(id->recv_count, + CDNS_I2C_XFER_SIZE_OFFSET); + id->curr_recv_count = id->recv_count; + } } /* Clear hold (if not repeated start) and signal completion */ @@ -535,11 +567,13 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int ret, count; u32 reg; struct cdns_i2c *id = adap->algo_data; + bool hold_quirk; /* Check if the bus is free */ if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) return -EAGAIN; + hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT); /* * Set the flag to one when multiple messages are to be * processed with a repeated start. @@ -552,7 +586,7 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, * followed by any other message, an error is returned * indicating that this sequence is not supported. */ - for (count = 0; count < num - 1; count++) { + for (count = 0; (count < num - 1 && hold_quirk); count++) { if (msgs[count].flags & I2C_M_RD) { dev_warn(adap->dev.parent, "Can't do repeated start after a receive message\n"); @@ -815,6 +849,17 @@ static int __maybe_unused cdns_i2c_resume(struct device *_dev) static SIMPLE_DEV_PM_OPS(cdns_i2c_dev_pm_ops, cdns_i2c_suspend, cdns_i2c_resume); +static const struct cdns_platform_data r1p10_i2c_def = { + .quirks = CDNS_I2C_BROKEN_HOLD_BIT, +}; + +static const struct of_device_id cdns_i2c_of_match[] = { + { .compatible = "cdns,i2c-r1p10", .data = &r1p10_i2c_def }, + { .compatible = "cdns,i2c-r1p14",}, + { /* end of table */ } +}; +MODULE_DEVICE_TABLE(of, cdns_i2c_of_match); + /** * cdns_i2c_probe - Platform registration call * @pdev: Handle to the platform device structure @@ -830,6 +875,7 @@ static int cdns_i2c_probe(struct platform_device *pdev) struct resource *r_mem; struct cdns_i2c *id; int ret; + const struct of_device_id *match; id = devm_kzalloc(&pdev->dev, sizeof(*id), GFP_KERNEL); if (!id) @@ -837,6 +883,12 @@ static int cdns_i2c_probe(struct platform_device *pdev) platform_set_drvdata(pdev, id); + match = of_match_node(cdns_i2c_of_match, pdev->dev.of_node); + if (match && match->data) { + const struct cdns_platform_data *data = match->data; + id->quirks = data->quirks; + } + r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); id->membase = devm_ioremap_resource(&pdev->dev, r_mem); if (IS_ERR(id->membase)) @@ -935,12 +987,6 @@ static int cdns_i2c_remove(struct platform_device *pdev) return 0; } -static const struct of_device_id cdns_i2c_of_match[] = { - { .compatible = "cdns,i2c-r1p10", }, - { /* end of table */ } -}; -MODULE_DEVICE_TABLE(of, cdns_i2c_of_match); - static struct platform_driver cdns_i2c_drv = { .driver = { .name = DRIVER_NAME, -- 2.20.1