diff options
author | Serge Semin <Sergey.Semin@baikalelectronics.ru> | 2020-05-28 12:33:18 +0300 |
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committer | Wolfram Sang <wsa@kernel.org> | 2020-05-30 23:02:22 +0200 |
commit | 0daede80f870025141cbb16e6a826d5e7f43f4a5 (patch) | |
tree | 668a5fd899c4c73173d1da8a1919528d0133ac79 /drivers/i2c/busses/i2c-designware-master.c | |
parent | c615f5c65f622fb62df17d58485f46a544d6e07a (diff) | |
download | linux-0daede80f870025141cbb16e6a826d5e7f43f4a5.tar.bz2 |
i2c: designware: Convert driver to using regmap API
Seeing the DW I2C driver is using flags-based accessors with two
conditional clauses it would be better to replace them with the regmap
API IO methods and to initialize the regmap object with read/write
callbacks specific to the controller registers map implementation. This
will be also handy for the drivers with non-standard registers mapping
(like an embedded into the Baikal-T1 System Controller DW I2C block, which
glue-driver is a part of this series).
As before the driver tries to detect the mapping setup at probe stage and
creates a regmap object accordingly, which will be used by the rest of the
code to correctly access the controller registers. In two places it was
appropriate to convert the hand-written read-modify-write and
read-poll-loop design patterns to the corresponding regmap API
ready-to-use methods.
Note the regmap IO methods return value is checked only at the probe
stage. The rest of the code won't do this because basically we have
MMIO-based regmap so non of the read/write methods can fail (this also
won't be needed for the Baikal-T1-specific I2C controller).
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[wsa: fix type of 'rx_valid' and remove outdated kdoc var description]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-master.c')
-rw-r--r-- | drivers/i2c/busses/i2c-designware-master.c | 127 |
1 files changed, 70 insertions, 57 deletions
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index 95eeec53c744..d6425ad6e6a3 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -18,6 +18,7 @@ #include <linux/io.h> #include <linux/module.h> #include <linux/pm_runtime.h> +#include <linux/regmap.h> #include <linux/reset.h> #include "i2c-designware-core.h" @@ -25,11 +26,11 @@ static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev) { /* Configure Tx/Rx FIFO threshold levels */ - dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL); - dw_writel(dev, 0, DW_IC_RX_TL); + regmap_write(dev->map, DW_IC_TX_TL, dev->tx_fifo_depth / 2); + regmap_write(dev->map, DW_IC_RX_TL, 0); /* Configure the I2C master */ - dw_writel(dev, dev->master_cfg, DW_IC_CON); + regmap_write(dev->map, DW_IC_CON, dev->master_cfg); } static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) @@ -44,8 +45,11 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) ret = i2c_dw_acquire_lock(dev); if (ret) return ret; - comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1); + + ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &comp_param1); i2c_dw_release_lock(dev); + if (ret) + return ret; /* Set standard and fast speed dividers for high/low periods */ sda_falling_time = t->sda_fall_ns ?: 300; /* ns */ @@ -187,22 +191,22 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev) __i2c_dw_disable(dev); /* Write standard speed timing parameters */ - dw_writel(dev, dev->ss_hcnt, DW_IC_SS_SCL_HCNT); - dw_writel(dev, dev->ss_lcnt, DW_IC_SS_SCL_LCNT); + regmap_write(dev->map, DW_IC_SS_SCL_HCNT, dev->ss_hcnt); + regmap_write(dev->map, DW_IC_SS_SCL_LCNT, dev->ss_lcnt); /* Write fast mode/fast mode plus timing parameters */ - dw_writel(dev, dev->fs_hcnt, DW_IC_FS_SCL_HCNT); - dw_writel(dev, dev->fs_lcnt, DW_IC_FS_SCL_LCNT); + regmap_write(dev->map, DW_IC_FS_SCL_HCNT, dev->fs_hcnt); + regmap_write(dev->map, DW_IC_FS_SCL_LCNT, dev->fs_lcnt); /* Write high speed timing parameters if supported */ if (dev->hs_hcnt && dev->hs_lcnt) { - dw_writel(dev, dev->hs_hcnt, DW_IC_HS_SCL_HCNT); - dw_writel(dev, dev->hs_lcnt, DW_IC_HS_SCL_LCNT); + regmap_write(dev->map, DW_IC_HS_SCL_HCNT, dev->hs_hcnt); + regmap_write(dev->map, DW_IC_HS_SCL_LCNT, dev->hs_lcnt); } /* Write SDA hold time if supported */ if (dev->sda_hold_time) - dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD); + regmap_write(dev->map, DW_IC_SDA_HOLD, dev->sda_hold_time); i2c_dw_configure_fifo_master(dev); i2c_dw_release_lock(dev); @@ -213,15 +217,15 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev) static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; - u32 ic_con, ic_tar = 0; + u32 ic_con = 0, ic_tar = 0; + u32 dummy; /* Disable the adapter */ __i2c_dw_disable(dev); /* If the slave address is ten bit address, enable 10BITADDR */ - ic_con = dw_readl(dev, DW_IC_CON); if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) { - ic_con |= DW_IC_CON_10BITADDR_MASTER; + ic_con = DW_IC_CON_10BITADDR_MASTER; /* * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing * mode has to be enabled via bit 12 of IC_TAR register. @@ -229,17 +233,17 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) * detected from registers. */ ic_tar = DW_IC_TAR_10BITADDR_MASTER; - } else { - ic_con &= ~DW_IC_CON_10BITADDR_MASTER; } - dw_writel(dev, ic_con, DW_IC_CON); + regmap_update_bits(dev->map, DW_IC_CON, DW_IC_CON_10BITADDR_MASTER, + ic_con); /* * Set the slave (target) address and enable 10-bit addressing mode * if applicable. */ - dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR); + regmap_write(dev->map, DW_IC_TAR, + msgs[dev->msg_write_idx].addr | ic_tar); /* Enforce disabled interrupts (due to HW issues) */ i2c_dw_disable_int(dev); @@ -248,11 +252,11 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) __i2c_dw_enable(dev); /* Dummy read to avoid the register getting stuck on Bay Trail */ - dw_readl(dev, DW_IC_ENABLE_STATUS); + regmap_read(dev->map, DW_IC_ENABLE_STATUS, &dummy); /* Clear and enable interrupts */ - dw_readl(dev, DW_IC_CLR_INTR); - dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK); + regmap_read(dev->map, DW_IC_CLR_INTR, &dummy); + regmap_write(dev->map, DW_IC_INTR_MASK, DW_IC_INTR_MASTER_MASK); } /* @@ -271,6 +275,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) u32 buf_len = dev->tx_buf_len; u8 *buf = dev->tx_buf; bool need_restart = false; + unsigned int flr; intr_mask = DW_IC_INTR_MASTER_MASK; @@ -303,8 +308,11 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) need_restart = true; } - tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR); - rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR); + regmap_read(dev->map, DW_IC_TXFLR, &flr); + tx_limit = dev->tx_fifo_depth - flr; + + regmap_read(dev->map, DW_IC_RXFLR, &flr); + rx_limit = dev->rx_fifo_depth - flr; while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) { u32 cmd = 0; @@ -337,11 +345,14 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) if (dev->rx_outstanding >= dev->rx_fifo_depth) break; - dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD); + regmap_write(dev->map, DW_IC_DATA_CMD, + cmd | 0x100); rx_limit--; dev->rx_outstanding++; - } else - dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD); + } else { + regmap_write(dev->map, DW_IC_DATA_CMD, + cmd | *buf++); + } tx_limit--; buf_len--; } @@ -371,7 +382,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) if (dev->msg_err) intr_mask = 0; - dw_writel(dev, intr_mask, DW_IC_INTR_MASK); + regmap_write(dev->map, DW_IC_INTR_MASK, intr_mask); } static u8 @@ -396,10 +407,10 @@ static void i2c_dw_read(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; - int rx_valid; + unsigned int rx_valid; for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) { - u32 len; + u32 len, tmp; u8 *buf; if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD)) @@ -413,18 +424,18 @@ i2c_dw_read(struct dw_i2c_dev *dev) buf = dev->rx_buf; } - rx_valid = dw_readl(dev, DW_IC_RXFLR); + regmap_read(dev->map, DW_IC_RXFLR, &rx_valid); for (; len > 0 && rx_valid > 0; len--, rx_valid--) { u32 flags = msgs[dev->msg_read_idx].flags; - *buf = dw_readl(dev, DW_IC_DATA_CMD); + regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); /* Ensure length byte is a valid value */ if (flags & I2C_M_RECV_LEN && - *buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) { - len = i2c_dw_recv_len(dev, *buf); + tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) { + len = i2c_dw_recv_len(dev, tmp); } - buf++; + *buf++ = tmp; dev->rx_outstanding--; } @@ -542,7 +553,7 @@ static const struct i2c_adapter_quirks i2c_dw_quirks = { static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev) { - u32 stat; + u32 stat, dummy; /* * The IC_INTR_STAT register just indicates "enabled" interrupts. @@ -550,47 +561,47 @@ static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev) * in the IC_RAW_INTR_STAT register. * * That is, - * stat = dw_readl(IC_INTR_STAT); + * stat = readl(IC_INTR_STAT); * equals to, - * stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK); + * stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK); * * The raw version might be useful for debugging purposes. */ - stat = dw_readl(dev, DW_IC_INTR_STAT); + regmap_read(dev->map, DW_IC_INTR_STAT, &stat); /* * Do not use the IC_CLR_INTR register to clear interrupts, or * you'll miss some interrupts, triggered during the period from - * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR). + * readl(IC_INTR_STAT) to readl(IC_CLR_INTR). * * Instead, use the separately-prepared IC_CLR_* registers. */ if (stat & DW_IC_INTR_RX_UNDER) - dw_readl(dev, DW_IC_CLR_RX_UNDER); + regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &dummy); if (stat & DW_IC_INTR_RX_OVER) - dw_readl(dev, DW_IC_CLR_RX_OVER); + regmap_read(dev->map, DW_IC_CLR_RX_OVER, &dummy); if (stat & DW_IC_INTR_TX_OVER) - dw_readl(dev, DW_IC_CLR_TX_OVER); + regmap_read(dev->map, DW_IC_CLR_TX_OVER, &dummy); if (stat & DW_IC_INTR_RD_REQ) - dw_readl(dev, DW_IC_CLR_RD_REQ); + regmap_read(dev->map, DW_IC_CLR_RD_REQ, &dummy); if (stat & DW_IC_INTR_TX_ABRT) { /* * The IC_TX_ABRT_SOURCE register is cleared whenever * the IC_CLR_TX_ABRT is read. Preserve it beforehand. */ - dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE); - dw_readl(dev, DW_IC_CLR_TX_ABRT); + regmap_read(dev->map, DW_IC_TX_ABRT_SOURCE, &dev->abort_source); + regmap_read(dev->map, DW_IC_CLR_TX_ABRT, &dummy); } if (stat & DW_IC_INTR_RX_DONE) - dw_readl(dev, DW_IC_CLR_RX_DONE); + regmap_read(dev->map, DW_IC_CLR_RX_DONE, &dummy); if (stat & DW_IC_INTR_ACTIVITY) - dw_readl(dev, DW_IC_CLR_ACTIVITY); + regmap_read(dev->map, DW_IC_CLR_ACTIVITY, &dummy); if (stat & DW_IC_INTR_STOP_DET) - dw_readl(dev, DW_IC_CLR_STOP_DET); + regmap_read(dev->map, DW_IC_CLR_STOP_DET, &dummy); if (stat & DW_IC_INTR_START_DET) - dw_readl(dev, DW_IC_CLR_START_DET); + regmap_read(dev->map, DW_IC_CLR_START_DET, &dummy); if (stat & DW_IC_INTR_GEN_CALL) - dw_readl(dev, DW_IC_CLR_GEN_CALL); + regmap_read(dev->map, DW_IC_CLR_GEN_CALL, &dummy); return stat; } @@ -612,7 +623,7 @@ static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev) * Anytime TX_ABRT is set, the contents of the tx/rx * buffers are flushed. Make sure to skip them. */ - dw_writel(dev, 0, DW_IC_INTR_MASK); + regmap_write(dev->map, DW_IC_INTR_MASK, 0); goto tx_aborted; } @@ -633,9 +644,9 @@ tx_aborted: complete(&dev->cmd_complete); else if (unlikely(dev->flags & ACCESS_INTR_MASK)) { /* Workaround to trigger pending interrupt */ - stat = dw_readl(dev, DW_IC_INTR_MASK); + regmap_read(dev->map, DW_IC_INTR_MASK, &stat); i2c_dw_disable_int(dev); - dw_writel(dev, stat, DW_IC_INTR_MASK); + regmap_write(dev->map, DW_IC_INTR_MASK, stat); } return 0; @@ -646,8 +657,8 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) struct dw_i2c_dev *dev = dev_id; u32 stat, enabled; - enabled = dw_readl(dev, DW_IC_ENABLE); - stat = dw_readl(dev, DW_IC_RAW_INTR_STAT); + regmap_read(dev->map, DW_IC_ENABLE, &enabled); + regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &stat); dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat); if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY)) return IRQ_NONE; @@ -739,7 +750,7 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) dev->disable = i2c_dw_disable; dev->disable_int = i2c_dw_disable_int; - ret = i2c_dw_set_reg_access(dev); + ret = i2c_dw_init_regmap(dev); if (ret) return ret; @@ -747,7 +758,9 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) if (ret) return ret; - i2c_dw_set_fifo_size(dev); + ret = i2c_dw_set_fifo_size(dev); + if (ret) + return ret; ret = dev->init(dev); if (ret) |