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Date: Wed, 27 May 2020 00:55:17 +0300 From: Serge Semin <Sergey.Semin@...kalelectronics.ru> To: Jarkko Nikula <jarkko.nikula@...ux.intel.com>, Wolfram Sang <wsa@...-dreams.de>, Rob Herring <robh+dt@...nel.org>, Frank Rowand <frowand.list@...il.com> CC: Serge Semin <Sergey.Semin@...kalelectronics.ru>, Serge Semin <fancer.lancer@...il.com>, Alexey Malahov <Alexey.Malahov@...kalelectronics.ru>, Thomas Bogendoerfer <tsbogend@...ha.franken.de>, Mika Westerberg <mika.westerberg@...ux.intel.com>, <linux-mips@...r.kernel.org>, <linux-i2c@...r.kernel.org>, <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org> Subject: [PATCH v3 01/12] scripts/dtc: check: Add 10bit/slave i2c reg flags support Recently the I2C-controllers slave interface support was added to the kernel I2C subsystem. In this case Linux can be used as, for example, a I2C EEPROM machine. See [1] for details. Other than instantiating the EEPROM-slave device from user-space there is a way to declare the device in dts. In this case firstly the I2C bus controller must support the slave interface. Secondly I2C-slave sub-node of that controller must have "reg"-property with flag I2C_OWN_SLAVE_ADDRESS set (flag is declared in [2]). That flag is declared as (1 << 30), which when set makes dtc unhappy about too big address set for a I2C-slave: Warning (i2c_bus_reg): /example-2/i2c@...0000/eeprom@64: I2C bus unit address format error, expected "40000064" Warning (i2c_bus_reg): /example-2/i2c@...0000/eeprom@64:reg: I2C address must be less than 10-bits, got "0x40000064" Similar problem would have happened if we had set the 10-bit address flag I2C_TEN_BIT_ADDRESS in the "reg"-property. In order to fix the problem we suggest to alter the I2C-bus reg-check algorithm, so one would be aware of the upper bits set. Normally if no flag specified, the 7-bit address is expected in the "reg"-property. If I2C_TEN_BIT_ADDRESS is set, then the 10-bit address check will be performed. The I2C_OWN_SLAVE_ADDRESS flag will be just ignored. [1] Documentation/i2c/slave-interface.rst [2] include/dt-bindings/i2c/i2c.h Signed-off-by: Serge Semin <Sergey.Semin@...kalelectronics.ru> Cc: Alexey Malahov <Alexey.Malahov@...kalelectronics.ru> Cc: Thomas Bogendoerfer <tsbogend@...ha.franken.de> Cc: Mika Westerberg <mika.westerberg@...ux.intel.com> Cc: linux-mips@...r.kernel.org Cc: linux-i2c@...r.kernel.org --- scripts/dtc/checks.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/scripts/dtc/checks.c b/scripts/dtc/checks.c index 4b3c486f1399..6321fc5b7404 100644 --- a/scripts/dtc/checks.c +++ b/scripts/dtc/checks.c @@ -1028,6 +1028,7 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node const char *unitname = get_unitname(node); char unit_addr[17]; uint32_t reg = 0; + uint32_t addr; int len; cell_t *cells = NULL; @@ -1044,17 +1045,21 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node } reg = fdt32_to_cpu(*cells); - snprintf(unit_addr, sizeof(unit_addr), "%x", reg); + addr = reg & 0x3FFFFFFFU; + snprintf(unit_addr, sizeof(unit_addr), "%x", addr); if (!streq(unitname, unit_addr)) FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"", unit_addr); for (len = prop->val.len; len > 0; len -= 4) { reg = fdt32_to_cpu(*(cells++)); - if (reg > 0x3ff) + addr = reg & 0x3FFFFFFFU; + if ((reg & (1 << 31)) && addr > 0x3ff) FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"", - reg); - + addr); + else if (!(reg & (1 << 31)) && addr > 0x7f) + FAIL_PROP(c, dti, node, prop, "I2C address must be less than 7-bits, got \"0x%x\"", + addr); } } WARNING(i2c_bus_reg, check_i2c_bus_reg, NULL, ®_format, &i2c_bus_bridge); -- 2.26.2
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