diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-at91.c')
-rw-r--r-- | drivers/i2c/busses/i2c-at91.c | 127 |
1 files changed, 78 insertions, 49 deletions
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c index e05a672..87e2f14 100644 --- a/drivers/i2c/busses/i2c-at91.c +++ b/drivers/i2c/busses/i2c-at91.c @@ -31,10 +31,13 @@ #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/platform_data/dma-atmel.h> +#include <linux/pm_runtime.h> +#include <linux/pinctrl/consumer.h> #define DEFAULT_TWI_CLK_HZ 100000 /* max 400 Kbits/s */ #define AT91_I2C_TIMEOUT msecs_to_jiffies(100) /* transfer timeout */ #define AT91_I2C_DMA_THRESHOLD 8 /* enable DMA if transfer size is bigger than this threshold */ +#define AUTOSUSPEND_TIMEOUT 2000 /* AT91 TWI register definitions */ #define AT91_TWI_CR 0x0000 /* Control Register */ @@ -72,7 +75,6 @@ struct at91_twi_pdata { unsigned clk_max_div; unsigned clk_offset; bool has_unre_flag; - bool has_dma_support; struct at_dma_slave dma_slave; }; @@ -481,6 +483,10 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) dev_dbg(&adap->dev, "at91_xfer: processing %d messages:\n", num); + ret = pm_runtime_get_sync(dev->dev); + if (ret < 0) + goto out; + /* * The hardware can handle at most two messages concatenated by a * repeated start via it's internal address feature. @@ -488,18 +494,21 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) if (num > 2) { dev_err(dev->dev, "cannot handle more than two concatenated messages.\n"); - return 0; + ret = 0; + goto out; } else if (num == 2) { int internal_address = 0; int i; if (msg->flags & I2C_M_RD) { dev_err(dev->dev, "first transfer must be write.\n"); - return -EINVAL; + ret = -EINVAL; + goto out; } if (msg->len > 3) { dev_err(dev->dev, "first message size must be <= 3.\n"); - return -EINVAL; + ret = -EINVAL; + goto out; } /* 1st msg is put into the internal address, start with 2nd */ @@ -523,7 +532,12 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num) ret = at91_do_twi_transfer(dev); - return (ret < 0) ? ret : num; + ret = (ret < 0) ? ret : num; +out: + pm_runtime_mark_last_busy(dev->dev); + pm_runtime_put_autosuspend(dev->dev); + + return ret; } static u32 at91_twi_func(struct i2c_adapter *adapter) @@ -541,35 +555,30 @@ static struct at91_twi_pdata at91rm9200_config = { .clk_max_div = 5, .clk_offset = 3, .has_unre_flag = true, - .has_dma_support = false, }; static struct at91_twi_pdata at91sam9261_config = { .clk_max_div = 5, .clk_offset = 4, .has_unre_flag = false, - .has_dma_support = false, }; static struct at91_twi_pdata at91sam9260_config = { .clk_max_div = 7, .clk_offset = 4, .has_unre_flag = false, - .has_dma_support = false, }; static struct at91_twi_pdata at91sam9g20_config = { .clk_max_div = 7, .clk_offset = 4, .has_unre_flag = false, - .has_dma_support = false, }; static struct at91_twi_pdata at91sam9g10_config = { .clk_max_div = 7, .clk_offset = 4, .has_unre_flag = false, - .has_dma_support = false, }; static const struct platform_device_id at91_twi_devtypes[] = { @@ -598,7 +607,6 @@ static struct at91_twi_pdata at91sam9x5_config = { .clk_max_div = 7, .clk_offset = 4, .has_unre_flag = false, - .has_dma_support = true, }; static const struct of_device_id atmel_twi_dt_ids[] = { @@ -627,30 +635,11 @@ static const struct of_device_id atmel_twi_dt_ids[] = { MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids); #endif -static bool filter(struct dma_chan *chan, void *pdata) -{ - struct at91_twi_pdata *sl_pdata = pdata; - struct at_dma_slave *sl; - - if (!sl_pdata) - return false; - - sl = &sl_pdata->dma_slave; - if (sl && (sl->dma_dev == chan->device->dev)) { - chan->private = sl; - return true; - } else { - return false; - } -} - static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) { int ret = 0; - struct at91_twi_pdata *pdata = dev->pdata; struct dma_slave_config slave_config; struct at91_twi_dma *dma = &dev->dma; - dma_cap_mask_t mask; memset(&slave_config, 0, sizeof(slave_config)); slave_config.src_addr = (dma_addr_t)phy_addr + AT91_TWI_RHR; @@ -661,22 +650,17 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) slave_config.dst_maxburst = 1; slave_config.device_fc = false; - dma_cap_zero(mask); - dma_cap_set(DMA_SLAVE, mask); - - dma->chan_tx = dma_request_slave_channel_compat(mask, filter, pdata, - dev->dev, "tx"); - if (!dma->chan_tx) { - dev_err(dev->dev, "can't get a DMA channel for tx\n"); - ret = -EBUSY; + dma->chan_tx = dma_request_slave_channel_reason(dev->dev, "tx"); + if (IS_ERR(dma->chan_tx)) { + ret = PTR_ERR(dma->chan_tx); + dma->chan_tx = NULL; goto error; } - dma->chan_rx = dma_request_slave_channel_compat(mask, filter, pdata, - dev->dev, "rx"); - if (!dma->chan_rx) { - dev_err(dev->dev, "can't get a DMA channel for rx\n"); - ret = -EBUSY; + dma->chan_rx = dma_request_slave_channel_reason(dev->dev, "rx"); + if (IS_ERR(dma->chan_rx)) { + ret = PTR_ERR(dma->chan_rx); + dma->chan_rx = NULL; goto error; } @@ -697,6 +681,7 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) sg_init_table(&dma->sg, 1); dma->buf_mapped = false; dma->xfer_in_progress = false; + dev->use_dma = true; dev_info(dev->dev, "using %s (tx) and %s (rx) for DMA transfers\n", dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx)); @@ -704,7 +689,8 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr) return ret; error: - dev_info(dev->dev, "can't use DMA\n"); + if (ret != -EPROBE_DEFER) + dev_info(dev->dev, "can't use DMA, error %d\n", ret); if (dma->chan_rx) dma_release_channel(dma->chan_rx); if (dma->chan_tx) @@ -772,9 +758,10 @@ static int at91_twi_probe(struct platform_device *pdev) } clk_prepare_enable(dev->clk); - if (dev->pdata->has_dma_support) { - if (at91_twi_configure_dma(dev, phy_addr) == 0) - dev->use_dma = true; + if (dev->dev->of_node) { + rc = at91_twi_configure_dma(dev, phy_addr); + if (rc == -EPROBE_DEFER) + return rc; } rc = of_property_read_u32(dev->dev->of_node, "clock-frequency", @@ -795,11 +782,20 @@ static int at91_twi_probe(struct platform_device *pdev) dev->adapter.timeout = AT91_I2C_TIMEOUT; dev->adapter.dev.of_node = pdev->dev.of_node; + pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT); + pm_runtime_use_autosuspend(dev->dev); + pm_runtime_set_active(dev->dev); + pm_runtime_enable(dev->dev); + rc = i2c_add_numbered_adapter(&dev->adapter); if (rc) { dev_err(dev->dev, "Adapter %s registration failed\n", dev->adapter.name); clk_disable_unprepare(dev->clk); + + pm_runtime_disable(dev->dev); + pm_runtime_set_suspended(dev->dev); + return rc; } @@ -814,6 +810,9 @@ static int at91_twi_remove(struct platform_device *pdev) i2c_del_adapter(&dev->adapter); clk_disable_unprepare(dev->clk); + pm_runtime_disable(dev->dev); + pm_runtime_set_suspended(dev->dev); + return 0; } @@ -823,7 +822,9 @@ static int at91_twi_runtime_suspend(struct device *dev) { struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); - clk_disable(twi_dev->clk); + clk_disable_unprepare(twi_dev->clk); + + pinctrl_pm_select_sleep_state(dev); return 0; } @@ -832,10 +833,38 @@ static int at91_twi_runtime_resume(struct device *dev) { struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); - return clk_enable(twi_dev->clk); + pinctrl_pm_select_default_state(dev); + + return clk_prepare_enable(twi_dev->clk); +} + +static int at91_twi_suspend_noirq(struct device *dev) +{ + if (!pm_runtime_status_suspended(dev)) + at91_twi_runtime_suspend(dev); + + return 0; +} + +static int at91_twi_resume_noirq(struct device *dev) +{ + int ret; + + if (!pm_runtime_status_suspended(dev)) { + ret = at91_twi_runtime_resume(dev); + if (ret) + return ret; + } + + pm_runtime_mark_last_busy(dev); + pm_request_autosuspend(dev); + + return 0; } static const struct dev_pm_ops at91_twi_pm = { + .suspend_noirq = at91_twi_suspend_noirq, + .resume_noirq = at91_twi_resume_noirq, .runtime_suspend = at91_twi_runtime_suspend, .runtime_resume = at91_twi_runtime_resume, }; |