From 6197aa65c4905532943155d03031ba0f3a4b2a3b Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 20 Jan 2017 11:03:03 +0100 Subject: [PATCH] clk: renesas: cpg-mssr: Add support for reset control MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add optional support for the Reset Control feature of the Renesas Clock Pulse Generator / Module Standby and Software Reset module on R-Car Gen2, R-Car Gen3, and RZ/G1 SoCs. This allows to reset SoC devices using the Reset Controller API. Signed-off-by: Geert Uytterhoeven Acked-by: Philipp Zabel Acked-by: Stephen Boyd Reviewed-by: Niklas Söderlund --- drivers/clk/renesas/renesas-cpg-mssr.c | 126 +++++++++++++++++++++++++ 1 file changed, 126 insertions(+) diff --git a/drivers/clk/renesas/renesas-cpg-mssr.c b/drivers/clk/renesas/renesas-cpg-mssr.c index f1161a585c57..eadcbd43ff88 100644 --- a/drivers/clk/renesas/renesas-cpg-mssr.c +++ b/drivers/clk/renesas/renesas-cpg-mssr.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -25,6 +26,7 @@ #include #include #include +#include #include #include @@ -96,6 +98,7 @@ static const u16 srcr[] = { /** * Clock Pulse Generator / Module Standby and Software Reset Private Data * + * @rcdev: Optional reset controller entity * @dev: CPG/MSSR device * @base: CPG/MSSR register block base address * @rmw_lock: protects RMW register accesses @@ -105,6 +108,9 @@ static const u16 srcr[] = { * @last_dt_core_clk: ID of the last Core Clock exported to DT */ struct cpg_mssr_priv { +#ifdef CONFIG_RESET_CONTROLLER + struct reset_controller_dev rcdev; +#endif struct device *dev; void __iomem *base; spinlock_t rmw_lock; @@ -494,6 +500,122 @@ static int __init cpg_mssr_add_clk_domain(struct device *dev, return 0; } +#ifdef CONFIG_RESET_CONTROLLER + +#define rcdev_to_priv(x) container_of(x, struct cpg_mssr_priv, rcdev) + +static int cpg_mssr_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct cpg_mssr_priv *priv = rcdev_to_priv(rcdev); + unsigned int reg = id / 32; + unsigned int bit = id % 32; + u32 bitmask = BIT(bit); + unsigned long flags; + u32 value; + + dev_dbg(priv->dev, "reset %u%02u\n", reg, bit); + + /* Reset module */ + spin_lock_irqsave(&priv->rmw_lock, flags); + value = readl(priv->base + SRCR(reg)); + value |= bitmask; + writel(value, priv->base + SRCR(reg)); + spin_unlock_irqrestore(&priv->rmw_lock, flags); + + /* Wait for at least one cycle of the RCLK clock (@ ca. 32 kHz) */ + udelay(35); + + /* Release module from reset state */ + writel(bitmask, priv->base + SRSTCLR(reg)); + + return 0; +} + +static int cpg_mssr_assert(struct reset_controller_dev *rcdev, unsigned long id) +{ + struct cpg_mssr_priv *priv = rcdev_to_priv(rcdev); + unsigned int reg = id / 32; + unsigned int bit = id % 32; + u32 bitmask = BIT(bit); + unsigned long flags; + u32 value; + + dev_dbg(priv->dev, "assert %u%02u\n", reg, bit); + + spin_lock_irqsave(&priv->rmw_lock, flags); + value = readl(priv->base + SRCR(reg)); + value |= bitmask; + writel(value, priv->base + SRCR(reg)); + spin_unlock_irqrestore(&priv->rmw_lock, flags); + return 0; +} + +static int cpg_mssr_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct cpg_mssr_priv *priv = rcdev_to_priv(rcdev); + unsigned int reg = id / 32; + unsigned int bit = id % 32; + u32 bitmask = BIT(bit); + + dev_dbg(priv->dev, "deassert %u%02u\n", reg, bit); + + writel(bitmask, priv->base + SRSTCLR(reg)); + return 0; +} + +static int cpg_mssr_status(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct cpg_mssr_priv *priv = rcdev_to_priv(rcdev); + unsigned int reg = id / 32; + unsigned int bit = id % 32; + u32 bitmask = BIT(bit); + + return !!(readl(priv->base + SRCR(reg)) & bitmask); +} + +static const struct reset_control_ops cpg_mssr_reset_ops = { + .reset = cpg_mssr_reset, + .assert = cpg_mssr_assert, + .deassert = cpg_mssr_deassert, + .status = cpg_mssr_status, +}; + +static int cpg_mssr_reset_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *reset_spec) +{ + struct cpg_mssr_priv *priv = rcdev_to_priv(rcdev); + unsigned int unpacked = reset_spec->args[0]; + unsigned int idx = MOD_CLK_PACK(unpacked); + + if (unpacked % 100 > 31 || idx >= rcdev->nr_resets) { + dev_err(priv->dev, "Invalid reset index %u\n", unpacked); + return -EINVAL; + } + + return idx; +} + +static int cpg_mssr_reset_controller_register(struct cpg_mssr_priv *priv) +{ + priv->rcdev.ops = &cpg_mssr_reset_ops; + priv->rcdev.of_node = priv->dev->of_node; + priv->rcdev.of_reset_n_cells = 1; + priv->rcdev.of_xlate = cpg_mssr_reset_xlate; + priv->rcdev.nr_resets = priv->num_mod_clks; + return devm_reset_controller_register(priv->dev, &priv->rcdev); +} + +#else /* !CONFIG_RESET_CONTROLLER */ +static inline int cpg_mssr_reset_controller_register(struct cpg_mssr_priv *priv) +{ + return 0; +} +#endif /* !CONFIG_RESET_CONTROLLER */ + + static const struct of_device_id cpg_mssr_match[] = { #ifdef CONFIG_ARCH_R8A7743 { @@ -591,6 +713,10 @@ static int __init cpg_mssr_probe(struct platform_device *pdev) if (error) return error; + error = cpg_mssr_reset_controller_register(priv); + if (error) + return error; + return 0; }