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Diffstat (limited to 'target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch')
-rw-r--r--target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch285
1 files changed, 0 insertions, 285 deletions
diff --git a/target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch b/target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch
deleted file mode 100644
index 592b763b6a..0000000000
--- a/target/linux/generic/backport-5.4/821-v5.8-i2c-pxa-implement-generic-i2c-bus-recovery.patch
+++ /dev/null
@@ -1,285 +0,0 @@
-From: Russell King <rmk+kernel@armlinux.org.uk>
-Bcc: linux@mail.armlinux.org.uk
-Subject: [PATCH 7/7] i2c: pxa: implement generic i2c bus recovery
-MIME-Version: 1.0
-Content-Disposition: inline
-Content-Transfer-Encoding: 8bit
-Content-Type: text/plain; charset="utf-8"
-
-Implement generic GPIO-based I2C bus recovery for the PXA I2C driver.
-
-Reviewed-by: Andrew Lunn <andrew@lunn.ch>
-Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
----
- drivers/i2c/busses/i2c-pxa.c | 176 +++++++++++++++++++++++++++++++----
- 1 file changed, 159 insertions(+), 17 deletions(-)
-
---- a/drivers/i2c/busses/i2c-pxa.c
-+++ b/drivers/i2c/busses/i2c-pxa.c
-@@ -20,6 +20,7 @@
- #include <linux/delay.h>
- #include <linux/err.h>
- #include <linux/errno.h>
-+#include <linux/gpio/consumer.h>
- #include <linux/i2c.h>
- #include <linux/i2c-pxa.h>
- #include <linux/init.h>
-@@ -29,6 +30,7 @@
- #include <linux/module.h>
- #include <linux/of.h>
- #include <linux/of_device.h>
-+#include <linux/pinctrl/consumer.h>
- #include <linux/platform_device.h>
- #include <linux/platform_data/i2c-pxa.h>
- #include <linux/slab.h>
-@@ -261,6 +263,11 @@ struct pxa_i2c {
- bool highmode_enter;
- u32 fm_mask;
- u32 hs_mask;
-+
-+ struct i2c_bus_recovery_info recovery;
-+ struct pinctrl *pinctrl;
-+ struct pinctrl_state *pinctrl_default;
-+ struct pinctrl_state *pinctrl_recovery;
- };
-
- #define _IBMR(i2c) ((i2c)->reg_ibmr)
-@@ -560,13 +567,8 @@ static void i2c_pxa_set_slave(struct pxa
- #define i2c_pxa_set_slave(i2c, err) do { } while (0)
- #endif
-
--static void i2c_pxa_reset(struct pxa_i2c *i2c)
-+static void i2c_pxa_do_reset(struct pxa_i2c *i2c)
- {
-- pr_debug("Resetting I2C Controller Unit\n");
--
-- /* abort any transfer currently under way */
-- i2c_pxa_abort(i2c);
--
- /* reset according to 9.8 */
- writel(ICR_UR, _ICR(i2c));
- writel(I2C_ISR_INIT, _ISR(i2c));
-@@ -585,12 +587,25 @@ static void i2c_pxa_reset(struct pxa_i2c
- #endif
-
- i2c_pxa_set_slave(i2c, 0);
-+}
-
-+static void i2c_pxa_enable(struct pxa_i2c *i2c)
-+{
- /* enable unit */
- writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
- udelay(100);
- }
-
-+static void i2c_pxa_reset(struct pxa_i2c *i2c)
-+{
-+ pr_debug("Resetting I2C Controller Unit\n");
-+
-+ /* abort any transfer currently under way */
-+ i2c_pxa_abort(i2c);
-+ i2c_pxa_do_reset(i2c);
-+ i2c_pxa_enable(i2c);
-+}
-+
-
- #ifdef CONFIG_I2C_PXA_SLAVE
- /*
-@@ -1002,6 +1017,7 @@ static int i2c_pxa_do_xfer(struct pxa_i2
- ret = i2c_pxa_wait_bus_not_busy(i2c);
- if (ret) {
- dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
-+ i2c_recover_bus(&i2c->adap);
- goto out;
- }
-
-@@ -1047,6 +1063,7 @@ static int i2c_pxa_do_xfer(struct pxa_i2
-
- if (!timeout && i2c->msg_num) {
- i2c_pxa_scream_blue_murder(i2c, "timeout with active message");
-+ i2c_recover_bus(&i2c->adap);
- ret = I2C_RETRY;
- }
-
-@@ -1228,6 +1245,129 @@ static int i2c_pxa_probe_pdata(struct pl
- return 0;
- }
-
-+static void i2c_pxa_prepare_recovery(struct i2c_adapter *adap)
-+{
-+ struct pxa_i2c *i2c = adap->algo_data;
-+ u32 ibmr = readl(_IBMR(i2c));
-+
-+ /*
-+ * Program the GPIOs to reflect the current I2C bus state while
-+ * we transition to recovery; this avoids glitching the bus.
-+ */
-+ gpiod_set_value(i2c->recovery.scl_gpiod, ibmr & IBMR_SCLS);
-+ gpiod_set_value(i2c->recovery.sda_gpiod, ibmr & IBMR_SDAS);
-+
-+ WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery));
-+}
-+
-+static void i2c_pxa_unprepare_recovery(struct i2c_adapter *adap)
-+{
-+ struct pxa_i2c *i2c = adap->algo_data;
-+ u32 isr;
-+
-+ /*
-+ * The bus should now be free. Clear up the I2C controller before
-+ * handing control of the bus back to avoid the bus changing state.
-+ */
-+ isr = readl(_ISR(i2c));
-+ if (isr & (ISR_UB | ISR_IBB)) {
-+ dev_dbg(&i2c->adap.dev,
-+ "recovery: resetting controller, ISR=0x%08x\n", isr);
-+ i2c_pxa_do_reset(i2c);
-+ }
-+
-+ WARN_ON(pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default));
-+
-+ dev_dbg(&i2c->adap.dev, "recovery: IBMR 0x%08x ISR 0x%08x\n",
-+ readl(_IBMR(i2c)), readl(_ISR(i2c)));
-+
-+ i2c_pxa_enable(i2c);
-+}
-+
-+static int i2c_pxa_init_recovery(struct pxa_i2c *i2c)
-+{
-+ struct i2c_bus_recovery_info *bri = &i2c->recovery;
-+ struct device *dev = i2c->adap.dev.parent;
-+
-+ /*
-+ * When slave mode is enabled, we are not the only master on the bus.
-+ * Bus recovery can only be performed when we are the master, which
-+ * we can't be certain of. Therefore, when slave mode is enabled, do
-+ * not configure bus recovery.
-+ */
-+ if (IS_ENABLED(CONFIG_I2C_PXA_SLAVE))
-+ return 0;
-+
-+ i2c->pinctrl = devm_pinctrl_get(dev);
-+ if (IS_ERR(i2c->pinctrl))
-+ return PTR_ERR(i2c->pinctrl);
-+
-+ if (!i2c->pinctrl)
-+ return 0;
-+
-+ i2c->pinctrl_default = pinctrl_lookup_state(i2c->pinctrl,
-+ PINCTRL_STATE_DEFAULT);
-+ i2c->pinctrl_recovery = pinctrl_lookup_state(i2c->pinctrl, "recovery");
-+
-+ if (IS_ERR(i2c->pinctrl_default) || IS_ERR(i2c->pinctrl_recovery)) {
-+ dev_info(dev, "missing pinmux recovery information: %ld %ld\n",
-+ PTR_ERR(i2c->pinctrl_default),
-+ PTR_ERR(i2c->pinctrl_recovery));
-+ return 0;
-+ }
-+
-+ /*
-+ * Claiming GPIOs can influence the pinmux state, and may glitch the
-+ * I2C bus. Do this carefully.
-+ */
-+ bri->scl_gpiod = devm_gpiod_get(dev, "scl", GPIOD_OUT_HIGH_OPEN_DRAIN);
-+ if (bri->scl_gpiod == ERR_PTR(-EPROBE_DEFER))
-+ return -EPROBE_DEFER;
-+ if (IS_ERR(bri->scl_gpiod)) {
-+ dev_info(dev, "missing scl gpio recovery information: %pe\n",
-+ bri->scl_gpiod);
-+ return 0;
-+ }
-+
-+ /*
-+ * We have SCL. Pull SCL low and wait a bit so that SDA glitches
-+ * have no effect.
-+ */
-+ gpiod_direction_output(bri->scl_gpiod, 0);
-+ udelay(10);
-+ bri->sda_gpiod = devm_gpiod_get(dev, "sda", GPIOD_OUT_HIGH_OPEN_DRAIN);
-+
-+ /* Wait a bit in case of a SDA glitch, and then release SCL. */
-+ udelay(10);
-+ gpiod_direction_output(bri->scl_gpiod, 1);
-+
-+ if (bri->sda_gpiod == ERR_PTR(-EPROBE_DEFER))
-+ return -EPROBE_DEFER;
-+
-+ if (IS_ERR(bri->sda_gpiod)) {
-+ dev_info(dev, "missing sda gpio recovery information: %pe\n",
-+ bri->sda_gpiod);
-+ return 0;
-+ }
-+
-+ bri->prepare_recovery = i2c_pxa_prepare_recovery;
-+ bri->unprepare_recovery = i2c_pxa_unprepare_recovery;
-+ bri->recover_bus = i2c_generic_scl_recovery;
-+
-+ i2c->adap.bus_recovery_info = bri;
-+
-+ /*
-+ * Claiming GPIOs can change the pinmux state, which confuses the
-+ * pinctrl since pinctrl's idea of the current setting is unaffected
-+ * by the pinmux change caused by claiming the GPIO. Work around that
-+ * by switching pinctrl to the GPIO state here. We do it this way to
-+ * avoid glitching the I2C bus.
-+ */
-+ pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_recovery);
-+
-+ return pinctrl_select_state(i2c->pinctrl, i2c->pinctrl_default);
-+}
-+
- static int i2c_pxa_probe(struct platform_device *dev)
- {
- struct i2c_pxa_platform_data *plat = dev_get_platdata(&dev->dev);
-@@ -1240,6 +1380,16 @@ static int i2c_pxa_probe(struct platform
- if (!i2c)
- return -ENOMEM;
-
-+ /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
-+ i2c->adap.nr = dev->id;
-+ i2c->adap.owner = THIS_MODULE;
-+ i2c->adap.retries = 5;
-+ i2c->adap.algo_data = i2c;
-+ i2c->adap.dev.parent = &dev->dev;
-+#ifdef CONFIG_OF
-+ i2c->adap.dev.of_node = dev->dev.of_node;
-+#endif
-+
- res = platform_get_resource(dev, IORESOURCE_MEM, 0);
- i2c->reg_base = devm_ioremap_resource(&dev->dev, res);
- if (IS_ERR(i2c->reg_base))
-@@ -1251,8 +1401,9 @@ static int i2c_pxa_probe(struct platform
- return irq;
- }
-
-- /* Default adapter num to device id; i2c_pxa_probe_dt can override. */
-- i2c->adap.nr = dev->id;
-+ ret = i2c_pxa_init_recovery(i2c);
-+ if (ret)
-+ return ret;
-
- ret = i2c_pxa_probe_dt(dev, i2c, &i2c_type);
- if (ret > 0)
-@@ -1260,9 +1411,6 @@ static int i2c_pxa_probe(struct platform
- if (ret < 0)
- return ret;
-
-- i2c->adap.owner = THIS_MODULE;
-- i2c->adap.retries = 5;
--
- spin_lock_init(&i2c->lock);
- init_waitqueue_head(&i2c->wait);
-
-@@ -1332,12 +1480,6 @@ static int i2c_pxa_probe(struct platform
-
- i2c_pxa_reset(i2c);
-
-- i2c->adap.algo_data = i2c;
-- i2c->adap.dev.parent = &dev->dev;
--#ifdef CONFIG_OF
-- i2c->adap.dev.of_node = dev->dev.of_node;
--#endif
--
- ret = i2c_add_numbered_adapter(&i2c->adap);
- if (ret < 0)
- goto ereqirq;
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-29 07:34:23 +0000