From 5d69d5a00f80488ddcb4dee7d1374a0709398178 Mon Sep 17 00:00:00 2001 From: Kimriver Liu Date: Fri, 13 Sep 2024 11:31:46 +0800 Subject: [PATCH 1/4] i2c: designware: fix controller is holding SCL low while ENABLE bit is disabled It was observed that issuing the ABORT bit (IC_ENABLE[1]) will not work when IC_ENABLE is already disabled. Check if the ENABLE bit (IC_ENABLE[0]) is disabled when the controller is holding SCL low. If the ENABLE bit is disabled, the software needs to enable it before trying to issue the ABORT bit. otherwise, the controller ignores any write to ABORT bit. These kernel logs show up whenever an I2C transaction is attempted after this failure. i2c_designware e95e0000.i2c: timeout waiting for bus ready i2c_designware e95e0000.i2c: timeout in disabling adapter The patch fixes the issue where the controller cannot be disabled while SCL is held low if the ENABLE bit is already disabled. Fixes: 2409205acd3c ("i2c: designware: fix __i2c_dw_disable() in case master is holding SCL low") Signed-off-by: Kimriver Liu Cc: # v6.6+ Reviewed-by: Mika Westerberg Acked-by: Jarkko Nikula Reviewed-by: Andy Shevchenko Signed-off-by: Andi Shyti --- drivers/i2c/busses/i2c-designware-common.c | 14 ++++++++ drivers/i2c/busses/i2c-designware-core.h | 1 + drivers/i2c/busses/i2c-designware-master.c | 38 ++++++++++++++++++++++ 3 files changed, 53 insertions(+) diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c index 080204182bb5..f31d352d98b5 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -523,6 +523,7 @@ int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev) void __i2c_dw_disable(struct dw_i2c_dev *dev) { + struct i2c_timings *t = &dev->timings; unsigned int raw_intr_stats; unsigned int enable; int timeout = 100; @@ -535,6 +536,19 @@ void __i2c_dw_disable(struct dw_i2c_dev *dev) abort_needed = raw_intr_stats & DW_IC_INTR_MST_ON_HOLD; if (abort_needed) { + if (!(enable & DW_IC_ENABLE_ENABLE)) { + regmap_write(dev->map, DW_IC_ENABLE, DW_IC_ENABLE_ENABLE); + /* + * Wait 10 times the signaling period of the highest I2C + * transfer supported by the driver (for 400KHz this is + * 25us) to ensure the I2C ENABLE bit is already set + * as described in the DesignWare I2C databook. + */ + fsleep(DIV_ROUND_CLOSEST_ULL(10 * MICRO, t->bus_freq_hz)); + /* Set ENABLE bit before setting ABORT */ + enable |= DW_IC_ENABLE_ENABLE; + } + regmap_write(dev->map, DW_IC_ENABLE, enable | DW_IC_ENABLE_ABORT); ret = regmap_read_poll_timeout(dev->map, DW_IC_ENABLE, enable, !(enable & DW_IC_ENABLE_ABORT), 10, diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 1ac2afd03a0a..8e8854ec9882 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -108,6 +108,7 @@ DW_IC_INTR_RX_UNDER | \ DW_IC_INTR_RD_REQ) +#define DW_IC_ENABLE_ENABLE BIT(0) #define DW_IC_ENABLE_ABORT BIT(1) #define DW_IC_STATUS_ACTIVITY BIT(0) diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index e46f1b22c360..e8ac9a7bf0b3 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -271,6 +271,34 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) __i2c_dw_write_intr_mask(dev, DW_IC_INTR_MASTER_MASK); } +/* + * This function waits for the controller to be idle before disabling I2C + * When the controller is not in the IDLE state, the MST_ACTIVITY bit + * (IC_STATUS[5]) is set. + * + * Values: + * 0x1 (ACTIVE): Controller not idle + * 0x0 (IDLE): Controller is idle + * + * The function is called after completing the current transfer. + * + * Returns: + * False when the controller is in the IDLE state. + * True when the controller is in the ACTIVE state. + */ +static bool i2c_dw_is_controller_active(struct dw_i2c_dev *dev) +{ + u32 status; + + regmap_read(dev->map, DW_IC_STATUS, &status); + if (!(status & DW_IC_STATUS_MASTER_ACTIVITY)) + return false; + + return regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status, + !(status & DW_IC_STATUS_MASTER_ACTIVITY), + 1100, 20000) != 0; +} + static int i2c_dw_check_stopbit(struct dw_i2c_dev *dev) { u32 val; @@ -806,6 +834,16 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) goto done; } + /* + * This happens rarely (~1:500) and is hard to reproduce. Debug trace + * showed that IC_STATUS had value of 0x23 when STOP_DET occurred, + * if disable IC_ENABLE.ENABLE immediately that can result in + * IC_RAW_INTR_STAT.MASTER_ON_HOLD holding SCL low. Check if + * controller is still ACTIVE before disabling I2C. + */ + if (i2c_dw_is_controller_active(dev)) + dev_err(dev->dev, "controller active\n"); + /* * We must disable the adapter before returning and signaling the end * of the current transfer. Otherwise the hardware might continue From f2990f8630531a99cad4dc5c44cb2a11ded42492 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 12 Sep 2024 12:46:31 +0200 Subject: [PATCH 2/4] i2c: synquacer: Deal with optional PCLK correctly ACPI boot does not provide clocks and regulators, but instead, provides the PCLK rate directly, and enables the clock in firmware. So deal gracefully with this. Fixes: 55750148e559 ("i2c: synquacer: Fix an error handling path in synquacer_i2c_probe()") Cc: stable@vger.kernel.org # v6.10+ Cc: Andi Shyti Cc: Christophe JAILLET Signed-off-by: Ard Biesheuvel Signed-off-by: Andi Shyti --- drivers/i2c/busses/i2c-synquacer.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-synquacer.c b/drivers/i2c/busses/i2c-synquacer.c index 4eccbcd0fbfc..bbb9062669e4 100644 --- a/drivers/i2c/busses/i2c-synquacer.c +++ b/drivers/i2c/busses/i2c-synquacer.c @@ -550,12 +550,13 @@ static int synquacer_i2c_probe(struct platform_device *pdev) device_property_read_u32(&pdev->dev, "socionext,pclk-rate", &i2c->pclkrate); - pclk = devm_clk_get_enabled(&pdev->dev, "pclk"); + pclk = devm_clk_get_optional_enabled(&pdev->dev, "pclk"); if (IS_ERR(pclk)) return dev_err_probe(&pdev->dev, PTR_ERR(pclk), "failed to get and enable clock\n"); - i2c->pclkrate = clk_get_rate(pclk); + if (pclk) + i2c->pclkrate = clk_get_rate(pclk); if (i2c->pclkrate < SYNQUACER_I2C_MIN_CLK_RATE || i2c->pclkrate > SYNQUACER_I2C_MAX_CLK_RATE) From 6d3405415f887aef5774c04ae9fefae63d82bdaf Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Tue, 24 Sep 2024 11:34:18 +0200 Subject: [PATCH 3/4] i2c: keba: I2C_KEBA should depend on KEBA_CP500 The KEBA I2C controller is only present on KEBA PLC devices. Hence add a dependency on KEBA_CP500, to prevent asking the user about this driver when configuring a kernel without KEBA CP500 system FPGA support. Fixes: c7e08c816cd2fdf8 ("i2c: keba: Add KEBA I2C controller support") Signed-off-by: Geert Uytterhoeven Reviewed-by: Gerhard Engleder Signed-off-by: Andi Shyti --- drivers/i2c/busses/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 53f18b351f53..6b3ba7e5723a 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -782,6 +782,7 @@ config I2C_JZ4780 config I2C_KEBA tristate "KEBA I2C controller support" depends on HAS_IOMEM + depends on KEBA_CP500 || COMPILE_TEST select AUXILIARY_BUS help This driver supports the I2C controller found in KEBA system FPGA From 0c8d604dea437b69a861479b413d629bc9b3da70 Mon Sep 17 00:00:00 2001 From: Jinjie Ruan Date: Mon, 23 Sep 2024 11:42:50 +0800 Subject: [PATCH 4/4] i2c: xiic: Fix pm_runtime_set_suspended() with runtime pm enabled It is not valid to call pm_runtime_set_suspended() for devices with runtime PM enabled because it returns -EAGAIN if it is enabled already and working. So, call pm_runtime_disable() before to fix it. Fixes: 36ecbcab84d0 ("i2c: xiic: Implement power management") Cc: # v4.6+ Signed-off-by: Jinjie Ruan Signed-off-by: Andi Shyti --- drivers/i2c/busses/i2c-xiic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c index 4c89aad02451..1d68177241a6 100644 --- a/drivers/i2c/busses/i2c-xiic.c +++ b/drivers/i2c/busses/i2c-xiic.c @@ -1337,8 +1337,8 @@ static int xiic_i2c_probe(struct platform_device *pdev) return 0; err_pm_disable: - pm_runtime_set_suspended(&pdev->dev); pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); return ret; }