On 11/07/2014 03:49 PM, Roger Quadros wrote: > Some TI SoCs like DRA7 have a RAMINIT register specification > different from the other AMxx SoCs and as expected by the > existing driver. > > To add more insanity, this register is shared with other > IPs like DSS, PCIe and PWM. > > Provides a more generic mechanism to specify the RAMINIT > register location and START/DONE bit position and use the > syscon/regmap framework to access the register. > > Signed-off-by: Roger Quadros <[email protected]> > --- > .../devicetree/bindings/net/can/c_can.txt | 3 + > drivers/net/can/c_can/c_can.h | 11 +- > drivers/net/can/c_can/c_can_platform.c | 112 > ++++++++++++++------- > 3 files changed, 86 insertions(+), 40 deletions(-) > > diff --git a/Documentation/devicetree/bindings/net/can/c_can.txt > b/Documentation/devicetree/bindings/net/can/c_can.txt > index 8f1ae81..a3ca3ee 100644 > --- a/Documentation/devicetree/bindings/net/can/c_can.txt > +++ b/Documentation/devicetree/bindings/net/can/c_can.txt > @@ -12,6 +12,9 @@ Required properties: > Optional properties: > - ti,hwmods : Must be "d_can<n>" or "c_can<n>", n being the > instance number > +- syscon-raminit : Handle to system control region that contains the > + RAMINIT register, register offset to the RAMINIT > + register and the CAN instance number (0 offset). > > Note: "ti,hwmods" field is used to fetch the base address and irq > resources from TI, omap hwmod data base during device registration. > diff --git a/drivers/net/can/c_can/c_can.h b/drivers/net/can/c_can/c_can.h > index 3c305a1..0e17c7b 100644 > --- a/drivers/net/can/c_can/c_can.h > +++ b/drivers/net/can/c_can/c_can.h > @@ -179,6 +179,14 @@ struct c_can_driver_data { > bool raminit_pulse; /* If set, sets and clears START bit (pulse) */ > }; > > +/* Out of band RAMINIT register access via syscon regmap */ > +struct c_can_raminit { > + struct regmap *syscon; /* for raminit ctrl. reg. access */ > + unsigned int reg; /* register index within syscon */ > + u8 start_bit; > + u8 done_bit; > +}; > + > /* c_can private data structure */ > struct c_can_priv { > struct can_priv can; /* must be the first member */ > @@ -196,8 +204,7 @@ struct c_can_priv { > const u16 *regs; > void *priv; /* for board-specific data */ > enum c_can_dev_id type; > - u32 __iomem *raminit_ctrlreg; > - int instance; > + struct c_can_raminit raminit_sys; /* RAMINIT via syscon regmap */ > void (*raminit) (const struct c_can_priv *priv, bool enable); > u32 comm_rcv_high; > u32 rxmasked; > diff --git a/drivers/net/can/c_can/c_can_platform.c > b/drivers/net/can/c_can/c_can_platform.c > index 20deb67..3776483 100644 > --- a/drivers/net/can/c_can/c_can_platform.c > +++ b/drivers/net/can/c_can/c_can_platform.c > @@ -32,14 +32,13 @@ > #include <linux/clk.h> > #include <linux/of.h> > #include <linux/of_device.h> > +#include <linux/mfd/syscon.h> > +#include <linux/regmap.h> > > #include <linux/can/dev.h> > > #include "c_can.h" > > -#define CAN_RAMINIT_START_MASK(i) (0x001 << (i)) > -#define CAN_RAMINIT_DONE_MASK(i) (0x100 << (i)) > -#define CAN_RAMINIT_ALL_MASK(i) (0x101 << (i)) > #define DCAN_RAM_INIT_BIT (1 << 3) > static DEFINE_SPINLOCK(raminit_lock); > /* > @@ -72,47 +71,61 @@ static void c_can_plat_write_reg_aligned_to_32bit(const > struct c_can_priv *priv, > writew(val, priv->base + 2 * priv->regs[index]); > } > > -static void c_can_hw_raminit_wait_ti(const struct c_can_priv *priv, u32 mask, > - u32 val) > +static void c_can_hw_raminit_wait_syscon(const struct c_can_priv *priv, > + u32 mask, u32 val) > { > int timeout = 0; > + const struct c_can_raminit *raminit = &priv->raminit_sys; > + u32 ctrl; > + > /* We look only at the bits of our instance. */ > val &= mask; > - while ((readl(priv->raminit_ctrlreg) & mask) != val) { > + do { > udelay(1); > timeout++; > > + regmap_read(raminit->syscon, raminit->reg, &ctrl); > if (timeout == 1000) { > dev_err(&priv->dev->dev, "%s: time out\n", __func__); > break; > } > - } > + } while ((ctrl & mask) != val); > } > > -static void c_can_hw_raminit_ti(const struct c_can_priv *priv, bool enable) > +static void c_can_hw_raminit_syscon(const struct c_can_priv *priv, bool > enable) > { > - u32 mask = CAN_RAMINIT_ALL_MASK(priv->instance); > + u32 mask; > u32 ctrl; > + const struct c_can_raminit *raminit = &priv->raminit_sys; > + u8 start_bit, done_bit; > + > + start_bit = raminit->start_bit; > + done_bit = raminit->done_bit; > > spin_lock(&raminit_lock); > > - ctrl = readl(priv->raminit_ctrlreg); > + mask = 1 << start_bit | 1 << done_bit; > + regmap_read(raminit->syscon, raminit->reg, &ctrl); > + > /* We clear the done and start bit first. The start bit is > * looking at the 0 -> transition, but is not self clearing; > * And we clear the init done bit as well. > + * NOTE: DONE must be written with 1 to clear it. > */ > - ctrl &= ~CAN_RAMINIT_START_MASK(priv->instance); > - ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance); > - writel(ctrl, priv->raminit_ctrlreg); > - ctrl &= ~CAN_RAMINIT_DONE_MASK(priv->instance); > - c_can_hw_raminit_wait_ti(priv, mask, ctrl); > + ctrl &= ~(1 << start_bit); > + ctrl |= 1 << done_bit; > + regmap_write(raminit->syscon, raminit->reg, ctrl); > + > + ctrl &= ~(1 << done_bit); > + c_can_hw_raminit_wait_syscon(priv, mask, ctrl); > > if (enable) { > /* Set start bit and wait for the done bit. */ > - ctrl |= CAN_RAMINIT_START_MASK(priv->instance); > - writel(ctrl, priv->raminit_ctrlreg); > - ctrl |= CAN_RAMINIT_DONE_MASK(priv->instance); > - c_can_hw_raminit_wait_ti(priv, mask, ctrl); > + ctrl |= 1 << start_bit; > + regmap_write(raminit->syscon, raminit->reg, ctrl); > + > + ctrl |= 1 << done_bit; > + c_can_hw_raminit_wait_syscon(priv, mask, ctrl); > } > spin_unlock(&raminit_lock); > } > @@ -206,10 +219,11 @@ static int c_can_plat_probe(struct platform_device > *pdev) > struct net_device *dev; > struct c_can_priv *priv; > const struct of_device_id *match; > - struct resource *mem, *res; > + struct resource *mem; > int irq; > struct clk *clk; > const struct c_can_driver_data *drvdata; > + struct device_node *np = pdev->dev.of_node; > > match = of_match_device(c_can_of_table, &pdev->dev); > if (match) { > @@ -278,27 +292,49 @@ static int c_can_plat_probe(struct platform_device > *pdev) > priv->read_reg32 = d_can_plat_read_reg32; > priv->write_reg32 = d_can_plat_write_reg32; > > - if (pdev->dev.of_node) > - priv->instance = of_alias_get_id(pdev->dev.of_node, > "d_can"); > - else > - priv->instance = pdev->id; > - > - res = platform_get_resource(pdev, IORESOURCE_MEM, 1); > - /* Not all D_CAN modules have a separate register for the D_CAN > - * RAM initialization. Use default RAM init bit in D_CAN module > - * if not specified in DT. > + /* Check if we need custom RAMINIT via syscon. Mostly for TI > + * platforms. Only supported with DT boot. > */ > - if (!res) { > + if (np && of_property_read_bool(np, "syscon-raminit")) { > + u32 id; > + struct c_can_raminit *raminit = &priv->raminit_sys; > + > + ret = -EINVAL; > + raminit->syscon = syscon_regmap_lookup_by_phandle(np, > + > "syscon-raminit");
You should return PTR_ERR() here, as it it might be -EPROBE_DEFER
> + if (IS_ERR(raminit->syscon)) {
> + dev_err(&pdev->dev,
> + "couldn't get syscon regmap for
> RAMINIT\n");
> + goto exit_free_device;
> + }
...and maybe remove this error message completely.
regards,
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
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