diff options
Diffstat (limited to 'drivers/staging/nvec')
| -rw-r--r-- | drivers/staging/nvec/nvec.c | 41 |
1 files changed, 24 insertions, 17 deletions
diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c index e5ca78e57384..d67d2f3338b2 100644 --- a/drivers/staging/nvec/nvec.c +++ b/drivers/staging/nvec/nvec.c @@ -571,6 +571,22 @@ static void nvec_tx_set(struct nvec_chip *nvec) } /** + * tegra_i2c_writel - safely write to an I2C client controller register + * @val: value to be written + * @reg: register to write to + * + * A write to an I2C controller register needs to be read back to make sure + * that the value has arrived. + */ +static void tegra_i2c_writel(u32 val, void *reg) +{ + writel_relaxed(val, reg); + + /* read back register to make sure that register writes completed */ + readl_relaxed(reg); +} + +/** * nvec_interrupt - Interrupt handler * @irq: The IRQ * @dev: The nvec device @@ -604,7 +620,7 @@ static irqreturn_t nvec_interrupt(int irq, void *dev) if ((status & RNW) == 0) { received = readl(nvec->base + I2C_SL_RCVD); if (status & RCVD) - writel(0, nvec->base + I2C_SL_RCVD); + tegra_i2c_writel(0, nvec->base + I2C_SL_RCVD); } if (status == (I2C_SL_IRQ | RCVD)) @@ -696,7 +712,7 @@ static irqreturn_t nvec_interrupt(int irq, void *dev) /* Send data if requested, but not on end of transmission */ if ((status & (RNW | END_TRANS)) == RNW) - writel(to_send, nvec->base + I2C_SL_RCVD); + tegra_i2c_writel(to_send, nvec->base + I2C_SL_RCVD); /* If we have send the first byte */ if (status == (I2C_SL_IRQ | RNW | RCVD)) @@ -713,15 +729,6 @@ static irqreturn_t nvec_interrupt(int irq, void *dev) status & RCVD ? " RCVD" : "", status & RNW ? " RNW" : ""); - /* - * TODO: replace the udelay with a read back after each writel above - * in order to work around a hardware issue, see i2c-tegra.c - * - * Unfortunately, this change causes an initialisation issue with the - * touchpad, which needs to be fixed first. - */ - udelay(100); - return IRQ_HANDLED; } @@ -737,15 +744,15 @@ static void tegra_init_i2c_slave(struct nvec_chip *nvec) val = I2C_CNFG_NEW_MASTER_SFM | I2C_CNFG_PACKET_MODE_EN | (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT); - writel(val, nvec->base + I2C_CNFG); + tegra_i2c_writel(val, nvec->base + I2C_CNFG); clk_set_rate(nvec->i2c_clk, 8 * 80000); - writel(I2C_SL_NEWSL, nvec->base + I2C_SL_CNFG); - writel(0x1E, nvec->base + I2C_SL_DELAY_COUNT); + tegra_i2c_writel(I2C_SL_NEWSL, nvec->base + I2C_SL_CNFG); + tegra_i2c_writel(0x1E, nvec->base + I2C_SL_DELAY_COUNT); - writel(nvec->i2c_addr >> 1, nvec->base + I2C_SL_ADDR1); - writel(0, nvec->base + I2C_SL_ADDR2); + tegra_i2c_writel(nvec->i2c_addr >> 1, nvec->base + I2C_SL_ADDR1); + tegra_i2c_writel(0, nvec->base + I2C_SL_ADDR2); enable_irq(nvec->irq); } @@ -754,7 +761,7 @@ static void tegra_init_i2c_slave(struct nvec_chip *nvec) static void nvec_disable_i2c_slave(struct nvec_chip *nvec) { disable_irq(nvec->irq); - writel(I2C_SL_NEWSL | I2C_SL_NACK, nvec->base + I2C_SL_CNFG); + tegra_i2c_writel(I2C_SL_NEWSL | I2C_SL_NACK, nvec->base + I2C_SL_CNFG); clk_disable_unprepare(nvec->i2c_clk); } #endif |