From 0ad7c00057dc1640647c1dc81ccbd009de17a767 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Tue, 26 Nov 2013 10:04:22 -0700 Subject: dma: add channel request API that supports deferred probe dma_request_slave_channel() simply returns NULL whenever DMA channel lookup fails. Lookup could fail for two distinct reasons: a) No DMA specification exists for the channel name. This includes situations where no DMA specifications exist at all, or other general lookup problems. b) A DMA specification does exist, yet the driver for that channel is not yet registered. Case (b) should trigger deferred probe in client drivers. However, since they have no way to differentiate the two situations, it cannot. Implement new function dma_request_slave_channel_reason(), which performs identically to dma_request_slave_channel(), except that it returns an error-pointer rather than NULL, which allows callers to detect when deferred probe should occur. Eventually, all drivers should be converted to this new API, the old API removed, and the new API renamed to the more desirable name. This patch doesn't convert the existing API and all drivers in one go, since some drivers call dma_request_slave_channel() then dma_request_channel() if that fails. That would require either modifying dma_request_channel() in the same way, or adding extra error-handling code to all affected drivers, and there are close to 100 drivers using the other API, rather than just the 15-20 or so that use dma_request_slave_channel(), which might be tenable in a single patch. acpi_dma_request_slave_chan_by_name() doesn't currently implement deferred probe. It should, but this will be addressed later. Acked-by: Dan Williams Signed-off-by: Stephen Warren Signed-off-by: Vinod Koul --- include/linux/dmaengine.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux') diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 41cf0c399288..ed92b30a02fd 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -22,6 +22,7 @@ #define LINUX_DMAENGINE_H #include +#include #include #include #include @@ -1040,6 +1041,8 @@ enum dma_status dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx); void dma_issue_pending_all(void); struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param); +struct dma_chan *dma_request_slave_channel_reason(struct device *dev, + const char *name); struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name); void dma_release_channel(struct dma_chan *chan); #else @@ -1063,6 +1066,11 @@ static inline struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, { return NULL; } +static inline struct dma_chan *dma_request_slave_channel_reason( + struct device *dev, const char *name) +{ + return ERR_PTR(-ENODEV); +} static inline struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name) { -- cgit From 8010dad55a0ab0e829f3733854e5235eef4e2734 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Tue, 26 Nov 2013 12:40:51 -0700 Subject: dma: add dma_get_any_slave_channel(), for use in of_xlate() mmp_pdma.c implements a custom of_xlate() function that is 95% identical to what Tegra will need. Create a function to implement the common part, so everyone doesn't just cut/paste the implementation. Cc: Dan Williams Cc: Vinod Koul Cc: Lars-Peter Clausen Cc: dmaengine@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Stephen Warren Signed-off-by: Vinod Koul --- drivers/dma/dmaengine.c | 28 ++++++++++++++++++++++++++++ drivers/dma/mmp_pdma.c | 30 +++++++----------------------- include/linux/dmaengine.h | 1 + 3 files changed, 36 insertions(+), 23 deletions(-) (limited to 'include/linux') diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index ea806bdc12ef..4f08ee8c17b4 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -535,6 +535,34 @@ struct dma_chan *dma_get_slave_channel(struct dma_chan *chan) } EXPORT_SYMBOL_GPL(dma_get_slave_channel); +struct dma_chan *dma_get_any_slave_channel(struct dma_device *device) +{ + dma_cap_mask_t mask; + struct dma_chan *chan; + int err; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + /* lock against __dma_request_channel */ + mutex_lock(&dma_list_mutex); + + chan = private_candidate(&mask, device, NULL, NULL); + if (chan) { + err = dma_chan_get(chan); + if (err) { + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + chan = NULL; + } + } + + mutex_unlock(&dma_list_mutex); + + return chan; +} +EXPORT_SYMBOL_GPL(dma_get_any_slave_channel); + /** * __dma_request_channel - try to allocate an exclusive channel * @mask: capabilities that the channel must satisfy diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c index dcb1e05149a7..2998f1bffac1 100644 --- a/drivers/dma/mmp_pdma.c +++ b/drivers/dma/mmp_pdma.c @@ -893,33 +893,17 @@ static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma) { struct mmp_pdma_device *d = ofdma->of_dma_data; - struct dma_chan *chan, *candidate; + struct dma_chan *chan; + struct mmp_pdma_chan *c; -retry: - candidate = NULL; - - /* walk the list of channels registered with the current instance and - * find one that is currently unused */ - list_for_each_entry(chan, &d->device.channels, device_node) - if (chan->client_count == 0) { - candidate = chan; - break; - } - - if (!candidate) + chan = dma_get_any_slave_channel(&d->device); + if (!chan) return NULL; - /* dma_get_slave_channel will return NULL if we lost a race between - * the lookup and the reservation */ - chan = dma_get_slave_channel(candidate); - - if (chan) { - struct mmp_pdma_chan *c = to_mmp_pdma_chan(chan); - c->drcmr = dma_spec->args[0]; - return chan; - } + c = to_mmp_pdma_chan(chan); + c->drcmr = dma_spec->args[0]; - goto retry; + return chan; } static int mmp_pdma_probe(struct platform_device *op) diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 41cf0c399288..09ef23ee8bce 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -1079,6 +1079,7 @@ int dma_async_device_register(struct dma_device *device); void dma_async_device_unregister(struct dma_device *device); void dma_run_dependencies(struct dma_async_tx_descriptor *tx); struct dma_chan *dma_get_slave_channel(struct dma_chan *chan); +struct dma_chan *dma_get_any_slave_channel(struct dma_device *device); struct dma_chan *net_dma_find_channel(void); #define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y) #define dma_request_slave_channel_compat(mask, x, y, dev, name) \ -- cgit From 80b28791ff0416a472e5a555a4b6f5f39df2fc24 Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Wed, 6 Nov 2013 15:45:46 -0700 Subject: ARM: tegra: pass reset to tegra_powergate_sequence_power_up() Tegra's clock driver now provides an implementation of the common reset API (include/linux/reset.h). Use this instead of the old Tegra- specific API; that will soon be removed. Signed-off-by: Stephen Warren Acked-by: Bjorn Helgaas Acked-By: Terje Bergstrom Reviewed-by: Thierry Reding Acked-by: Thierry Reding --- arch/arm/mach-tegra/powergate.c | 8 +++++--- drivers/gpu/drm/tegra/gr3d.c | 6 ++++-- drivers/pci/host/pci-tegra.c | 3 ++- include/linux/tegra-powergate.h | 7 +++++-- 4 files changed, 16 insertions(+), 8 deletions(-) (limited to 'include/linux') diff --git a/arch/arm/mach-tegra/powergate.c b/arch/arm/mach-tegra/powergate.c index 85d28e756bb7..f6f5b54ff95e 100644 --- a/arch/arm/mach-tegra/powergate.c +++ b/arch/arm/mach-tegra/powergate.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -144,11 +145,12 @@ int tegra_powergate_remove_clamping(int id) } /* Must be called with clk disabled, and returns with clk enabled */ -int tegra_powergate_sequence_power_up(int id, struct clk *clk) +int tegra_powergate_sequence_power_up(int id, struct clk *clk, + struct reset_control *rst) { int ret; - tegra_periph_reset_assert(clk); + reset_control_assert(rst); ret = tegra_powergate_power_on(id); if (ret) @@ -165,7 +167,7 @@ int tegra_powergate_sequence_power_up(int id, struct clk *clk) goto err_clamp; udelay(10); - tegra_periph_reset_deassert(clk); + reset_control_deassert(rst); return 0; diff --git a/drivers/gpu/drm/tegra/gr3d.c b/drivers/gpu/drm/tegra/gr3d.c index f629e38b00e4..0cbb24b1ae04 100644 --- a/drivers/gpu/drm/tegra/gr3d.c +++ b/drivers/gpu/drm/tegra/gr3d.c @@ -279,7 +279,8 @@ static int gr3d_probe(struct platform_device *pdev) } } - err = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_3D, gr3d->clk); + err = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_3D, gr3d->clk, + gr3d->rst); if (err < 0) { dev_err(&pdev->dev, "failed to power up 3D unit\n"); return err; @@ -287,7 +288,8 @@ static int gr3d_probe(struct platform_device *pdev) if (gr3d->clk_secondary) { err = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_3D1, - gr3d->clk_secondary); + gr3d->clk_secondary, + gr3d->rst_secondary); if (err < 0) { dev_err(&pdev->dev, "failed to power up secondary 3D unit\n"); diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c index 6681c3182c85..0175041ab728 100644 --- a/drivers/pci/host/pci-tegra.c +++ b/drivers/pci/host/pci-tegra.c @@ -955,7 +955,8 @@ static int tegra_pcie_power_on(struct tegra_pcie *pcie) } err = tegra_powergate_sequence_power_up(TEGRA_POWERGATE_PCIE, - pcie->pex_clk); + pcie->pex_clk, + pcie->pex_rst); if (err) { dev_err(pcie->dev, "powerup sequence failed: %d\n", err); return err; diff --git a/include/linux/tegra-powergate.h b/include/linux/tegra-powergate.h index fd4498329c7c..afe442d2629a 100644 --- a/include/linux/tegra-powergate.h +++ b/include/linux/tegra-powergate.h @@ -19,6 +19,7 @@ #define _MACH_TEGRA_POWERGATE_H_ struct clk; +struct reset_control; #define TEGRA_POWERGATE_CPU 0 #define TEGRA_POWERGATE_3D 1 @@ -52,7 +53,8 @@ int tegra_powergate_power_off(int id); int tegra_powergate_remove_clamping(int id); /* Must be called with clk disabled, and returns with clk enabled */ -int tegra_powergate_sequence_power_up(int id, struct clk *clk); +int tegra_powergate_sequence_power_up(int id, struct clk *clk, + struct reset_control *rst); #else static inline int tegra_powergate_is_powered(int id) { @@ -74,7 +76,8 @@ static inline int tegra_powergate_remove_clamping(int id) return -ENOSYS; } -static inline int tegra_powergate_sequence_power_up(int id, struct clk *clk) +static inline int tegra_powergate_sequence_power_up(int id, struct clk *clk, + struct reset_control *rst); { return -ENOSYS; } -- cgit From 2ae77527bb1a510070d039aaa22d1ae9a5807b6f Mon Sep 17 00:00:00 2001 From: Stephen Warren Date: Wed, 6 Nov 2013 16:58:16 -0700 Subject: clk: tegra: remove legacy reset APIs Now that no code uses the custom Tegra module reset API, we can remove its implementation. Signed-off-by: Stephen Warren Reviewed-by: Thierry Reding Acked-By: Peter De Schrijver --- drivers/clk/tegra/clk-periph-gate.c | 22 -------------------- drivers/clk/tegra/clk-periph.c | 40 ------------------------------------- drivers/clk/tegra/clk.h | 1 - include/linux/clk/tegra.h | 7 ------- 4 files changed, 70 deletions(-) (limited to 'include/linux') diff --git a/drivers/clk/tegra/clk-periph-gate.c b/drivers/clk/tegra/clk-periph-gate.c index f38f33e3c65d..507015314827 100644 --- a/drivers/clk/tegra/clk-periph-gate.c +++ b/drivers/clk/tegra/clk-periph-gate.c @@ -36,8 +36,6 @@ static DEFINE_SPINLOCK(periph_ref_lock); #define read_rst(gate) \ readl_relaxed(gate->clk_base + (gate->regs->rst_reg)) -#define write_rst_set(val, gate) \ - writel_relaxed(val, gate->clk_base + (gate->regs->rst_set_reg)) #define write_rst_clr(val, gate) \ writel_relaxed(val, gate->clk_base + (gate->regs->rst_clr_reg)) @@ -123,26 +121,6 @@ static void clk_periph_disable(struct clk_hw *hw) spin_unlock_irqrestore(&periph_ref_lock, flags); } -void tegra_periph_reset(struct tegra_clk_periph_gate *gate, bool assert) -{ - if (gate->flags & TEGRA_PERIPH_NO_RESET) - return; - - if (assert) { - /* - * If peripheral is in the APB bus then read the APB bus to - * flush the write operation in apb bus. This will avoid the - * peripheral access after disabling clock - */ - if (gate->flags & TEGRA_PERIPH_ON_APB) - tegra_read_chipid(); - - write_rst_set(periph_clk_to_bit(gate), gate); - } else { - write_rst_clr(periph_clk_to_bit(gate), gate); - } -} - const struct clk_ops tegra_clk_periph_gate_ops = { .is_enabled = clk_periph_is_enabled, .enable = clk_periph_enable, diff --git a/drivers/clk/tegra/clk-periph.c b/drivers/clk/tegra/clk-periph.c index d62b396863c1..c534043c0481 100644 --- a/drivers/clk/tegra/clk-periph.c +++ b/drivers/clk/tegra/clk-periph.c @@ -111,46 +111,6 @@ static void clk_periph_disable(struct clk_hw *hw) gate_ops->disable(gate_hw); } -void tegra_periph_reset_deassert(struct clk *c) -{ - struct clk_hw *hw = __clk_get_hw(c); - struct tegra_clk_periph *periph = to_clk_periph(hw); - struct tegra_clk_periph_gate *gate; - - if (periph->magic != TEGRA_CLK_PERIPH_MAGIC) { - gate = to_clk_periph_gate(hw); - if (gate->magic != TEGRA_CLK_PERIPH_GATE_MAGIC) { - WARN_ON(1); - return; - } - } else { - gate = &periph->gate; - } - - tegra_periph_reset(gate, 0); -} -EXPORT_SYMBOL(tegra_periph_reset_deassert); - -void tegra_periph_reset_assert(struct clk *c) -{ - struct clk_hw *hw = __clk_get_hw(c); - struct tegra_clk_periph *periph = to_clk_periph(hw); - struct tegra_clk_periph_gate *gate; - - if (periph->magic != TEGRA_CLK_PERIPH_MAGIC) { - gate = to_clk_periph_gate(hw); - if (gate->magic != TEGRA_CLK_PERIPH_GATE_MAGIC) { - WARN_ON(1); - return; - } - } else { - gate = &periph->gate; - } - - tegra_periph_reset(gate, 1); -} -EXPORT_SYMBOL(tegra_periph_reset_assert); - const struct clk_ops tegra_clk_periph_ops = { .get_parent = clk_periph_get_parent, .set_parent = clk_periph_set_parent, diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h index 07c62f997371..16ec8d6bb87f 100644 --- a/drivers/clk/tegra/clk.h +++ b/drivers/clk/tegra/clk.h @@ -393,7 +393,6 @@ struct tegra_clk_periph_gate { #define TEGRA_PERIPH_NO_DIV BIT(4) #define TEGRA_PERIPH_NO_GATE BIT(5) -void tegra_periph_reset(struct tegra_clk_periph_gate *gate, bool assert); extern const struct clk_ops tegra_clk_periph_gate_ops; struct clk *tegra_clk_register_periph_gate(const char *name, const char *parent_name, u8 gate_flags, void __iomem *clk_base, diff --git a/include/linux/clk/tegra.h b/include/linux/clk/tegra.h index 23a0ceee831f..3ca9fca827a2 100644 --- a/include/linux/clk/tegra.h +++ b/include/linux/clk/tegra.h @@ -120,13 +120,6 @@ static inline void tegra_cpu_clock_resume(void) } #endif -#ifdef CONFIG_ARCH_TEGRA -void tegra_periph_reset_deassert(struct clk *c); -void tegra_periph_reset_assert(struct clk *c); -#else -static inline void tegra_periph_reset_deassert(struct clk *c) {} -static inline void tegra_periph_reset_assert(struct clk *c) {} -#endif void tegra_clocks_apply_init_table(void); #endif /* __LINUX_CLK_TEGRA_H_ */ -- cgit