diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-hisi.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-hisi.c | 73 |
1 files changed, 56 insertions, 17 deletions
diff --git a/drivers/i2c/busses/i2c-hisi.c b/drivers/i2c/busses/i2c-hisi.c index acf394812061..4b735ad9e193 100644 --- a/drivers/i2c/busses/i2c-hisi.c +++ b/drivers/i2c/busses/i2c-hisi.c @@ -7,6 +7,7 @@ #include <linux/bits.h> #include <linux/bitfield.h> +#include <linux/clk.h> #include <linux/completion.h> #include <linux/i2c.h> #include <linux/interrupt.h> @@ -15,6 +16,7 @@ #include <linux/mod_devicetable.h> #include <linux/platform_device.h> #include <linux/property.h> +#include <linux/units.h> #define HISI_I2C_FRAME_CTRL 0x0000 #define HISI_I2C_FRAME_CTRL_SPEED_MODE GENMASK(1, 0) @@ -55,6 +57,8 @@ #define HISI_I2C_FS_SPK_LEN_CNT GENMASK(7, 0) #define HISI_I2C_HS_SPK_LEN 0x003c #define HISI_I2C_HS_SPK_LEN_CNT GENMASK(7, 0) +#define HISI_I2C_TX_INT_CLR 0x0040 +#define HISI_I2C_TX_AEMPTY_INT BIT(0) #define HISI_I2C_INT_MSTAT 0x0044 #define HISI_I2C_INT_CLR 0x0048 #define HISI_I2C_INT_MASK 0x004C @@ -80,8 +84,6 @@ #define HISI_I2C_TX_F_AE_THRESH 1 #define HISI_I2C_RX_F_AF_THRESH 60 -#define HZ_PER_KHZ 1000 - #define NSEC_TO_CYCLES(ns, clk_rate_khz) \ DIV_ROUND_UP_ULL((clk_rate_khz) * (ns), NSEC_PER_MSEC) @@ -89,6 +91,7 @@ struct hisi_i2c_controller { struct i2c_adapter adapter; void __iomem *iobase; struct device *dev; + struct clk *clk; int irq; /* Intermediates for recording the transfer process */ @@ -123,6 +126,11 @@ static void hisi_i2c_clear_int(struct hisi_i2c_controller *ctlr, u32 mask) writel_relaxed(mask, ctlr->iobase + HISI_I2C_INT_CLR); } +static void hisi_i2c_clear_tx_int(struct hisi_i2c_controller *ctlr, u32 mask) +{ + writel_relaxed(mask, ctlr->iobase + HISI_I2C_TX_INT_CLR); +} + static void hisi_i2c_handle_errors(struct hisi_i2c_controller *ctlr) { u32 int_err = ctlr->xfer_err, reg; @@ -167,6 +175,7 @@ static int hisi_i2c_start_xfer(struct hisi_i2c_controller *ctlr) writel(reg, ctlr->iobase + HISI_I2C_FIFO_CTRL); hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL); + hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT); hisi_i2c_enable_int(ctlr, HISI_I2C_INT_ALL); return 0; @@ -188,8 +197,8 @@ static void hisi_i2c_reset_xfer(struct hisi_i2c_controller *ctlr) * wait for the transfer done. The major transfer process is performed * in the IRQ handler. */ -static int hisi_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, - int num) +static int hisi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) { struct hisi_i2c_controller *ctlr = i2c_get_adapdata(adap); DECLARE_COMPLETION_ONSTACK(done); @@ -227,8 +236,8 @@ static u32 hisi_i2c_functionality(struct i2c_adapter *adap) } static const struct i2c_algorithm hisi_i2c_algo = { - .master_xfer = hisi_i2c_master_xfer, - .functionality = hisi_i2c_functionality, + .xfer = hisi_i2c_xfer, + .functionality = hisi_i2c_functionality, }; static int hisi_i2c_read_rx_fifo(struct hisi_i2c_controller *ctlr) @@ -265,7 +274,7 @@ static int hisi_i2c_read_rx_fifo(struct hisi_i2c_controller *ctlr) static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr) { - int max_write = HISI_I2C_TX_FIFO_DEPTH; + int max_write = HISI_I2C_TX_FIFO_DEPTH - HISI_I2C_TX_F_AE_THRESH; bool need_restart = false, last_msg; struct i2c_msg *cur_msg; u32 cmd, fifo_state; @@ -315,6 +324,15 @@ static void hisi_i2c_xfer_msg(struct hisi_i2c_controller *ctlr) max_write == 0) break; } + + /* + * Disable the TX_EMPTY interrupt after finishing all the messages to + * avoid overwhelming the CPU. + */ + if (ctlr->msg_tx_idx == ctlr->msg_num) + hisi_i2c_disable_int(ctlr, HISI_I2C_INT_TX_EMPTY); + + hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT); } static irqreturn_t hisi_i2c_irq(int irq, void *context) @@ -322,6 +340,14 @@ static irqreturn_t hisi_i2c_irq(int irq, void *context) struct hisi_i2c_controller *ctlr = context; u32 int_stat; + /* + * Don't handle the interrupt if cltr->completion is NULL. We may + * reach here because the interrupt is spurious or the transfer is + * started by another port (e.g. firmware) rather than us. + */ + if (!ctlr->completion) + return IRQ_NONE; + int_stat = readl(ctlr->iobase + HISI_I2C_INT_MSTAT); hisi_i2c_clear_int(ctlr, int_stat); if (!(int_stat & HISI_I2C_INT_ALL)) @@ -340,9 +366,14 @@ static irqreturn_t hisi_i2c_irq(int irq, void *context) hisi_i2c_read_rx_fifo(ctlr); out: - if (int_stat & HISI_I2C_INT_TRANS_CPLT || ctlr->xfer_err) { + /* + * Only use TRANS_CPLT to indicate the completion. On error cases we'll + * get two interrupts, INT_ERR first then TRANS_CPLT. + */ + if (int_stat & HISI_I2C_INT_TRANS_CPLT) { hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL); hisi_i2c_clear_int(ctlr, HISI_I2C_INT_ALL); + hisi_i2c_clear_tx_int(ctlr, HISI_I2C_TX_AEMPTY_INT); complete(ctlr->completion); } @@ -450,15 +481,16 @@ static int hisi_i2c_probe(struct platform_device *pdev) hisi_i2c_disable_int(ctlr, HISI_I2C_INT_ALL); ret = devm_request_irq(dev, ctlr->irq, hisi_i2c_irq, 0, "hisi-i2c", ctlr); - if (ret) { - dev_err(dev, "failed to request irq handler, ret = %d\n", ret); - return ret; - } - - ret = device_property_read_u64(dev, "clk_rate", &clk_rate_hz); - if (ret) { - dev_err(dev, "failed to get clock frequency, ret = %d\n", ret); - return ret; + if (ret) + return dev_err_probe(dev, ret, "failed to request irq handler\n"); + + ctlr->clk = devm_clk_get_optional_enabled(&pdev->dev, NULL); + if (IS_ERR_OR_NULL(ctlr->clk)) { + ret = device_property_read_u64(dev, "clk_rate", &clk_rate_hz); + if (ret) + return dev_err_probe(dev, ret, "failed to get clock frequency\n"); + } else { + clk_rate_hz = clk_get_rate(ctlr->clk); } ctlr->clk_rate_khz = DIV_ROUND_UP_ULL(clk_rate_hz, HZ_PER_KHZ); @@ -490,11 +522,18 @@ static const struct acpi_device_id hisi_i2c_acpi_ids[] = { }; MODULE_DEVICE_TABLE(acpi, hisi_i2c_acpi_ids); +static const struct of_device_id hisi_i2c_dts_ids[] = { + { .compatible = "hisilicon,ascend910-i2c", }, + { } +}; +MODULE_DEVICE_TABLE(of, hisi_i2c_dts_ids); + static struct platform_driver hisi_i2c_driver = { .probe = hisi_i2c_probe, .driver = { .name = "hisi-i2c", .acpi_match_table = hisi_i2c_acpi_ids, + .of_match_table = hisi_i2c_dts_ids, }, }; module_platform_driver(hisi_i2c_driver); |