diff options
Diffstat (limited to 'target/linux/ramips/patches-5.4/0102-staging-mt7621-pci-use-gpios-for-properly-reset.patch')
| -rw-r--r-- | target/linux/ramips/patches-5.4/0102-staging-mt7621-pci-use-gpios-for-properly-reset.patch | 222 |
1 files changed, 222 insertions, 0 deletions
diff --git a/target/linux/ramips/patches-5.4/0102-staging-mt7621-pci-use-gpios-for-properly-reset.patch b/target/linux/ramips/patches-5.4/0102-staging-mt7621-pci-use-gpios-for-properly-reset.patch new file mode 100644 index 0000000000..1b7828f1e6 --- /dev/null +++ b/target/linux/ramips/patches-5.4/0102-staging-mt7621-pci-use-gpios-for-properly-reset.patch @@ -0,0 +1,222 @@ +From 227a8bf421ff8b085444e51e471ef06a87228cfd Mon Sep 17 00:00:00 2001 +From: Sergio Paracuellos <sergio.paracuellos@gmail.com> +Date: Fri, 13 Mar 2020 21:09:08 +0100 +Subject: [PATCH] staging: mt7621-pci: use gpios for properly reset + +Original driver code was using three gpio's for reset +asserts and deasserts the pcis. Instead of using that +a general reset control with a perst gpio was introduced +and it seems it is partially working but sometimes there +are some unexpected hangs on boot. This commit make use of +the three original gpios using 'reset-gpios' property of +the device tree and removes the reset line and perst gpio. +According to the mediatek aplication note v0.1 there are +three gpios used for pcie ports reset control: gpio#19, +gpio#8 and gpio#7 for slots 0, 1 and 2 respectively. +This schema can be used separately for mt7621A but in some +boards due to pin share issue, if the PCM and I2S function +are enable at the same time, there are no enough GPIO to +control per-port PCIe reset. In those cases gpio#19 is enought +for reset the three ports together. Because of this we just +try to get the three gpios but if some of them fail we are not +failing in boot process, just prints a kernel notice and take +after into account if the descriptor is or not valid in order +to use it. All of them are set as GPIO output low configuration. +The gpio descriptor's API takes device tree property into account +and invert value if the pin is configured as active low. +So we also have to properly request pins from device tree +and set values correct in assert and deassert functions. +After this changes the order to make all assert and +deassert in the 'probe' process makes more sense: +* Parse device tree. +* make assert of the RC's and EP's before doing anything else. +* make deassert of the RC's before initializing the phy. +* Init the phy. +* make deassert of the EP's before initialize pci ports. +* Normal PCI initialization. + +Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com> +Link: https://lore.kernel.org/r/20200313200913.24321-2-sergio.paracuellos@gmail.com +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + drivers/staging/mt7621-pci/pci-mt7621.c | 84 ++++++++++++++++++++------------- + 1 file changed, 51 insertions(+), 33 deletions(-) + +--- a/drivers/staging/mt7621-pci/pci-mt7621.c ++++ b/drivers/staging/mt7621-pci/pci-mt7621.c +@@ -95,6 +95,7 @@ + * @pcie: pointer to PCIe host info + * @phy: pointer to PHY control block + * @pcie_rst: pointer to port reset control ++ * @gpio_rst: gpio reset + * @slot: port slot + * @enabled: indicates if port is enabled + */ +@@ -104,6 +105,7 @@ struct mt7621_pcie_port { + struct mt7621_pcie *pcie; + struct phy *phy; + struct reset_control *pcie_rst; ++ struct gpio_desc *gpio_rst; + u32 slot; + bool enabled; + }; +@@ -117,8 +119,6 @@ struct mt7621_pcie_port { + * @offset: IO / Memory offset + * @dev: Pointer to PCIe device + * @ports: pointer to PCIe port information +- * @perst: gpio reset +- * @rst: pointer to pcie reset + * @resets_inverted: depends on chip revision + * reset lines are inverted. + */ +@@ -133,8 +133,6 @@ struct mt7621_pcie { + resource_size_t io; + } offset; + struct list_head ports; +- struct gpio_desc *perst; +- struct reset_control *rst; + bool resets_inverted; + }; + +@@ -210,16 +208,16 @@ static void write_config(struct mt7621_p + pcie_write(pcie, val, RALINK_PCI_CONFIG_DATA); + } + +-static inline void mt7621_perst_gpio_pcie_assert(struct mt7621_pcie *pcie) ++static inline void mt7621_rst_gpio_pcie_assert(struct mt7621_pcie_port *port) + { +- gpiod_set_value(pcie->perst, 0); +- mdelay(PERST_DELAY_US); ++ if (port->gpio_rst) ++ gpiod_set_value(port->gpio_rst, 1); + } + +-static inline void mt7621_perst_gpio_pcie_deassert(struct mt7621_pcie *pcie) ++static inline void mt7621_rst_gpio_pcie_deassert(struct mt7621_pcie_port *port) + { +- gpiod_set_value(pcie->perst, 1); +- mdelay(PERST_DELAY_US); ++ if (port->gpio_rst) ++ gpiod_set_value(port->gpio_rst, 0); + } + + static inline bool mt7621_pcie_port_is_linkup(struct mt7621_pcie_port *port) +@@ -367,6 +365,13 @@ static int mt7621_pcie_parse_port(struct + if (IS_ERR(port->phy)) + return PTR_ERR(port->phy); + ++ port->gpio_rst = devm_gpiod_get_index_optional(dev, "reset", slot, ++ GPIOD_OUT_LOW); ++ if (IS_ERR(port->gpio_rst)) { ++ dev_err(dev, "Failed to get GPIO for PCIe%d\n", slot); ++ return PTR_ERR(port->gpio_rst); ++ } ++ + port->slot = slot; + port->pcie = pcie; + +@@ -383,12 +388,6 @@ static int mt7621_pcie_parse_dt(struct m + struct resource regs; + int err; + +- pcie->perst = devm_gpiod_get(dev, "perst", GPIOD_OUT_HIGH); +- if (IS_ERR(pcie->perst)) { +- dev_err(dev, "failed to get gpio perst\n"); +- return PTR_ERR(pcie->perst); +- } +- + err = of_address_to_resource(node, 0, ®s); + if (err) { + dev_err(dev, "missing \"reg\" property\n"); +@@ -399,12 +398,6 @@ static int mt7621_pcie_parse_dt(struct m + if (IS_ERR(pcie->base)) + return PTR_ERR(pcie->base); + +- pcie->rst = devm_reset_control_get_exclusive(dev, "pcie"); +- if (PTR_ERR(pcie->rst) == -EPROBE_DEFER) { +- dev_err(dev, "failed to get pcie reset control\n"); +- return PTR_ERR(pcie->rst); +- } +- + for_each_available_child_of_node(node, child) { + int slot; + +@@ -458,16 +451,49 @@ static int mt7621_pcie_init_port(struct + return 0; + } + ++static void mt7621_pcie_reset_assert(struct mt7621_pcie *pcie) ++{ ++ struct mt7621_pcie_port *port; ++ ++ list_for_each_entry(port, &pcie->ports, list) { ++ /* PCIe RC reset assert */ ++ mt7621_control_assert(port); ++ ++ /* PCIe EP reset assert */ ++ mt7621_rst_gpio_pcie_assert(port); ++ } ++ ++ mdelay(PERST_DELAY_US); ++} ++ ++static void mt7621_pcie_reset_rc_deassert(struct mt7621_pcie *pcie) ++{ ++ struct mt7621_pcie_port *port; ++ ++ list_for_each_entry(port, &pcie->ports, list) ++ mt7621_control_deassert(port); ++} ++ ++static void mt7621_pcie_reset_ep_deassert(struct mt7621_pcie *pcie) ++{ ++ struct mt7621_pcie_port *port; ++ ++ list_for_each_entry(port, &pcie->ports, list) ++ mt7621_rst_gpio_pcie_deassert(port); ++ ++ mdelay(PERST_DELAY_US); ++} ++ + static void mt7621_pcie_init_ports(struct mt7621_pcie *pcie) + { + struct device *dev = pcie->dev; + struct mt7621_pcie_port *port, *tmp; +- u32 val = 0; + int err; + + rt_sysc_m32(PERST_MODE_MASK, PERST_MODE_GPIO, MT7621_GPIO_MODE); + +- mt7621_perst_gpio_pcie_assert(pcie); ++ mt7621_pcie_reset_assert(pcie); ++ mt7621_pcie_reset_rc_deassert(pcie); + + list_for_each_entry_safe(port, tmp, &pcie->ports, list) { + u32 slot = port->slot; +@@ -476,16 +502,10 @@ static void mt7621_pcie_init_ports(struc + if (err) { + dev_err(dev, "Initiating port %d failed\n", slot); + list_del(&port->list); +- } else { +- val = read_config(pcie, slot, PCIE_FTS_NUM); +- dev_info(dev, "Port %d N_FTS = %x\n", slot, +- (unsigned int)val); + } + } + +- reset_control_assert(pcie->rst); +- +- mt7621_perst_gpio_pcie_deassert(pcie); ++ mt7621_pcie_reset_ep_deassert(pcie); + + list_for_each_entry(port, &pcie->ports, list) { + u32 slot = port->slot; +@@ -499,8 +519,6 @@ static void mt7621_pcie_init_ports(struc + port->enabled = false; + } + } +- +- reset_control_deassert(pcie->rst); + } + + static void mt7621_pcie_enable_port(struct mt7621_pcie_port *port) |