On 11/14/2014 04:37 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 | 113 > ++++++++++++++------- > 3 files changed, 87 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 1546c2b..89739a1 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); > }
My arm gcc-4.7.2 spits this warnings, I'll initialize ctrl to 0. > drivers/net/can/c_can/c_can_platform.c: In function > 'c_can_hw_raminit_wait_syscon': > drivers/net/can/c_can/c_can_platform.c:92:17: warning: 'ctrl' may be used > uninitialized in this function [-Wuninitialized] > drivers/net/can/c_can/c_can_platform.c: In function 'c_can_hw_raminit_syscon': > drivers/net/can/c_can/c_can_platform.c:115:7: warning: 'ctrl' is used > uninitialized in this function [-Wuninitialized] Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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