diff options
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/busses/i2c-qcom-geni.c | 308 |
1 files changed, 280 insertions, 28 deletions
diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c index 6d635a7c104c..fc1dcc19f2a1 100644 --- a/drivers/i2c/busses/i2c-qcom-geni.c +++ b/drivers/i2c/busses/i2c-qcom-geni.c @@ -3,7 +3,9 @@ #include <linux/acpi.h> #include <linux/clk.h> +#include <linux/dmaengine.h> #include <linux/dma-mapping.h> +#include <linux/dma/qcom-gpi-dma.h> #include <linux/err.h> #include <linux/i2c.h> #include <linux/interrupt.h> @@ -48,6 +50,9 @@ #define LOW_COUNTER_SHFT 10 #define CYCLE_COUNTER_MSK GENMASK(9, 0) +#define I2C_PACK_TX BIT(0) +#define I2C_PACK_RX BIT(1) + enum geni_i2c_err_code { GP_IRQ0, NACK, @@ -89,6 +94,9 @@ struct geni_i2c_dev { void *dma_buf; size_t xfer_len; dma_addr_t dma_addr; + struct dma_chan *tx_c; + struct dma_chan *rx_c; + bool gpi_mode; }; struct geni_i2c_err_log { @@ -456,12 +464,207 @@ static int geni_i2c_tx_one_msg(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, return gi2c->err; } +static void i2c_gpi_cb_result(void *cb, const struct dmaengine_result *result) +{ + struct geni_i2c_dev *gi2c = cb; + + if (result->result != DMA_TRANS_NOERROR) { + dev_err(gi2c->se.dev, "DMA txn failed:%d\n", result->result); + gi2c->err = -EIO; + } else if (result->residue) { + dev_dbg(gi2c->se.dev, "DMA xfer has pending: %d\n", result->residue); + } + + complete(&gi2c->done); +} + +static void geni_i2c_gpi_unmap(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, + void *tx_buf, dma_addr_t tx_addr, + void *rx_buf, dma_addr_t rx_addr) +{ + if (tx_buf) { + dma_unmap_single(gi2c->se.dev->parent, tx_addr, msg->len, DMA_TO_DEVICE); + i2c_put_dma_safe_msg_buf(tx_buf, msg, false); + } + + if (rx_buf) { + dma_unmap_single(gi2c->se.dev->parent, rx_addr, msg->len, DMA_FROM_DEVICE); + i2c_put_dma_safe_msg_buf(rx_buf, msg, false); + } +} + +static int geni_i2c_gpi(struct geni_i2c_dev *gi2c, struct i2c_msg *msg, + struct dma_slave_config *config, dma_addr_t *dma_addr_p, + void **buf, unsigned int op, struct dma_chan *dma_chan) +{ + struct gpi_i2c_config *peripheral; + unsigned int flags; + void *dma_buf; + dma_addr_t addr; + enum dma_data_direction map_dirn; + enum dma_transfer_direction dma_dirn; + struct dma_async_tx_descriptor *desc; + int ret; + + peripheral = config->peripheral_config; + + dma_buf = i2c_get_dma_safe_msg_buf(msg, 1); + if (!dma_buf) + return -ENOMEM; + + if (op == I2C_WRITE) + map_dirn = DMA_TO_DEVICE; + else + map_dirn = DMA_FROM_DEVICE; + + addr = dma_map_single(gi2c->se.dev->parent, dma_buf, msg->len, map_dirn); + if (dma_mapping_error(gi2c->se.dev->parent, addr)) { + i2c_put_dma_safe_msg_buf(dma_buf, msg, false); + return -ENOMEM; + } + + /* set the length as message for rx txn */ + peripheral->rx_len = msg->len; + peripheral->op = op; + + ret = dmaengine_slave_config(dma_chan, config); + if (ret) { + dev_err(gi2c->se.dev, "dma config error: %d for op:%d\n", ret, op); + goto err_config; + } + + peripheral->set_config = 0; + peripheral->multi_msg = true; + flags = DMA_PREP_INTERRUPT | DMA_CTRL_ACK; + + if (op == I2C_WRITE) + dma_dirn = DMA_MEM_TO_DEV; + else + dma_dirn = DMA_DEV_TO_MEM; + + desc = dmaengine_prep_slave_single(dma_chan, addr, msg->len, dma_dirn, flags); + if (!desc) { + dev_err(gi2c->se.dev, "prep_slave_sg failed\n"); + ret = -EIO; + goto err_config; + } + + desc->callback_result = i2c_gpi_cb_result; + desc->callback_param = gi2c; + + dmaengine_submit(desc); + *dma_addr_p = addr; + + return 0; + +err_config: + dma_unmap_single(gi2c->se.dev->parent, addr, msg->len, map_dirn); + i2c_put_dma_safe_msg_buf(dma_buf, msg, false); + return ret; +} + +static int geni_i2c_gpi_xfer(struct geni_i2c_dev *gi2c, struct i2c_msg msgs[], int num) +{ + struct dma_slave_config config = {}; + struct gpi_i2c_config peripheral = {}; + int i, ret = 0, timeout; + dma_addr_t tx_addr, rx_addr; + void *tx_buf = NULL, *rx_buf = NULL; + const struct geni_i2c_clk_fld *itr = gi2c->clk_fld; + + config.peripheral_config = &peripheral; + config.peripheral_size = sizeof(peripheral); + + peripheral.pack_enable = I2C_PACK_TX | I2C_PACK_RX; + peripheral.cycle_count = itr->t_cycle_cnt; + peripheral.high_count = itr->t_high_cnt; + peripheral.low_count = itr->t_low_cnt; + peripheral.clk_div = itr->clk_div; + peripheral.set_config = 1; + peripheral.multi_msg = false; + + for (i = 0; i < num; i++) { + gi2c->cur = &msgs[i]; + gi2c->err = 0; + dev_dbg(gi2c->se.dev, "msg[%d].len:%d\n", i, gi2c->cur->len); + + peripheral.stretch = 0; + if (i < num - 1) + peripheral.stretch = 1; + + peripheral.addr = msgs[i].addr; + + if (msgs[i].flags & I2C_M_RD) { + ret = geni_i2c_gpi(gi2c, &msgs[i], &config, + &rx_addr, &rx_buf, I2C_READ, gi2c->rx_c); + if (ret) + goto err; + } + + ret = geni_i2c_gpi(gi2c, &msgs[i], &config, + &tx_addr, &tx_buf, I2C_WRITE, gi2c->tx_c); + if (ret) + goto err; + + if (msgs[i].flags & I2C_M_RD) + dma_async_issue_pending(gi2c->rx_c); + dma_async_issue_pending(gi2c->tx_c); + + timeout = wait_for_completion_timeout(&gi2c->done, XFER_TIMEOUT); + if (!timeout) { + dev_err(gi2c->se.dev, "I2C timeout gpi flags:%d addr:0x%x\n", + gi2c->cur->flags, gi2c->cur->addr); + gi2c->err = -ETIMEDOUT; + goto err; + } + + if (gi2c->err) { + ret = gi2c->err; + goto err; + } + + geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr); + } + + return num; + +err: + dev_err(gi2c->se.dev, "GPI transfer failed: %d\n", ret); + dmaengine_terminate_sync(gi2c->rx_c); + dmaengine_terminate_sync(gi2c->tx_c); + geni_i2c_gpi_unmap(gi2c, &msgs[i], tx_buf, tx_addr, rx_buf, rx_addr); + return ret; +} + +static int geni_i2c_fifo_xfer(struct geni_i2c_dev *gi2c, + struct i2c_msg msgs[], int num) +{ + int i, ret = 0; + + for (i = 0; i < num; i++) { + u32 m_param = i < (num - 1) ? STOP_STRETCH : 0; + + m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK); + + gi2c->cur = &msgs[i]; + if (msgs[i].flags & I2C_M_RD) + ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param); + else + ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param); + + if (ret) + return ret; + } + + return num; +} + static int geni_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct geni_i2c_dev *gi2c = i2c_get_adapdata(adap); - int i, ret; + int ret; gi2c->err = 0; reinit_completion(&gi2c->done); @@ -475,28 +678,17 @@ static int geni_i2c_xfer(struct i2c_adapter *adap, } qcom_geni_i2c_conf(gi2c); - for (i = 0; i < num; i++) { - u32 m_param = i < (num - 1) ? STOP_STRETCH : 0; - - m_param |= ((msgs[i].addr << SLV_ADDR_SHFT) & SLV_ADDR_MSK); - - gi2c->cur = &msgs[i]; - if (msgs[i].flags & I2C_M_RD) - ret = geni_i2c_rx_one_msg(gi2c, &msgs[i], m_param); - else - ret = geni_i2c_tx_one_msg(gi2c, &msgs[i], m_param); - if (ret) - break; - } - if (ret == 0) - ret = num; + if (gi2c->gpi_mode) + ret = geni_i2c_gpi_xfer(gi2c, msgs, num); + else + ret = geni_i2c_fifo_xfer(gi2c, msgs, num); pm_runtime_mark_last_busy(gi2c->se.dev); pm_runtime_put_autosuspend(gi2c->se.dev); gi2c->cur = NULL; gi2c->err = 0; - return ret; + return num; } static u32 geni_i2c_func(struct i2c_adapter *adap) @@ -517,11 +709,50 @@ static const struct acpi_device_id geni_i2c_acpi_match[] = { MODULE_DEVICE_TABLE(acpi, geni_i2c_acpi_match); #endif +static void release_gpi_dma(struct geni_i2c_dev *gi2c) +{ + if (gi2c->rx_c) + dma_release_channel(gi2c->rx_c); + + if (gi2c->tx_c) + dma_release_channel(gi2c->tx_c); +} + +static int setup_gpi_dma(struct geni_i2c_dev *gi2c) +{ + int ret; + + geni_se_select_mode(&gi2c->se, GENI_GPI_DMA); + gi2c->tx_c = dma_request_chan(gi2c->se.dev, "tx"); + if (IS_ERR(gi2c->tx_c)) { + ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->tx_c), + "Failed to get tx DMA ch\n"); + if (ret < 0) + goto err_tx; + } + + gi2c->rx_c = dma_request_chan(gi2c->se.dev, "rx"); + if (IS_ERR(gi2c->rx_c)) { + ret = dev_err_probe(gi2c->se.dev, PTR_ERR(gi2c->rx_c), + "Failed to get rx DMA ch\n"); + if (ret < 0) + goto err_rx; + } + + dev_dbg(gi2c->se.dev, "Grabbed GPI dma channels\n"); + return 0; + +err_rx: + dma_release_channel(gi2c->tx_c); +err_tx: + return ret; +} + static int geni_i2c_probe(struct platform_device *pdev) { struct geni_i2c_dev *gi2c; struct resource *res; - u32 proto, tx_depth; + u32 proto, tx_depth, fifo_disable; int ret; struct device *dev = &pdev->dev; @@ -601,27 +832,43 @@ static int geni_i2c_probe(struct platform_device *pdev) return ret; } proto = geni_se_read_proto(&gi2c->se); - tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se); if (proto != GENI_SE_I2C) { dev_err(dev, "Invalid proto %d\n", proto); geni_se_resources_off(&gi2c->se); return -ENXIO; } - gi2c->tx_wm = tx_depth - 1; - geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth); - geni_se_config_packing(&gi2c->se, BITS_PER_BYTE, PACKING_BYTES_PW, - true, true, true); + + fifo_disable = readl_relaxed(gi2c->se.base + GENI_IF_DISABLE_RO) & FIFO_IF_DISABLE; + if (fifo_disable) { + /* FIFO is disabled, so we can only use GPI DMA */ + gi2c->gpi_mode = true; + ret = setup_gpi_dma(gi2c); + if (ret) { + dev_err(dev, "Failed to setup GPI DMA mode:%d ret\n", ret); + return ret; + } + + dev_dbg(dev, "Using GPI DMA mode for I2C\n"); + } else { + gi2c->gpi_mode = false; + tx_depth = geni_se_get_tx_fifo_depth(&gi2c->se); + gi2c->tx_wm = tx_depth - 1; + geni_se_init(&gi2c->se, gi2c->tx_wm, tx_depth); + geni_se_config_packing(&gi2c->se, BITS_PER_BYTE, + PACKING_BYTES_PW, true, true, true); + + dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth); + } + ret = geni_se_resources_off(&gi2c->se); if (ret) { dev_err(dev, "Error turning off resources %d\n", ret); - return ret; + goto err_dma; } ret = geni_icc_disable(&gi2c->se); if (ret) - return ret; - - dev_dbg(dev, "i2c fifo/se-dma mode. fifo depth:%d\n", tx_depth); + goto err_dma; gi2c->suspended = 1; pm_runtime_set_suspended(gi2c->se.dev); @@ -633,12 +880,16 @@ static int geni_i2c_probe(struct platform_device *pdev) if (ret) { dev_err(dev, "Error adding i2c adapter %d\n", ret); pm_runtime_disable(gi2c->se.dev); - return ret; + goto err_dma; } dev_dbg(dev, "Geni-I2C adaptor successfully added\n"); return 0; + +err_dma: + release_gpi_dma(gi2c); + return ret; } static int geni_i2c_remove(struct platform_device *pdev) @@ -646,6 +897,7 @@ static int geni_i2c_remove(struct platform_device *pdev) struct geni_i2c_dev *gi2c = platform_get_drvdata(pdev); i2c_del_adapter(&gi2c->adap); + release_gpi_dma(gi2c); pm_runtime_disable(gi2c->se.dev); return 0; } |