diff --git a/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml b/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml index 51534953a69cf..9401dc2d50522 100644 --- a/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml +++ b/Documentation/devicetree/bindings/i2c/qcom,i2c-geni-qcom.yaml @@ -60,6 +60,13 @@ properties: power-domains: maxItems: 1 + qcom,qup-multi-owner: + type: boolean + description: + Indicates that the QUP-based controller is shared with one or more + other system processors and must not be assumed to have exclusive + ownership by the operating system. + reg: maxItems: 1 diff --git a/drivers/dma/qcom/gpi.c b/drivers/dma/qcom/gpi.c index c9a6f610ffd9f..3cb20d854b00e 100644 --- a/drivers/dma/qcom/gpi.c +++ b/drivers/dma/qcom/gpi.c @@ -2,6 +2,7 @@ /* * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved. * Copyright (c) 2020, Linaro Limited + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. */ #include @@ -67,6 +68,14 @@ #define TRE_DMA_LEN GENMASK(23, 0) #define TRE_DMA_IMMEDIATE_LEN GENMASK(3, 0) +/* Lock TRE */ +#define TRE_LOCK BIT(0) +#define TRE_MINOR_TYPE GENMASK(19, 16) +#define TRE_MAJOR_TYPE GENMASK(23, 20) + +/* Unlock TRE */ +#define TRE_UNLOCK BIT(8) + /* Register offsets from gpi-top */ #define GPII_n_CH_k_CNTXT_0_OFFS(n, k) (0x20000 + (0x4000 * (n)) + (0x80 * (k))) #define GPII_n_CH_k_CNTXT_0_EL_SIZE GENMASK(31, 24) @@ -518,7 +527,7 @@ struct gpii { bool ieob_set; }; -#define MAX_TRE 3 +#define MAX_TRE 5 struct gpi_desc { struct virt_dma_desc vd; @@ -1625,12 +1634,27 @@ static int gpi_create_i2c_tre(struct gchan *chan, struct gpi_desc *desc, unsigned long flags) { struct gpi_i2c_config *i2c = chan->config; + enum gpi_lock_action lock_action = i2c->lock_action; struct device *dev = chan->gpii->gpi_dev->dev; unsigned int tre_idx = 0; dma_addr_t address; struct gpi_tre *tre; unsigned int i; + /* Optional lock TRE before transfer */ + if (lock_action == GPI_LOCK_ACQUIRE) { + tre = &desc->tre[tre_idx]; + tre_idx++; + + tre->dword[0] = 0; + tre->dword[1] = 0; + tre->dword[2] = 0; + tre->dword[3] = u32_encode_bits(1, TRE_LOCK); + tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_IEOB); + tre->dword[3] |= u32_encode_bits(0, TRE_MINOR_TYPE); + tre->dword[3] |= u32_encode_bits(3, TRE_MAJOR_TYPE); + } + /* first create config tre if applicable */ if (i2c->set_config) { tre = &desc->tre[tre_idx]; @@ -1690,6 +1714,24 @@ static int gpi_create_i2c_tre(struct gchan *chan, struct gpi_desc *desc, if (!(flags & DMA_PREP_INTERRUPT)) tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_BEI); + + /* If multi-owner and this is the release boundary, chain it */ + if (i2c->lock_action == GPI_LOCK_RELEASE) + tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_CHAIN); + } + + /* Optional unlock TRE after transfer */ + if (lock_action == GPI_LOCK_RELEASE && i2c->op != I2C_READ) { + tre = &desc->tre[tre_idx]; + tre_idx++; + + tre->dword[0] = 0; + tre->dword[1] = 0; + tre->dword[2] = 0; + tre->dword[3] = u32_encode_bits(1, TRE_UNLOCK); + tre->dword[3] |= u32_encode_bits(1, TRE_FLAGS_IEOB); + tre->dword[3] |= u32_encode_bits(1, TRE_MINOR_TYPE); + tre->dword[3] |= u32_encode_bits(3, TRE_MAJOR_TYPE); } for (i = 0; i < tre_idx; i++) diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index a4acb78fafb66..243dac7e483ed 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -815,6 +815,14 @@ static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], i if (i < num - 1) peripheral.stretch = 1; + peripheral.lock_action = GPI_LOCK_NONE; + if (gi2c->se.multi_owner) { + if (i == 0) + peripheral.lock_action = GPI_LOCK_ACQUIRE; + else if (i == num - 1) + peripheral.lock_action = GPI_LOCK_RELEASE; + } + peripheral.addr = msgs[i].addr; if (i > 0 && (!(msgs[i].flags & I2C_M_RD))) peripheral.multi_msg = false; @@ -1014,6 +1022,17 @@ static int geni_i2c_probe(struct platform_device *pdev) gi2c->clk_freq_out = I2C_MAX_STANDARD_MODE_FREQ; } + if (of_property_read_bool(pdev->dev.of_node, "qcom,qup-multi-owner")) { + /* + * Multi-owner controller configuration: the controller may be + * used by another system processor. Mark the SE as shared so + * common GENI resource handling can avoid pin state changes + * that would disrupt the other user. + */ + gi2c->se.multi_owner = true; + dev_dbg(&pdev->dev, "I2C controller is shared with another system processor\n"); + } + if (has_acpi_companion(dev)) ACPI_COMPANION_SET(&gi2c->adap.dev, ACPI_COMPANION(dev)); @@ -1089,7 +1108,9 @@ static int geni_i2c_probe(struct platform_device *pdev) } if (fifo_disable) { - /* FIFO is disabled, so we can only use GPI DMA */ + /* FIFO is disabled, so we can only use GPI DMA. + * SE can be shared in GSI mode between subsystems, each SS owns a GPII. + */ gi2c->gpi_mode = true; ret = setup_gpi_dma(gi2c); if (ret) @@ -1098,6 +1119,10 @@ static int geni_i2c_probe(struct platform_device *pdev) dev_dbg(dev, "Using GPI DMA mode for I2C\n"); } else { gi2c->gpi_mode = false; + + if (gi2c->se.multi_owner) + dev_err_probe(dev, -EINVAL, "I2C sharing not supported in non GSI mode\n"); + tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se); /* I2C Master Hub Serial Elements doesn't have the HW_PARAM_0 register */ diff --git a/drivers/soc/qcom/qcom-geni-se.c b/drivers/soc/qcom/qcom-geni-se.c index cd1779b6a91a7..1a60832ace168 100644 --- a/drivers/soc/qcom/qcom-geni-se.c +++ b/drivers/soc/qcom/qcom-geni-se.c @@ -597,10 +597,17 @@ int geni_se_resources_off(struct geni_se *se) if (has_acpi_companion(se->dev)) return 0; - - ret = pinctrl_pm_select_sleep_state(se->dev); - if (ret) - return ret; + /* + * Select the "sleep" pinctrl state only when the serial engine is + * exclusively owned by this system processor. For shared controller + * configurations, another system processor may still be using the pins, + * and switching them to "sleep" can disrupt ongoing transfers. + */ + if (!se->multi_owner) { + ret = pinctrl_pm_select_sleep_state(se->dev); + if (ret) + return ret; + } geni_se_clks_off(se); return 0; diff --git a/include/linux/dma/qcom-gpi-dma.h b/include/linux/dma/qcom-gpi-dma.h index 6680dd1a43c68..36cbb85499b4c 100644 --- a/include/linux/dma/qcom-gpi-dma.h +++ b/include/linux/dma/qcom-gpi-dma.h @@ -1,6 +1,7 @@ /* SPDX-License-Identifier: GPL-2.0 */ /* * Copyright (c) 2020, Linaro Limited + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. */ #ifndef QCOM_GPI_DMA_H @@ -51,6 +52,21 @@ enum i2c_op { I2C_READ, }; +/** + * enum gpi_lock_action - request lock/unlock TRE sequencing + * @GPI_LOCK_NONE: No lock/unlock TRE requested for this transfer + * @GPI_LOCK_ACQUIRE: Emit a lock TRE before the transfer + * @GPI_LOCK_RELEASE: Emit an unlock TRE after the transfer + * + * Used by protocol drivers for multi-owner controller setups (e.g. when + * DeviceTree indicates the controller is shared via qcom,qup-multi-owner). + */ +enum gpi_lock_action { + GPI_LOCK_NONE = 0, + GPI_LOCK_ACQUIRE, + GPI_LOCK_RELEASE, +}; + /** * struct gpi_i2c_config - i2c config for peripheral * @@ -65,6 +81,7 @@ enum i2c_op { * @rx_len: receive length for buffer * @op: i2c cmd * @muli-msg: is part of multi i2c r-w msgs + * @lock_action: request lock/unlock TRE sequencing for this transfer */ struct gpi_i2c_config { u8 set_config; @@ -78,6 +95,7 @@ struct gpi_i2c_config { u32 rx_len; enum i2c_op op; bool multi_msg; + enum gpi_lock_action lock_action; }; #endif /* QCOM_GPI_DMA_H */ diff --git a/include/linux/soc/qcom/geni-se.h b/include/linux/soc/qcom/geni-se.h index 0a984e2579fe2..326744e311cea 100644 --- a/include/linux/soc/qcom/geni-se.h +++ b/include/linux/soc/qcom/geni-se.h @@ -63,6 +63,7 @@ struct geni_icc_path { * @num_clk_levels: Number of valid clock levels in clk_perf_tbl * @clk_perf_tbl: Table of clock frequency input to serial engine clock * @icc_paths: Array of ICC paths for SE + * @multi_owner: True if SE is shared between multiprocessors. */ struct geni_se { void __iomem *base; @@ -72,6 +73,7 @@ struct geni_se { unsigned int num_clk_levels; unsigned long *clk_perf_tbl; struct geni_icc_path icc_paths[3]; + bool multi_owner; }; /* Common SE registers */